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chris@panteg
09-05-2011, 09:30
{discussion moved from elsewhere}



Hi Chris,

Glad you enjoyed the system. Del and I certainly enjoyed having Alex and you round. It was a pleasure :)

If I didn't have other things going on during the remaining weekends of the month, we could've got the needle-drops done sooner, as the bits needed should all be here by next week.

However, let's hope it's like the saying goes: 'all good things come to those who wait'.... :eyebrows:

I think the attenuators should work ok, but if not, then it'll simply be a case of using one of my MM cartridges instead, without the need for an SUT to complicate matters.



Chris, if you need any cartridge leads, let me know. I've got loads of the buggers! Hope you sort things out soon :cool:

Btw, I've been following the new platter thread on the Timestep forum with interest...

I presume that everyone knows that the acrylic platter has been designed by Arthur K, from Funk? ;)

Design-wise, it has bugger all to do with Dave C.

Marco.

Is it Acrylic ? I thought it might be Lexan , if it is Acrylic , £500 is ridiculous IMHO , there is a difference and if he's gone for the former then i feel its a chance missed , cos IMHO Lexan is far superior !

Doesn't surprise me about Arthur ;)

Marco
09-05-2011, 09:44
Hi Chris,

Don't quote me on the acrylic bit, as I'm not sure about that. It simply looks like acrylic, therefore I referred to it as such. I didn't ask Arthur about what the platter was made of when I spoke with him the other day.

Why not ask Dave what it's made of? I'm sure he'll give you a straight answer, as usual! :eyebrows:


Doesn't surprise me about Arthur...


Indeed. The fact is, Dave doesn't have the ability to design and produce a platter. He's a sales and marketing man with some test equipment ;)

Arthur's sending me one of the new platters to assess in a few weeks. I'll be testing it against the Mike New one, and in due course, reporting my findings here. So look out for that one.......... We don't miss a trick on AoS!

Marco.

pure sound
09-05-2011, 09:50
Is it Acrylic ? I thought it might be Lexan , if it is Acrylic , £500 is ridiculous IMHO , there is a difference and if he's gone for the former then i feel its a chance missed , cos IMHO Lexan is far superior !

Doesn't surprise me about Arthur ;)

The problem with making such platters is the need to start from an 8' x 4' sheet. A sheet of 25mm acrylic is expensive enough but can be sawn into 32 platter squares before machining. The cost per platter can be kept reasonable. However, check out the cost of a similarly sized sheet of 25mm Lexan :eek:

The platter pictured on the Timestep forum appears to be acrylic. It must have to incorporate the magnet ring etc from the original platter somehow.
I suppose this is taking the deck in the direction of the Goldmund Studio or Brinkmann Bardo (which isn't necessarily a bad thing)

chris@panteg
09-05-2011, 09:55
Hi Chris,

Don't quote me on the acrylic bit, as I'm not sure about that. It simply looks like acrylic, therefore I referred to it as such. I didn't ask Arthur about what the platter was made of when I spoke with him the other day.

Why not ask Dave what it's made of? I'm sure he'll give you a straight answer, as usual! :eyebrows:



Indeed. The fact is, Dave doesn't have the ability to design and produce a platter. He's a sales and marketing man ;)

Arthur's sending me one of the new platters to assess in a few weeks, so I'll be testing it against the Mike New one, and in due course, reporting my findings here, so look out for that one.......... We don't miss a trick on AoS!

Marco.

Its not what you know eh , blimey if it is Lexan , then i think it could be amazing , it works brilliantly on the Voyd and i don't see why not on the 1210/1200 , if its Acrylic , well it could still be good but.....

I must confess to being very interested in this .

chris@panteg
09-05-2011, 10:00
The problem with making such platters is the need to start from an 8' x 4' sheet. A sheet of 25mm acrylic is expensive enough but can be sawn into 32 platter squares before machining. The cost per platter can be kept reasonable. However, check out the cost of a similarly sized sheet of 25mm Lexan :eek:

The platter pictured on the Timestep forum appears to be acrylic. It must have to incorporate the magnet ring etc from the original platter somehow.
I suppose this is taking the deck in the direction of the Goldmund Studio or Brinkmann Bardo (which isn't necessarily a bad thing)

Hi Guy

I guess its down to quantities as well , Project sell bucket loads of decks with acrylic platter's .

Marco
09-05-2011, 10:12
Hi Guy,

Nice to see you popping in again :)

I'll find out if it's acrylic or not and report back... Like you though, I suspect that it is. It'll certainly be interesting comparing it to the Mike New one.

And I PROMISE everyone that I'll give an unbiased verdict. As much as everyone knows I'm not Dave's biggest fan, I simply wouldn't allow that to cloud my opinion, as I'd like to think I have some credibility to protect.

If the new 'Timestep' platter is better, in my opinion, on my T/T in the context of my system (therefore what I report as usual will not in any way be definitive), then I'll say so.

However, there will be no quick decision on this, as getting a proper handle on how platters (and mats) affect the musical reproduction of a turntable takes time and frequent switching back and forth to one's current reference, for comparison purposes. I also, of course, still have the original Technics platter, so that will be included in the equation.

If the 'Timestep' platter is acrylic, it won't surprise me, as that will have allowed Dave to obtain the profit margin he wanted to make originally, selling Mike's platter, which of course wasn't possible when he stole his design and tried to have a high quality aluminium platter produced in the UK (the whole reason for their fall-out).

I'll confirm later what the 'Timestep' platter is actually made from when I have the info.

Marco.

YNWaN
09-05-2011, 14:20
If Guy thinks it is acrylic it probably is - Lexan seems to have a grey (colour, not sound) hint to it when I have encountered it. I have to say that my own experiments with acrylic have not been at all promisiing and I have found it to have a very distictive sonic signature (coloration). However, I can see the point in trying to keep the rotational mass low.


I suppose this is taking the deck in the direction of the Goldmund Studio or Brinkmann Bardo (which isn't necessarily a bad thing)

I thought the platter on the Bardo was aluminium (with the option of the glass mat)?

Spectral Morn
09-05-2011, 14:49
Looks very interesting....

http://www.soundhifi.com/FOURUMIMAGES/platter3.jpg

I liked the sound of the Pink Triangles and Voyd TT that had light weight platters......still miss the Voyd Valdi I had.


Regards D S D L

REXTON
09-05-2011, 14:57
Those feet look crap to me!

Spectral Morn
09-05-2011, 15:02
Those feet look crap to me! True but in fairness might be very good with the Technics. I use Isonoes myself but have not tried those particular feet, so can't say more than I think the Isonoes look much better.


Regards D S D L

Ammonite Acoustics
09-05-2011, 15:49
It must be acrylic, since the option of a black platter was mentioned, and I'm not aware of Lexan (polycarbonate) being available in black. Also, as YNWaN says, polycarbonate does have different look to it. It's also (I'm reliably informed) very tricky to machine and expensive as a result. Whatever, the Timestep platter will result in a quite different sonic feel to that of the MN platter. Which is best can only be determined by listening.

pure sound
09-05-2011, 16:09
I thought the platter on the Bardo was aluminium (with the option of the glass mat)?

Ah, it may well be. For some reason I'd assumed it was a black delrin or similar. However, given Herr Brinkmann's preferences elsewhere I suppose it would be odd if he was using a polymer platter on the Bardo.

Marco it would be interesting to hear what differences were audible between the two approaches. On the one hand extra mass and a bi-metallic construction. On the other, presumably a lighter platter, more under the control (perhaps) of the motor circuitry with the supposedly advantageous properties of a closer acoustic impedance match to that of the vinyl. I'm surprised the achromat isn't the mat of choice with the second option (if Arthur K has been involved) rather than the 'Herbie's' type. I suppose a like for like comparison might be difficult unless both platters can be used with the same bearing?


I don't think Lexan was particularly difficult to machine. I certainly don't recall any issues with having it done back in my Voyd days. It was just very expensive in sheet form!

colinB
09-05-2011, 16:41
Why not just put a acrylic mat on the platter. SRM do a 3mm one for thirty quid.

Marco
09-05-2011, 16:48
Hi Guy,


Marco it would be interesting to hear what differences were audible between the two approaches. On the one hand extra mass and a bi-metallic construction. On the other, presumably a lighter platter, more under the control (perhaps) of the motor circuitry with the supposedly advantageous properties of a closer acoustic impedance match to that of the vinyl.


Indeed it will. My only comment so far on the 'Timestep' platter is that, aesthetically, I'm not a fan of the 'frosted plastic look', whether it's acrylic or Lexan. For me it looks quite cheap and has been done to death by the likes of Clearaudio, and many others. But I guess it's partly a 'fashion' thing at the moment.

Therefore the combination of the (to me) rather ugly plastic platter on the (to me) rather dull looking MKII 1210 (sorry folks!) is rather an exercise in blandness. It just looks somewhat too 'sober' for my liking.

Perhaps I'm biased, but I much prefer the appearance of Mike New's platter, when suitably polished, on a nice shiny black MK5 Techy:


http://img823.imageshack.us/img823/3091/eimg0502.jpg (http://imageshack.us/photo/my-images/823/eimg0502.jpg/)


For me, that looks far nicer and classier than the 1210 pictured on the Timestep forum, shown earlier :)

Sonically, as yet, I've no idea which platter is better. All will be revealed in due course. I certainly won't let the looks of the acrylic one put me off.

One question I'd ask, however - is the acrylic platter a bigger size than normal? The reason I ask is that it appears to dwarf what looks like a normal LP....


I suppose a like for like comparison might be difficult unless both platters can be used with the same bearing?


Don't see why not. What difficulty would you see the acrylic platter presenting an MN bearing? Also, when I spoke with Arthur, he never indicated that the platter required the use of a certain bearing.

Btw, on a totally unrelated matter, since I've got your attention.... When you do needle-drops with your SP10, using your Io (and matching SUT), how do you overcome the issue of overloading the USB device/sound-card with excessive gain (presuming that this is the case)?

Chris (Stratmangler) and I tried doing some needle-drops at the weekend with my Techy, and with my SPU and A23 SUT, through the Croft and into the EMU USB device, we were unable to adjust the recording levels to anything like normal, due to the excessive gain being produced by the A23.

I presuming that with your Io being even lower output than my SPU, the SUT you use will be very high gain, and thus will present the same difficulties as we had in my system? Or if not, what's happening at your end that isn't happening at mine? Any advice would be appreciated! :)

I'm planning to buy a pair of 6db in-line attenuators to try and solve the problem, but if there's a better solution, I'm all ears! :cool:

Marco.

YNWaN
09-05-2011, 18:33
Looks the same diameter as yours is to me Marco, except the outer diameter is carried up to the level of the record rather than waisted as yours is. In the case of your platter I expect this is to lower the centre of gravity whilst the intention on the latter will be to maximise rotational inertia.

MCRU
09-05-2011, 19:09
Have you put your order in for a platter then Marco? Wait until mine is ready then maybe do a head to head or "bake off" as its known in the trade?

Marco
09-05-2011, 19:13
Hi Mark,

Yup, I guess you're right. It just looks a little strange...


Have you put your order in for a platter then Marco? Wait until mine is ready then maybe do a head to head or "bake off" as its known in the trade?


Don't need to put an order in, dude. Arthur's sending me one to try. A bake-off sounds cool! Your place or mine? :cool:

Marco.

pure sound
09-05-2011, 20:47
Btw, on a totally unrelated matter, since I've got your attention.... When you do needle-drops with your SP10, using your Io (and matching SUT), how do you overcome the issue of overloading the USB device/sound-card with excessive gain (presuming that this is the case)?



Fair enough re Dave C & Arthur K. I'm not aware of any of that.

With regard to recording; I don't use a Soundcard/USB device. I just use a cheap Tascam CD Recorder and burn the tracks to a blank disc which I then take to my computer, import & upload. If the recording needs the start or finish editing I do that in Wavepad but I don't use any normalising or level adjustment. Recording level is set at the CD Recorder. Actually I set the recorder to highest sensitivity & use the gain control on my phono stage to set to the desired level.

I'm sure there must be much better ADC's about now. I probably should try one. However, it isn't something I do often enough to make it a priority.

YNWaN
09-05-2011, 21:14
Guy, I think your recording method works rather well - in addition, I have grown to share your views regarding normalisation and level adjustment.

Can I ask your views on Lexan (polycarbonate) versus acrylic? How would you compare their sonic signatures?

mike1210
09-05-2011, 21:34
Btw, on a totally unrelated matter, since I've got your attention.... When you do needle-drops with your SP10, using your Io (and matching SUT), how do you overcome the issue of overloading the USB device/sound-card with excessive gain (presuming that this is the case)?

Chris (Stratmangler) and I tried doing some needle-drops at the weekend with my Techy, and with my SPU and A23 SUT, through the Croft and into the EMU USB device, we were unable to adjust the recording levels to anything like normal, due to the excessive gain being produced by the A23.

I presuming that with your Io being even lower output than my SPU, the SUT you use will be very high gain, and thus will present the same difficulties as we had in my system? Or if not, what's happening at your end that isn't happening at mine? Any advice would be appreciated! :)

I'm planning to buy a pair of 6db in-line attenuators to try and solve the problem, but if there's a better solution, I'm all ears! :cool:

Marco.

Marco I had a similar problem with my 1210 using a Trichord Dino, the output would nuke my SoundBlaster Live, further reading I discovered I needed a soundcard with pre trim on the inputs. Reading forums and the like they said many phonostages wil overload PC inputs unless pre-trimmed.

I got a Focusrite Saffire which has seperate input gain levels so you can level out the recording well.

Is that what you meant, sorry if I read it wrong

Stratmangler
09-05-2011, 21:51
Marco I had a similar problem with my 1210 using a Trichord Dino, the output would nuke my SoundBlaster Live, further reading I discovered I needed a soundcard with pre trim on the inputs. Reading forums and the like they said many phonostages wil overload PC inputs unless pre-trimmed.

I got a Focusrite Saffire which has seperate input gain levels so you can level out the recording well.

Is that what you meant, sorry if I read it wrong

Hi Mike

You read it right - nuking the inputs is a good description of what was happening on Saturday with the SUTs in circuit.

Cutting the levels by half with line attenuators should do the trick.

Marco
09-05-2011, 22:04
With regard to recording; I don't use a Soundcard/USB device. I just use a cheap Tascam CD Recorder and burn the tracks to a blank disc which I then take to my computer, import & upload. If the recording needs the start or finish editing I do that in Wavepad but I don't use any normalising or level adjustment. Recording level is set at the CD Recorder. Actually I set the recorder to highest sensitivity & use the gain control on my phono stage to set to the desired level.


Sorry, mate, but I'm afraid that's all double-Dutch to me... :scratch:

Could you explain what you do, step by step, in simple layman's terms? Churz!

Marco.

Marco
09-05-2011, 22:05
Hi Chris,


You read it right - nuking the inputs is a good description of what was happening on Saturday with the SUTs in circuit.

Cutting the levels by half with line attenuators should do the trick.

Let's hope so. What do you make of Mike's suggestion though in comparison - or how Guy does it (presuming that, unlike me, you understand his method)? :)

Marco.

YNWaN
09-05-2011, 22:11
Guy has a bit of Pro audio equipment made by Tascam - it's like a tape deck but records to CD and has it's own A2D and D2A built in.

Marco
09-05-2011, 22:19
Cool. So would it be better buying one of these than having a sound-card?

Basically, I'm looking for the simplest, quickest, best sounding solution possible, for non-technical numpties, where high gain from my SUT isn't an issue.

Therefore, I'm open to all suggestions :)

Marco.

Stratmangler
09-05-2011, 22:31
Hi Chris,



Let's hope so. What do you make of Mike's suggestion though in comparison? :)

Marco.

Trimming down the input level is exactly what is required - the device Mike mentioned looks like it has more control over signal level than the EMU0202.
I've just been scanning through the user manual, and there is a -10dB pad that can switched in to calm the signal for each channel. So there is greater inbuilt flexibility than you get with the EMU.
I still reckon that a -6dB line attenuation would be more than adequate to bring the input levels into line.

To be honest I found it difficult to believe just how much gain the SUT brought to the party.
I knew that the signal from a low output MC was pretty puny, and that SUTs boot that level up considerably, but I didn't expect the levels to be booted up quite that much.

I've done quite a few recordings of my own TT running a MM cart into a stand alone phono stage, and never had the levels come in so hot.

mike1210
09-05-2011, 22:45
http://www.zikinf.com/materiel/photos.php?m=524&p=0

FYI

Top 2 knobs do the gain, there are newer cards out now mind from Focusrite

I then got Mark Grant 1/4 inch Jack to Phono connectors to go from the Dino the input on the Card, made from the 1000HD leads

chris@panteg
09-05-2011, 23:17
Why not just put a acrylic mat on the platter. SRM do a 3mm one for thirty quid.

I tried one , it didn't fit properly and sounded a bit hard and shiny , in fact just the way it looks , also because the surface was so shiny , it may be best to use a thin neoprene mat with it .

Marco
09-05-2011, 23:42
Trimming down the input level is exactly what is required - the device Mike mentioned looks like it has more control over signal level than the EMU0202.


I agree. I suppose that putting some 6db phono attenuators in-line is effectively the same as using the gain control switches on Mike's Saffire :)

Marco.

Stratmangler
09-05-2011, 23:47
I agree. I suppose that putting some 6db phono attenuators in-line is effectively the same as using the gain control switches on Mike's Saffire :)

Marco.

Yup :)

Marco
10-05-2011, 08:54
Returning to the new platter, I can now confirm that it is 'museum-grade' acrylic.

I'm sure that this will be a huge improvement on the stock Techy platter, and so I look forward to testing it :)

Marco.

YNWaN
10-05-2011, 09:05
'Museum grade' acrylic - I've used a lot of acrylic in the past and I've never heard that description before! If museums do require a particular quality I would have thought it was transparency - not all that relevant in this case.
___________

Marco, the easiest way to record your vinyly is to take the output from your pre-amp into somrthinh like the Rowland A2D/D2A and then plug it vias USB into a laptop. Then use Audacity as the recording software - job done.

Marco
10-05-2011, 09:31
Hi Mark,

I didn't go into detail about it when I spoke with Arthur, but that's what he said it was made from. It's a lot of money for acrylic; although I've been assured that it's a high quality item, finished to a superb standard.

Knowing Arthur, I don't doubt it. I'm expecting good things from this platter, so I'm sure it will be an excellent alternative to the Mike New one.

Choice is good!

It also shows that more and more designers and influential people are recognising that the Techy is a serious audiophile turntable, and so anything that keeps it in the 'limelight', so to speak, is good in my book :)

Marco.

Marco
10-05-2011, 09:36
Marco, the easiest way to record your vinyly is to take the output from your pre-amp into somrthinh like the Rowland A2D/D2A and then plug it vias USB into a laptop. Then use Audacity as the recording software - job done.


Thanks, Mark. I'll bear that in mind. However, since I've already bought the EMU sound-card, which I've been informed is good, I'd like to persevere with that for the moment.

If in the end it doesn't work properly in my set-up, then I'll obtain the Rowland you mention, and do it that way :)

Marco.

YNWaN
10-05-2011, 09:38
Here ya go, found this description:


Perspex VA Museum Grade is a colourless, cast acrylic sheet with integral UV protection and is suitable for specialist glazing applications and display cases. Perspex® VE is characterised by a slight yellow hue, derived from the UV inhibitor which acts to block out 99.99% of UV rays and is intended more for the protection of highly sensitive museum exhibits.

Doesn't seem to contradict my earlier thoughts.
____________________

Sorry, didn't realise you had bought the soundcard - thought you were borrowing it.

Marco
10-05-2011, 09:42
No, but it doesn't mean that it's not a good material from which to make a turntable platter... I suspect that 'museum-grade' quality acrylic was chosen simply to ensure a nicer finish. It might also be better to work with.

Would you like me to obtain more info? It's not a problem :)

TBH, the only thing I'm interested in is how it sounds!

Marco.

pure sound
10-05-2011, 10:01
"museum grade!" I can imagine the reaction of plastics stockholders (or indeed engineering companies) if I called specifying "museum grade" acrylic for a particular job :lol:

Given that the platter pictured appears to have been gritblasted to opaque, it rather defeats the object of having fine optical characteristics.

Marco. A CD recorder is as easy to use as a cassette deck. The Tascam one is handy as it will write to bog standard blank 'data' recordable CD's which are as cheap as chips nowadays. Once you've made a few recordings to a disk, you finalise it (one button to press) and the machine then closes the disc so that it can be played on any other CD player just as any ordinary music disc would. You can then rip those files from the CD into your computer as you might with tracks from a normal music cd. Once the .wav files are on your computer, you can upload them to a site like mediafire so anyone else can download them.

Here's a decent machine. this will likely be better than what I have.

http://cgi.ebay.co.uk/TASCAM-CD-RW900-CD-Rewritable-Recorder-MINT-cond-/260778160233?pt=UK_Recorders_Rewriters&hash=item3cb796f069

The only limitation is that the format is 16/44 but I think its good enough to give an idea of what a deck is doing. I don't think it sounds quite as good as hearing the deck at first hand, but tbh there are bigger variations in LP sound quality from one LP to another than what might be lost if recording from a good LP in this way. Certainly LP's I've recorded to CD for the car retain enough of what makes the LP sound good which suggests that the 16/44 is not far off what's needed & perhaps the poor mastering of many CD's is the format's achilles heel rather than too low a sampling rate or word size.

chris@panteg
10-05-2011, 10:04
No, but it doesn't mean that it's not a good material from which to make a turntable platter... I suspect that 'museum-grade' quality acrylic was chosen simply to ensure a nicer finish. It might also be better to work with.

Would you like me to obtain more info? It's not a problem :)

TBH, the only thing I'm interested in is how it sounds!

Marco.

I think it could be very good , Arthur wouldn't be doing it otherwise would he ? i suspect its something he's been looking at for some time .

One other thing , it shouldn't really need any mat i would have thought , but i read somewhere that Arthur recommends the Achromat even on old PT's .

Marco
10-05-2011, 10:08
Hi Guy,

Thanks for that - most interesting. I'll defo try one of those and compare the results I get with using the EMU. However, let's see what sort of quality is obtained first when Chris and I use the in-line attenuators.

I have to say that what I've heard so far, whilst not perfect, is rather encouraging!


"museum grade!" I can imagine the reaction of plastics stockholders (or indeed engineering companies) if I called specifying "museum grade" acrylic for a particular job :lol:


Lol - I'm only reporting what I've been told. At least you heard it here first! ;)

Marco.

pure sound
10-05-2011, 10:09
YNWaN. My Voyd is currently having a rest. (Only room for one functional TT here) When I set it up again I'll do some needledrops of records played on the acrylic & then the Lexan platter. It'll be instructive to see whether the difference is audible.

Marco
10-05-2011, 10:13
Hi Chris,


I think it could be very good , Arthur wouldn't be doing it otherwise would he ? i suspect its something he's been looking at for some time.


Indeed! It's only because Arthur's involved that I'm giving this platter any credibility ;)


One other thing , it shouldn't really need any mat i would have thought , but i read somewhere that Arthur recommends the Achromat even on old PT's .

I agree, and when I have the platter, that's something I'll try - both with and without an Achromat. It's all interesting stuff! :cool:

Marco.

YNWaN
10-05-2011, 10:17
YNWaN. My Voyd is currently having a rest. (Only room for one functional TT here) When I set it up again I'll do some needledrops of records played on the acrylic & then the Lexan platter. It'll be instructive to see whether the difference is audible.

Ah yes, didn't realise you had both options - that would be most informative :), many thanks.

chris@panteg
10-05-2011, 11:01
Ah yes, didn't realise you had both options - that would be most informative :), many thanks.

Mark

FWIW , the difference is subtle but important IMHO , as it should be , if it was gobsmackingly huge then you would have to wonder if something's wrong with the design ?

pure sound
10-05-2011, 11:17
I do also have a 10mm Lexan mat for my SP10 which sounds good but it's thickness means that there isn't much spindle left if I choose or need to use a clamp.

Lexan is interesting stuff, dealing with shock very differently to acrylic. Drop an acrylic platter onto a concrete floor (Don't!) and its likely that a piece will chip off. Drop a Lexan platter and it will just bounce. The shock is dissipated more efficiently. Hence, I suppose why it is used for crash helmets and as vandalproof glass in bus shelters etc.

It does have a different characteristic when records are played on it to acrylic, but rather than try to describe it I'll do some Needledrops when the opportunity arises.

The bubble filled achromat material also has different properties to acrylic and also supposedly converts vibration to heat more efficiently than acrylic does.

chris@panteg
10-05-2011, 11:24
I do also have a 10mm Lexan mat for my SP10 which sounds good but it's thickness means that there isn't much spindle left if I choose or need to use a clamp.

Lexan is interesting stuff, dealing with shock very differently to acrylic. Drop an acrylic platter onto a concrete floor (Don't!) and its likely that a piece will chip off. Drop a Lexan platter and it will just bounce. The shock is dissipated more efficiently. Hence, I suppose why it is used for crash helmets and as vandalproof glass in bus shelters etc.

It does have a different characteristic when records are played on it to acrylic, but rather than try to describe it I'll do some Needledrops when the opportunity arises.

The bubble filled achromat material also has different properties to acrylic and also supposedly converts vibration to heat more efficiently than acrylic does.

Hi Guy

I know about Lexan's ability to resist shock , all car headlight lenses are now made from Lexan , i tried to break one once with a lump hammer , it just flew off and out of my hand , it was very funny watching my project manager trying the same :eyebrows:

Mike_New
11-05-2011, 10:17
Hi Folks.

Some observations on the use of a non-metallic material for the Platter of a Direct Drive System such as the SL1200.

I have been following this thread for some time now and have remained silent and in the background as I read all the observations, and absorbed the euphoria, mainly prompted by the snake oil salesmanship of others.

However, I have been prompted by some to make a few observations. Also I would state here that I have been aware of the following issues for some time but have not thought it appropriate to raise them, in the interests of not giving the opposition a chance to hang their hat onto something that in the context of the standard SL1200 is not a massive problem.

I do hope my friend Arthur is reading this, as it could save him wasting his time!!! This will probably come as a bombshell to all those who follow this website and another one! And to those subscribers to other websites that I no longer have access to! And who have opined about the use of Plastic be it Acrylic or Delrin and whether Museum or Fish grade (Aquarium), with such superlatives as the following:

"Nothing like anything anyone has seen before ( think Clearaudio Statement ) and integrates properly with the direct drive PLL."

I investigated the use of acrylics and other materials before deciding on Aerospace grade Alluminium for the foregoing reason And this is not totally my own theoretical treatise on this subject. Other audiophiles, on other forums, who are devout anti SL1200ers have put forward their own justifications for not embracing the SL1200, based on the following:

Firstly, absolutely no one; out of all the supposedly technical experts who like to contribute their opinions; has given any thought to this: What do you think is bolted to the underside of the platter, a lump of Swiss cheese??

No. it is a very powerful ferrite Isotropic Magnet, Radially magnetised with a large number of poles. I will not say how many, I will leave it to the ‘temperature expert’ genius to see if he can work it out. Yes I do know, and I have plotted the polar fields it produces.

Now, to an extent the very intense flux fields emitted radially outwards and upwards, by the magnetic rotor are shielded by the design of the ‘Direct Drive Magnetic Motor System’ However, in any system such as the SL1200 Direct Drive motor, some flux leakage can and will occur.

However, the SL1200 platter does consist of a 3mm layer of metal albeit most of the mass is made up of bonded rubber! This metal platter has the effect of most definitely and positively screening the cartridge from any flux leakage from the motor magnet. The reason being is that the “permeability’ of Alluminium, which is a paramagnetic material (as opposed to a diamagnetic one) is sufficiently high when compared to air that it does have a considerable flux shielding affect. Copper is even much better!

Acrylic is practically useless in this regard and would be almost equal to air. (would some one out there like to check on this!)

The whole subject of magnetic flux and relative permeability is not the subject for this forum. For those who wish to follow it up I can suggest:
“Electricity and Magnetism” A degree in physics. C J Smith and Arnold. (My edition was 1959)

It follows therefore, does it not, that a platter machined from a solid blank of aluminium 16mm thick and bonded with a 3mm plate of annealed copper is going to be unbelievably vastly superior to a lump of Acrylic, even if Dave Cawley is selling it....!

This flux leakage when interacting with the coil of a good quality sensitive cartridge will result in modulation of the collected signal.
How does this happen. Given that the record and the platter and therefore the Magnet and its magnetic poles are rotating at 33rpm any leakage flux will be cutting the coils of the cartridge, at the rate of the number of poles, which the magnet has, per revolution.

Now here comes the crunch!! If at any particular point in real time the cartridge is transducing a pure note or complex waveform at the point when one of the flux fields of the magnet is cutting the cartridge coils, then presto you a have a fantastic bit of modulation and resultant distortion.

Now here comes the interesting bit, the position of the particular section or fraction of audio that could be affected, in relation to the flux fields of the magnet as they pass under the cartridge, is going to be dependant on the radial position that the record is located onto the platter. In other words any perceived modulation or otherwise distortion, will never be constant or repeatable for evaluation or correction purposes!!! Just a random degradation of the sonic experience predicated on the audio content of any particular record and it’s position as placed onto the platter.

And this is only going to cost you about $800.

As I have stated earlier in this analysis, I have plotted the flux fields and carried out a few simple evaluations of my own, all of which lead me to the conclusion that the use of any non-metallic material is going to greatly but randomly degrade the performance of a direct-drive turntable, such as the SL1200.

Indeed it should be intellectually intuitive to any one who has just the merest modicum of intelligence; that not having some effective flux screening between the powerful magnet and the very sensitive cartridge must surely be asking for problems.

It is I believe, because of the foregoing observations, that the copper mats are so effective on the SL1200 series of turntables. Besides providing extra mass, they provide an order of magnitude higher shielding against any flux leakage that may just occur. Remember we are talking sub-micro volts in the cartridge coils and phono amplifier electronics.

In conclusion I do not believe that the use of acrylic in this instance for a direct drive turn table is a particularly smart one. Sure, it is a lot less costly to produce than my alluminium/copper approach, and is about $100 cheaper to boot!

Some may enquire that almost all the rubber band-driven turntables use some form of acrylic platter. Exactly!! Because the vendors of these units must realize a decent profit to stay alive, and acrylic is dirt cheap compared to aluminium and copper. The motors on these units are high torque AC or DC off-the-shelf units, with adequate shielding, most often this could be Mu-metal (the ultimate flux screening material).

Further, they are usually placed about 500mm from the centre of the platter, far enough away that any flux leakage would never be a problem.

chris@panteg
11-05-2011, 10:37
Hi Mike

I've asked Dave about the screening of the platter , and well , you can see his answer !

I've also asked Richard (Vantage Audio) about this platter and look forward to reading his thought's . FWIW my feeling is the OEM does screen out the magnetic field of the magnet , but i don't regard myself as an expert on this TT , just looking for a straight answer ! And wanting to learn something .

Marco
11-05-2011, 10:51
Hi Chris,


i don't regard myself as an expert on this TT , just looking for a straight answer ! And wanting to learn something .

Indeed.

Trouble is, you'll never get a straight answer from Dave C, simply because his modus operandi is to shroud everything in an air of 'mystique' and secrecy in order to portray the image that his knowledge of the SL-1200 is somehow 'unique', which of course adds to his delusion that he's a Technics T/T 'guru' - and the 'world's leading one', at that...! ;)

Don't ask him too many questions, though, as he'll simply ignore them, or selectively answer some, and eventually trip himself up! When you scratch below the surface and expose his technical naivety, like Mike has just done, however, the truth comes out.

Mike - an excellent post. I'll comment more after lunch :)

Marco.

chris@panteg
11-05-2011, 11:02
Hi Chris,



Indeed.

Trouble is, you'll never get a straight answer from Dave C, simply because his modus operandi is to shroud everything in an air of 'mystique' and secrecy in order to portray the image that his knowledge of the SL-1200 is somehow unique, which of course adds to the delusion that he's a Technics T/T 'guru' - and the 'world's leading one', at that...! ;)

Don't ask him too many questions, though, as he'll simply ignore them, or selectively answer some, but eventually trip himself up! When you scratch below the surface and expose his technical naivety, like Mike has just done, the truth comes out.

Mike - an excellent post. I'll comment more after lunch :)

Marco.

Fortunately for me i do know someone who does understand this TT and i have 100% faith and confidence in the guy :)

Marco
11-05-2011, 11:09
Indeed - Richard does, as does Mike (and I have 100% confidence in him)! ;)

Isn't it funny how I knew what material the new platter was made from before Dave could inform folks on his own forum!!

What does that tell you?

Marco.

Mike_New
11-05-2011, 11:47
Hi Folks,
I should perhaps clarify one point concerning my former evaluation of Acrylic platters. I refer to the poles of the magnet passing the critical point of the cartridge coils. In fact in a radially magnetised toroidal type magnet, the poles are the concentration points of the flux, the radial space between them is where the actual flux density spreads outwards.
As a very simple analogy, try to imagine a simple bar magnet from your school days, and then think of a large number of them arranged into a circle.

JazzBones
11-05-2011, 11:50
Indeed it should be intellectually intuitive to any one who has just the merest modicum of intelligence; that not having some effective flux screening between the powerful magnet and the very sensitive cartridge must surely be asking for problems.

It is I believe, because of the foregoing observations, that the copper mats are so effective on the SL1200 series of turn tables. Besides providing extra mass, they provide an order of magnitude higher shielding against any flux leakage that may just occur.
Remember we are talking sub micro volts in the cartridge coils and phono amplifier electronics.....

Bullseye Mike, you've got it in one mate :clap:

Ron :)

JazzBones
11-05-2011, 16:17
http://img823.imageshack.us/img823/3091/eimg0502.jpg (http://imageshack.us/photo/my-images/823/eimg0502.jpg/)


For me, that looks far nicer and classier than the 1210 pictured on the Timestep forum, shown earlier :)

Marco.

Marco, I have noted, within this forum, that I was not a great fan of Mike New's platter purely on looks alone (never heard a deck with one yet) but looking at your pic above and especially our forum brother in Singapore who posted a collage of his deck with blue lighting I've changed me mind (its my mind and I'm allowed to :) ). A good polish and possibly a professional protective lacquer would definitely be something worth owning. Along side the acrylic (TS) jobby the contest is over. The acrylic is just that, a wee jobby, just flush and hope it doesn't float :eyebrows:

Whilst on the subject of the MN platter did you install the MN strengthening plate on your deck when you did the comparison with Martin T's deck? Just curious? Any plans to do so?
:cheers: Ron

PS Marco is your TT male, coz I can clearly see a little black erection :scratch::lol:

Marco
11-05-2011, 16:44
Hi Mike,

Just to pick up on a few points from what you've written:


I do hope my friend Arthur is reading this, as it could save him wasting his time!!!


I've asked Arthur to comment, and he will do so in due course. I know his answer is sure to be enlightening.......


This will probably come as a bombshell to all those who follow this website and another one! And to those subscribers to other websites that I no longer have access to! And who have opined about the use of Plastic be it Acrylic or Delrin and whether Museum or Fish grade (Aquarium), with such superlatives as the following:

"Nothing like anything anyone has seen before..."

Well that's a typical example of Dave getting rather over-excited in an attempt to be seen as 'the special one'... "Nothing like anyone has seen before?" - You mean an acrylic platter like that used on many other T/Ts currently on the market?

The platter looks nice enough, but I don't see anything radical in its design such as "nothing anyone has seen before". So, as Michael Winner would say: "Calm down, dear!" :lol:


Now, to an extent the very intense flux fields emitted radially outwards and upwards, by the magnetic rotor are shielded by the design of the ‘Direct Drive Magnetic Motor System’ However, in any system such as the SL1200 Direct Drive motor, some flux leakage can and will occur.

However, the SL1200 platter does consist of a 3mm layer of metal albeit most of the mass is made up of bonded rubber! This metal platter has the effect of most definitely and positively screening the cartridge from any flux leakage from the motor magnet. The reason being is that the “permeability’ of Alluminium, which is a paramagnetic material (as opposed to a diamagnetic one) is sufficiently high when compared to air that it does have a considerable flux shielding affect. Copper is even much better!

Acrylic is practically useless in this regard and would be almost equal to air.

It follows therefore, does it not, that a platter machined from a solid blank of alluminium 16mm thick and bonded with a 3mm plate of annealed copper is going to be unbelievably vastly superior to a lump of acrylic.


And:


It is I believe, because of the foregoing observations, that the copper mats are so effective on the SL1200 series of turntables. Besides providing extra mass, they provide an order of magnitude higher shielding against any flux leakage that may just occur.

So my decision to have my own platter bonded with 3mm of annealed copper is vindicated? Nice one! :)

My theory for doing so was based on nullifying the effect of any eddy currents being generated by the motor unit, where in fact the main priority was actually screening the cartridge effectively from any flux leakage from the motor magnet. Or is that in fact one and the same?


This flux leakage when interacting with the coil of a good quality sensitive cartridge will result in modulation of the collected signal.
How does this happen. Given that the record and the platter and therefore the Magnet and its magnetic poles are rotating at 33rpm any leakage flux will be cutting the coils of the cartridge, at the rate of the number of poles, which the magnet has, per revolution.

Now here come the crunch!! If at any particular point in real time the cartridge is transducing a pure note or complex waveform at the point when one of the flux fields of the magnet is cutting the cartridge coils, then presto you a have a fantastic bit of modulation and resultant distortion.


Very interesting.... I wonder if DC, in his infinite wisdom, as the self-confessed Technics T/T guru extraordinaire, had considered those facts?


Now here comes the interesting bit, the position of the particular section or fraction of audio that could be affected, in relation to the flux fields of the magnet as they pass under the cartridge, is going to be dependent on the radial position that the record is located onto the platter.

In other words any perceived modulation or otherwise distortion, will never be constant or repeatable for evaluation or correction purposes!!! Just a random degradation of the sonic experience predicated on the audio content of any particular record and it’s position as placed onto the platter.


Or that one? ;)


As I have stated earlier in this analysis, I have plotted the flux fields and carried out a few simple evaluations of my own, all of which lead me to the conclusion that the use of any non-metallic material is going to greatly but randomly degrade the performance of a Direct Drive Turntable such as the SL1200.

Indeed it should be intellectually intuitive to any one who has just the merest modicum of intelligence; that not having some effective flux screening between the powerful magnet and the very sensitive cartridge must surely be asking for problems.


Yup - even a technical numpty, like me, can understand that!

Do we know, however, if Arthur has fitted any form of shielding, e.g. a copper (or Mu-metal) plate, on the underneath of the acrylic platter?

It's possible, as other than Arthur (and wonder-boy from Dartmouth) I don't think anyone's seen what the underneath of the new acrylic platter looks like.

However, such shielding would simply be acting as a bandage. If acrylic really is the wrong material from which to construct a platter to use on a direct-drive turntable, then any incorporated shielding would simply smack of 'locking the barn door after the horse has bolted'...

Far better not to have let the horse bolt in the first place!! However, knowing Arthur, he must've considered this.......?


Some may enquire that almost all the rubber band-driven turntables use some form of acrylic platter. Exactly!! Because the vendors of these units must realize a decent profit to stay alive, and acrylic is dirt cheap compared to aluminium and copper. The motors on these units are high torque AC or DC off-the-shelf units, with adequate shielding, most often this could be Mu-metal (the ultimate flux screening material).

Further, they are usually placed about 500mm from the centre of the platter, far enough away that any flux leakage would never be a problem.

Ah, now that makes sense! :cool:

Marco.

Marco
11-05-2011, 17:41
Hi Ron,


Marco, I have noted, within this forum, that I was not a great fan of Mike New's platter purely on looks alone (never heard a deck with one yet) but looking at your pic above and especially our forum brother in Singapore who posted a collage of his deck with blue lighting I've changed me mind (its my mind and I'm allowed to). A good polish and possibly a professional protective lacquer would definitely be something worth owning.


Naturally, I agree. I'm afraid that, no matter how cleverly designed or sonically beneficial, I don't find 'frosted plastic' attractive as a platter material. It's just a personal taste thing.

I think the factors that have changed your mind about the look of the MN platter (as I suspect you have similar tastes to me in this respect) are seeing it against the aesthetic backdrop of a MK5, as opposed to a MKII, Techy.

The former is finished, aesthetically, to a superior standard (the very reason I bought one), and its highly polished top-plate compliments a nicely polished MN platter perfectly, particularly I feel when a slither of copper around the periphery of the platter breaks up the slight 'blandness' of the aluminium - wouldn't you agree? :)


Along side the acrylic (TS) jobby the contest is over. The acrylic is just that, a wee jobby, just flush and hope it doesn't float :eyebrows:


:lolsign:

Stop it - you're appealing to my love of toilet humour!


Whilst on the subject of the MN platter did you install the MN strengthening plate on your deck when you did the comparison with Martin T's deck? Just curious? Any plans to do so?


No, I haven't installed the bearing base plate yet, and doubt I will do so. Not because I don't think it's effective in an engineering sense (it is), but I've compared my T/T with Martin's (which has the base plate fitted) and it's very difficult to discern any sonic benefit which would justify the ball-ache required to fit it! ;)


PS Marco is your TT male, coz I can clearly see a little black erection :scratch

Hehehe... Meet 'Mambo' my wee Furutech anti-static brush! :eyebrows:

Marco.

pure sound
11-05-2011, 21:14
If screening is required above this motor it'll be very evident when the TT tries to play unmodulated parts of the record.

Incidentally one of the finest DD turntables, the Goldmund Studio, used a methacrylate platter over the Dual EDS1000 motor without screening or noise issues. Also, if I'm not mistaken, the EMT948 and 950 use non metallic platters over substantial direct mechanisms. They don't have noise issues either. I wouldn't assume this new platter will give problems. It may but it may not.

Alex_UK
11-05-2011, 21:32
Marco - I think a spoonful of your own medicine may be appropriate in these circumstances - theories are all well and good, but ears should be the final and only arbiters - acrylic may indeed not work with the 1200/1210 - but no one will know for sure either way until heard - the proof of the pudding, etc. I'm sure you will tell it as it is, but until such time as the new platter is actually listened too, everything is merely conjecture. For sure, all parties will be beating their chests, and rightly so - but we will only know for sure with a direct comparison. (No offence intended to any party - just telling it how I see it. :))

Marco
11-05-2011, 21:56
Oh, absolutely, chaps. The proof of the pudding is always in the listening, and since Arthur's behind the design of the new platter, you can virtually guarantee it'll be good!

I think we're all just 'thinking out loud' and going through what may or may not happen.

One thing's for certain, and I think you all know me by now, is that when I listen to the acrylic platter on my T/T, I'll simply tell it as I hear it, and if that means it turns out to be better than my Mike New platter, then so be it!!

I love pushing the envelope as far as possible and making new discoveries :)

Marco.

Alex_UK
11-05-2011, 22:05
One thing's for certain, and I think you all know me by now, is that when I listen to the acrylic platter on my T/T, I'll simply tell it as I hear it, and if that means it turns out to be better than my Mike New platter, then so be it!!

Never in doubt, dude. :) I'm looking forward to seeing how it all pans out. :popcorn:

chris@panteg
12-05-2011, 10:07
Hi Folks,
I should perhaps clarify one point concerning my former evaluation of Acrylic platters. I refer to the poles of the magnet passing the critical point of the cartridge coils. In fact in a radially magnetised toroidal type magnet, the poles are the concentration points of the flux, the radial space between them is where the actual flux density spreads outwards.
As a very simple analogy, try to imagine a simple bar magnet from your school days, and then think of a large number of them arranged into a circle.

Hello Mike

A couple of question's for you if that's ok .


How does the Technics magnet function then? and ...


What sort of flux pattern do you actually get using the Technics magnet (with or without the platter)?

MCRU
12-05-2011, 10:15
Hey marco the marvellous, can I borrow your MN platter whilst you give Arthur's new platter some serious listening time?

Go on, you know you want to.

http://theartofsound.net/forum/../images/smilies/7002.gif

Marco
12-05-2011, 13:40
Lol - how am supposed to compare the two platters against each other, if you've got one of them? ;)

It'll be 3-4 weeks before I get the acrylic platter, anyway, dude. Once the comparisons are over and done with, yes, you can borrow my MN one, provided you get a bigger power supply to take it...

Remember, you need a Paul Hynes SR3, SR5, or Timestep SE, before you can use an MN platter, and TBH, a better bearing than the stock one (Vantage Audio or MN) :)

Marco.

MCRU
12-05-2011, 13:43
I have a better bearing thanks and a chunk of metal rotating at 45rpm for 15-20 mins. will not need a better PSU, I only need to listen to my favourite 12" singles to see if I want to buy one. The audition will be done within 1/2 an hour and findings reported upon.

Nice one.

Oh I forgot to mention besides my very own design of platter which I will be launching soon I will also be looking into building a PSU.

Marco
12-05-2011, 13:47
Half an hour's auditioning? Lol - you're a right thorough bastard, eh!! :lol:

Have you got an MN bearing? If so, I didn't know.

Your Techy will sound pish with the MN platter fitted, if you use it with a PSU which can't handle the extra mass. It affects the speed stability of the T/T (making it sound soft and woolly) whether it's for 15-20 mins or 0.5 secs!

Best plan is for me to bring the platter round, along my SR5 PSU, and fit both to your T/T, and let you hear it that way :cool:

Marco.

MCRU
12-05-2011, 13:53
By the time you send me the platter I will have a PSU built and in place so don't concern yourself with trivialities.

Don't forget to send my Bollinger for services rendered.

http://theartofsound.net/forum/../images/smilies/HandClap.gif

Marco
12-05-2011, 14:01
:lolsign:

Let me know then when you've built your PSU, and we'll take it from there!

Marco.

MCRU
12-05-2011, 14:08
NO, NO, NO

The PSU is a 2 minute job so don't delay, 4 weeks from now is 09.06.11, it is in my diary already.

Mike_New
12-05-2011, 23:44
Hello Dave,

[QUOTE=Mains Cables R Us;214005]

"I have a better bearing thanks and a chunk of metal rotating at 45rpm for 15-20 mins. will not need a better PSU, I only need to listen to my favourite 12" singles to see if I want to buy one. The audition will be done within 1/2 an hour and findings reported upon."

With all due respects Old fellow I really do not think you know what you are bloody well talking about.
The increase in sonic quality does not operate on a time frame such that for the first "15-20mins" you can magically assess the quality of my "chunk of metal (nea my Quality solid alluminium and bonded copper platter)" whilst using an inferior bearing and power supply. And to boot you offer to publish your findings. God help us!!! but he probably can't save us from some people!!!!

Marco was absolute correct in his sage advice to you.

Mike_New
13-05-2011, 00:30
Hi Chris

Hello Mike

A couple of question's for you if that's ok .


How does the Technics magnet function then? and ...


What sort of flux pattern do you actually get using the Technics magnet (with or without the platter)?

The Technics magnet functions in the same way that all magnets do when interacting with another magnetic field (flux) generated by driving coils.
The secret is in the way Technics have designed what is known as a isotropic radially poled magnet, the many poles of which are designed to be synchronously acted upon by the twelve stationary coils. Which in turn, are synchronously switched by the position rotor. In fact the slightest incorrect positioning of this rotor on the platter can actually cause the platter to rotate in reverse, or worse still, not to perform correctly in the forward direction.

The flux pattern is a radial one as explained previously, In simple terms it’s strength, at any point in space, will be moderated by any material that may be placed in the path of the flux field. For instance the flux field from the OEM transformer of the SL1200, is shielded in a crude way, by what I believe may be Mu metal sheets place around the transformer.

It is very interesting, since posting my first observations on this subject I have carried out some simple tests on my Benz Ruby MC. This cartridge has a hugely powerful ‘rare earth’ type of permanent magnet; as indeed do all other quality MCs.

Now I will leave you to speculate on what the results could, be when the field of theses very powerful, but small MC magnets, come into reaction range of another magnetic flux field, especially a rotating one!!!!!

I will post a description of my thoughts on this, if people are still interested.

chris@panteg
13-05-2011, 01:25
Hi Chris


The Technics magnet functions in the same way that all magnets do when interacting with another magnetic field (flux) generated by driving coils.
The secret is in the way Technics have designed what is known as a isotropic radially poled magnet, the many poles of which are designed to be synchronously acted upon by the twelve stationary coils. Which in turn, are synchronously switched by the position rotor. In fact the slightest incorrect positioning of this rotor on the platter can actually cause the platter to rotate in reverse, or worse still, not to perform correctly in the forward direction.

The flux pattern is a radial one as explained previously, In simple terms it’s strength, at any point in space, will be moderated by any material that may be placed in the path of the flux field. For instance the flux field from the OEM transformer of the SL1200, is shielded in a crude way, by what I believe may be Mu metal sheets place around the transformer.

It is very interesting, since posting my first observations on this subject I have carried out some simple tests on my Benz Ruby MC. This cartridge has a hugely powerful ‘rare earth’ type of permanent magnet; as indeed do all other quality MCs.

Now I will leave you to speculate on what the results could, be when the field of theses very powerful, but small MC magnets, come into reaction range of another magnetic flux field, especially a rotating one!!!!!

I will post a description of my thoughts on this, if people are still interested.

Thanks Mike

The OEM transformer is indeed shielded by Mu metal , this along with Richard's explanation as to how the Technics magnet works and i can quote him .

The ring rotor used in the Technics was designed to focus all flux patterns to the inside circumferance of the ring. There is a very simple test you can do to see this in action. Take a metal screwdriver blade and present it to the outer surface of the rotor ring. Do the same from the top and lower edge. Now present the blade to the inner circumfernace of the rotor (be careful here as you do not want a sudden shock impact of the blade against the ring in case you "chip" the ring. Just use a wee bit of sense here and retain a firm grip on the blade). What result do you find?


Remember basic physics and flux patterns in ring magnets. Most times flux leakage is associated with "air gaps" and is put to good use in loudspeaker drive units. The idea of a ring magnet is just that - direct the flux pattern where you want it. Look at the flux patterns for a ring magnet and you will see the pattern concentrated on the horizontal axis and any vertical axis flux pattern will be introduced via an air gap on the open face.

Mike_New
13-05-2011, 03:10
Hi Chris


Thanks Mike

The OEM transformer is indeed shielded by Mu metal , this along with Richard's explanation as to how the Technics magnet works and i can quote him .

The ring rotor used in the Technics was designed to focus all flux patterns to the inside circumferance of the ring. There is a very simple test you can do to see this in action. Take a metal screwdriver blade and present it to the outer surface of the rotor ring. Do the same from the top and lower edge. Now present the blade to the inner circumfernace of the rotor (be careful here as you do not want a sudden shock impact of the blade against the ring in case you "chip" the ring. Just use a wee bit of sense here and retain a firm grip on the blade). What result do you find?


Remember basic physics and flux patterns in ring magnets. Most times flux leakage is associated with "air gaps" and is put to good use in loudspeaker drive units. The idea of a ring magnet is just that - direct the flux pattern where you want it. Look at the flux patterns for a ring magnet and you will see the pattern concentrated on the horizontal axis and any vertical axis flux pattern will be introduced via an air gap on the open face.

If we are not careful this discussion is going to get awfully complicated and theoretical.

Indeed the main magnetic flux is concentrated inside the rotor ring. And yes Richard is correct when he observes that the major magnetic force as observed with the crude device of a screwdriver is on the inside of the torus, which is where the reaction of the driver coils operate to drive the magnet around it’s axis.

However he seems to miss the point! There is a flux field on the outer periphery of the rotor, for the simple reason that it is not possible to totally constrain all the magnetic flux in the ideal way, which we would wish, when magnetizing a virgin ferrite ring. This outer peripheral flux can be regarded as leakage if you wish.

Flux leakage has nothing to do with air gaps, and it certainly is not flux leakage that drives motors, quite the opposite!
In fact by definition 'Flux Leakage" is the stuff we do not want!!!


When Richard talks about his basic physics, he does not seem to have any understanding of the fact that the "air Gap" generates the electromotive force; the power is transmitted across the air gap! One of the fundamental facts of nature that is not even today, fully understood. Flux fields do not require an "Air Gap" per se' to exist, rather they can occur wherever there is an unshielded "air space'. By definition, one normally refers to the "Air Gap" as being the space in which the magnetic flux is constrained to produce the power.


When he talks of loud speaker drive units, these are nothing more than basic linear motors operating within an air gap.

When I refer to flux leakage, I am referring to any and all, magnetic fields that are present where we do not want them, and which can be detrimental to the performance of the “system” unless adequate attention is accorded to shielding. Think “HUM” and consider how difficult this can be to constrain, after all it is only the magnetic flux generated around a simple wire by the flow of electrons.

All I am saying is that there is a powerful magnet bolted to the underside of the platter, and however well designed it might be, there will most certainly be a magnetic field of some sort. It is surely prudent for us to consider this when we talk about platter materials.

Marco
13-05-2011, 07:53
If we are not careful this discussion is going to get awfully complicated and theoretical.


Indeed...

Whilst this is all very interesting, up to a point (as far as anyone here can understand the technical nature of what is being written), I don't think we should be having discussions based on information relayed from emails by non-members.

Whilst I value Richard's opinions, if he wishes to engage Mike in debate on the matter of platters, then he should go through the normal channels and register here as a member, whereby he can then contribute to the discussion properly.

Richard always seems to have plenty to say (much of which I agree with), so I've never understood why he restricts his comments to emails, and shuns the opportunity to express his views on the forum.

Marco.

MCRU
13-05-2011, 08:15
mike :)
go take a chill pill, its a turntable platter, hardly a life or death issue is it boss?

as regards time frame to hear the sonic difference of your goods, are you saying there is a burn in period for a platter and bearing?

so is it at it's optimum performance threshold after a set period of time?

if its so fantastic surely I would hear the improvement after 5 minutes?

BTW you don not know what bearing and PSU I have in the house and how do you know it's inferior to yours if you don't know which one it is?

:ner::ner::ner::ner::ner::ner::ner::ner::ner::ner: :ner::ner::ner::ner::ner:

Marco
13-05-2011, 08:18
Lol - so which bearing have you got, then daftee? I did ask you before, and now I'd like to know :)

Marco.

MCRU
13-05-2011, 08:22
The Technics has been dis-mantled and sold for spare parts, end of. I am now looking for a forum where I can have a rational discussion about Garrards without being insulted. :violin::booty:

Marco
13-05-2011, 08:25
Lol - aye, very good!!

Marco.

chris@panteg
15-05-2011, 00:27
Indeed...

Whilst this is all very interesting, up to a point (as far as anyone here can understand the technical nature of what is being written), I don't think we should be having discussions based on information relayed from emails by non-members.

Whilst I value Richard's opinions, if he wishes to engage Mike in debate on the matter of platters, then he should go through the normal channels and register here as a member, whereby he can then contribute to the discussion properly.

Richard always seems to have plenty to say (much of which I agree with), so I've never understood why he restricts his comments to emails, and shuns the opportunity to express his views on the forum.

Marco.

Hi Marco

To clarify , Richard didn't ask his views to be posted on this forum ! I simply asked him how he believes the Technics magnet works , I also asked his permission to post this explanation , and if this breaks forum rules and ethos , then the fault is mine entirely ! I just thought it was important enough in this instance .

But also to add that as this new platter is all Arthur's work , then I'm rather persuaded that he must have looked at the possibility of any magnetic flux leakage and found it not to be a problem ? Perhaps Arthur could elaborate .

One other thing to add is that Richard's own choice of platter is an alloy one bonded with copper plate ! Either the OEM modified or a bespoke platter.

Marco
15-05-2011, 00:46
Hi Chris,


To clarify , Richard didn't ask his views to be posted on this forum !


No, I know, but they often end up here anyway, via you! ;)


I simply asked him how he believes the Technics magnet works , I also asked his permission to post this explanation , and if this breaks forum rules and ethos , then the fault is mine entirely ! I just thought it was important enough in this instance .


No rules broken, dude, but I'd rather that any views being expressed on this subject (and discussed) were those belonging to members of AoS, otherwise it gets a little ridiculous.


But also to add that as this new platter is all Arthur's work , then I'm rather persuaded that he must have looked at the possibility of any magnetic flux leakage and found it not to be a problem ? Perhaps Arthur could elaborate .


I've asked him, so he will comment in due course. Right now he's loaded with the flu.


One other thing to add is that Richard's own choice of platter is an alloy one bonded with copper plate !

:eyebrows:

Marco.

chris@panteg
15-05-2011, 00:58
Hi Chris,



No, I know, but they often end up here anyway, via you! ;)




Marco.

Yes , then slag me off not Richard !

Marco
15-05-2011, 01:00
Lol - I'm not "slagging off" anyone! Where did you get that idea from?

Marco.

Mike_New
15-05-2011, 02:37
Hi Chris,
I believe in fact Richard has one of my platters.

Marco
15-05-2011, 02:41
Most interesting....! ;)

Marco.

YNWaN
15-05-2011, 07:51
I will post a description of my thoughts on this, if people are still interested.

Yes please.

chris@panteg
15-05-2011, 10:49
Lol - I'm not "slagging off" anyone! Where did you get that idea from?

Marco.

My Mistake , I was incredibly pissed last night , when i wrote that :)

I shouldn't really blame the drink though .

chris@panteg
15-05-2011, 10:53
Hi Chris,
I believe in fact Richard has one of my platters.

Hi Mike

I believe he has , he knows it well .

Marco
15-05-2011, 10:53
My Mistake , I was incredibly pissed last night , when i wrote that

I shouldn't really blame the drink though.


Lol - don't worry about it, mate. We're all human! Hope your head isn't too sore this morning ;)

Marco.

chris@panteg
15-05-2011, 10:56
Lol - don't worry about it, mate. We're all human! Hope your head isn't too sore this morning ;)

Marco.

Thanks , no too bad , just a little delicate ;)

It was Everards Tiger :) and some excellent live music .

chris@panteg
15-05-2011, 17:27
Hi Mike

I believe he has , he knows it well .

Mike , do you mean Richard (Sonddek) ?

Rare Bird
15-05-2011, 17:56
My Mistake , I was incredibly pissed last night , when i wrote that :)

I shouldn't really blame the drink though .

Why not i do :lolsign:

chris@panteg
15-05-2011, 23:40
Why not i do :lolsign:

"In Vino Veritas" But not always lol , sometimes just gibberish . :)

FunkArt
17-05-2011, 19:09
With the platter still in prototype form, I had wanted to leave commenting till much closer to release but sufficient has been written encouraging an early response.

“Direct drive “turntables””.
“Paramagnetism(?)” (as opposed to diamegnetism, as opposed to ferromagnetism).
Lexan (polycarbonate) vs acrylic.
Flux leakage.
These and more have been introduced as potentially problematic.
The following thoughts are intended to help.

Let’s start with the DD turntable: This is but a motor with its attached load - we might call it a platter, (plastic, aluminium etc.) but it is just a load.

Now, at below £500 lest we forget, SL1200 was built to a price. People buy it because it is a value-for-money entry product.
it succeeds only because the size of its highly refined motor permits a high torque. This is SL1200’s true claim to fame.

Why entry product? For high end use its other features are mediocre - else why the need for a new arm, platter, isolation and so on?
Once upgraded, however, there is no doubting SL1200’s renewed capabilities but then all that’s left of the original is the motor!
But even the execution of the motor is left wanting…

Motor Design:
For a motor to work, there must be an associated magnetic field [sic].
SL1200’s drive coils are all but totally enclosed in the magnet’s rotor, with virtually no leakage. So, no adverse effects result from them.
Eddy currents: These occur only in metals subjected to a varying magnetic field.
SL1200’s platter and rotor magnet are one - they turn together - thus, no eddy currents are generated in the platter.

If a motor is shielded, then it is shielded. End of discussion.
If, however, a motor is unshielded, its magnetic field spreads out. SL1200’s rotor is not fully shielded; flux leakage is defacto.
Aluminium (“paramagnetic” or otherwise), can’t shield magnetic fields, which are actually detected through the platter at the record. This holds equally for copper.
We plot and measure field strength using Hall sensors but few of us have those in our kitchen drawers. Still, this field is high enough for a simple child’s compass to detect! Now, this is something you can all try with your aluminium platters.
It gets worse. The alternating poles of the rotor’s magnet produces an alternating field. This is close to the end of side but its interaction with cartridges is not easy to predict given different cartridge sensitivities and designs. What is certain is that this not what we want from a high end product. It must be dealt with accordingly.
This is one reason (of two) why using just a mat is not a full solution. Needless to say, eliminating this was part of the design brief.
(Given the nature of the problem, (we didn’t design the motor) it is churlish to regard this as a case of shutting the stable door after the horse has bolted. Still, given the era SL1200 was developed it was a masterful piece of engineering. Respek.)

To recap: As the platter moves with the magnet, there is no mechanism for eddy currents to be generated; so it matters little if the platter is aluminium, acrylic or Swiss cheese (Everyone knows Swiss cheese makes poor magnets).
Flux does, however, escape from rotor’s magnet. Unshielded it induces voltages in the sensitive generator of cartridges, requiring of a solution.

Platter material choice:
Both Lexan and acrylic have indeed been considered with Lexan pushing up the price considerably.
“But we are not price sensitive, here. Surely it is performance that matters?” I hear you ask. (Not price sensitive? Hmmm)
“Subtle but important”, (as quoted), Lexan may better acrylic but
under test, where our tests went further and ignoring Lexan’s elevated price, we concluded that adding (the modestly priced) Achromat improved on Lexan. (As we believed it ought to).
Why go all out to screw punters with a more expensive platter that could then itself be further improved?
Made no sense to us. We stuck with acrylic.
(Save the difference towards our arm and get yet more improvement!)

In conclusion, the raison d’etre of our platter:
- To produce a more stable platform mechanically than SL1200’s original offering, which rings.
Well, our one does not ring. ✔

- To eliminate any flux leakage that might otherwise interfere with the cartridge’s function.
Well our compass no longer moves. ✔

- 1200’s have excellent overshoot characteristics. We retained this by optimising various of the platter’s dimensions to match the inertial load, motor power and servo. (Increase mass / inertia willy nilly and stability is adversely affected. It’ll work but not as designed.)
If this is a bit techy, you’ll just have to trust us. ✔

- To produce an overall improvement in performance for a reasonable price given all the various and conflicting demands.
Any high end deck+ arm will set you back £5-15k. Fully laden mods are less than £3k. And the results…
The proof is in the listening. ✔


Simples. Bzchuz

Well, back to work.

Arthur

MCRU
17-05-2011, 19:32
5 posts in 3+ years, well the above was certainly worth waiting for! :)

Nice write up kind sir.

chris@panteg
17-05-2011, 21:17
Thanks for talking the time out to explain , Arthur ! I think a few question's have been answered .

Marco
17-05-2011, 21:36
Most interesting, Arthur. I thought you may have had a plan up your sleeve ;)

Let's see what Mike has to say in response....

For me, though, it's very simple: all the technical postulating in the world means next to bugger all to potential customers (audio enthusiasts) who will buy the product. With hi-fi equipment and ancillaries, the proof of the pudding is always in the listening, so when I receive an acrylic platter to test against Mike's, we shall let 'battle' commence! :eyebrows:

Look out folks for an exclusive in-depth review soon!

Marco.

FunkArt
18-05-2011, 03:50
I couldn't agree more about listening proof being the final arbiter.

Where I'm at really isn't a case of technical high falootedness(?), it is simply being transparent in stating the design process whereby a product starts it journey to reach the real world market.

Designers have preferred routes to a given goal and they should all be respected, all the more once one understands reasons for choices, sometimes difficult, sometimes not always clear that have to be made.

It is a matter of confidence that you the listener are being treated with respect.

In thanking you for your comments, I'm sorry that I find it so difficult to engage more. It's not personal!

Dog walkie time...

Arthur

Marco
18-05-2011, 08:51
Designers have preferred routes to a given goal and they should all be respected, all the more once one understands reasons for choices, sometimes difficult, sometimes not always clear that have to be made.


I absolutely agree, Arthur. If I were to predict anything about the forthcoming comparison between both platters, it would be that neither is likely to be 'superior' overall. However, we shall see.

My suspicion though is that this modification will be subject to achieving synergy with the existing ancillary items on a modified SL-1200/1210, the same as any others to date, and in that respect, choice for each individual will depend on a number of factors. And choice is indeed good!

It is, after all, about marrying the respective sonic signatures of the component parts of the turntable, in order to create a 'musical whole', which is precisely how I build not only my version of a modified Techy, but also my whole system - and therefore there are many variables to consider :)

As I'm sure you'll agree, one must look at modifying the Technics in terms of creating a system, and not merely a collection of disparate parts.

There is one key variable, however, I feel which could heavily influence the outcome of comparisons between platters, and that is which off-board power supply the respective T/Ts being tested are using. In my experience, upgrading the existing PSU on an SL-1200/1210 has the single most significant impact on its sonic performance, closely followed by the bearing and platter, as essentially all heavily influence the behaviour of the drive system.

As you know, there are now quite a few different off-board PSUs on the market for the Technics, all of which will impose their own 'character' on the final sound (or cause the T/T to 'behave' in a certain way, sonically) - and it is the success of this 'relationship' between the PSU and chosen platter, symbiotic or otherwise, that I feel will be highly significant, not to mention the effect of the bearings used (depending on their design), which will also be very influential.

There are, as far as I know, four types of bearing currently to choose from: the stock Technics one, the Timestep one, the Vantage Audio one, and Mike New's - all of which to varying degrees impose their mechanical influence on the sonic performance of the T/T.

A holistic™ approach (descriptive term copyright of Dave Cawley ;)), as ever, will be key to achieving the desired result, and with it, superlative sonic performance.

In that respect, may I ask which PSU and bearing were used on your sample T/T to carry out the preliminary tests with the new acrylic platter?

Marco.

etphonehome
18-05-2011, 13:33
This thread has been a truly interesting read and am thankful to both Mike and Arthur for their contributions explaining the magnetic flux from the Techie motor.

Out of curiosity, I decided to do a simple test with my simple compass.

I took off the MN platter, and held the compass near the motor coil, and when I pressed on the start button, the needle moved and pointed straight at the direction of the coil. Did this a few times and the results were the same.

Then I placed the MN Platter on and did the same, and held the compass at the same position. The needle stayed put.

Now, of course this is a simple crude test at best with a not so sensitive compass...but the platter seems to provide some shielding. How much shielding, I can't say. Will leave it to the experts to do the testing.

FunkArt
18-05-2011, 13:42
In that respect, may I ask which PSU and bearing were used on your sample T/T to carry out the preliminary tests with the new acrylic platter?


Ah. You do like your cans of worms. Well, Marco, from what you have said regarding the importance of the various offerings, it is important to us that what we have is as universal as possible to the majority of readers.

So for simplicity (and consistency) we most often use a standard Techy. Little point talking about something that the vast majority of people do not have (at this stage) and so cannot relate to.

That is not to say that for our own in-house R&D we don't test various other options.
Equally for interest sake it is not too surprising that for example we use FXR in not one but two guises, Rega based and also Techy based. But then we also use more conventional arms, to check for applicability.

There are also other items currently in experimental stage which further extends our overall test procedure but these I can't divulge.

People have commented that it is "only an acrylic platter". Truth be told, this "simple" platter is proving a veritable project in its own right and here's why:
A case in point is the critical central sensor (which comes with the platter). Production of this one apparently straightforward looking component alone comprises some 13 parts and two jigs.

Then there is the testing and measuring parameters of the shield. All necessary iterations in getting it to work invisibly.

It is for all these reasons that although word is out and prototypes have had their initial airing, we are not rushing them out of the door and instead still quoting some 8-10 weeks to production release.

At the end of the day, if, as Marco says, the proof is in the listening and you do end up liking it, there has to be a reason. I'd like to think that all these hours of physics and development played some little part, as they have with other products I have had a hand in creating.

Cheers.

Arthur

Mike_New
18-05-2011, 13:42
Well I guess I should respond to the observations of Arthur in hopefully a non controversial way.

Firstly he discuses the general commercial aspects of the ubiquitous SL1200 series of TTs; which has been well covered and discussed in many posts on this forum and many others. He then goes on at long length to talk about the motor design. Non of which I have any argument with. Excepting that it is interesting to note and I quote:

“If, however, a motor is unshielded, its magnetic field spreads out. SL1200’s rotor is not fully shielded; flux leakage is defacto.”
He then goes on to say, and I quote:

“Aluminium (“paramagnetic” or otherwise), can’t shield magnetic fields, which are actually detected through the platter at the record. This holds equally for copper.
We plot and measure field strength using Hall sensors but few of us have those in our kitchen drawers. Still, this field is high enough for a simple child’s compass to detect! Now, this is something you can all try with your aluminium platters.”

A compass does indeed detect magnetic fields.
And it might be possible to see a deflection when placed on a Solid Copper Bonded Alluminium Platter (I have not tried this yet, I lost my play compass a long time ago) But, then try doing the same thing on an Acrylic platter that does not have some form of shielding attached to it, and see the difference!!!!!!!

You say
“The alternating poles of the rotor’s magnet produces an alternating field. This is close to the end of side but its interaction with cartridges is not easy to predict given different cartridge sensitivities and designs. What is certain is that this not what we want from a high end product. It must be dealt with accordingly”

I would like to clarify the wording here, I believe what Arthur means here is that the flux radiates from the outer edge of the rotor torus. Which is correct, I have plotted it.
Further I would like to mention that the flux intensity like all electromagnetic radiation, is proportional to D^2
Where D is the point distance from the source.
So the real effects of stray flux, will be observed towards the centre of the platter.
It is interesting that Technics, in their infinite wisdom did not make the rotor magnet any larger in diameter that the size of the record label. Maybe they knew something!

Accordingly I ask how does he intend to deal with it??????

Referring to the motor he states:

“Still, given the era SL1200 was developed it was a masterful piece of engineering. Respek.)” (sic)

I agree with him, as I have said on a number of occasions.

His final statement is as follows:

“To recap: As the platter moves with the magnet, there is no mechanism for eddy currents to be generated; so it matters little if the platter is aluminium, acrylic or Swiss cheese (Everyone knows Swiss cheese makes poor magnets). (I personally love a lump of Swiss cheese with a good red) Flux does, however, escape from rotor’s magnet. Unshielded it induces voltages in the sensitive generator of cartridges, requiring of a solution.”
I have never talked about eddy currents, I have always referred my concerns to any stray flux that could cause problems!!

Finally Arthur states that:
“Flux does, however, escape from rotor’s magnet. Unshielded it induces voltages in the sensitive generator of cartridges, requiring of a solution.”

My guess is that Arthur will need to shield the platter underneath by incorporating probably a Mu metal plate, which is very effective at shielding for flux. Technics use it to shield their transformer.
Alluminium and copper do have a shielding and flux defusing effect when they are interpose between a flux source and an interactive element such as another magnet or a coil. Albeit less than Mu-metal, which is the ultimate. In fact Mu metal does contain about 5% of copper ( although the copper may be added for ductility), the rest being nickel and Iron, having a relative permeability of about 100,000 compared to 2,000 for steel.

In conclusion, I have recently been active in pursuing the production of an Acrylic platter, mainly for my own interest.
And to my surprise; I found that a 25mm slab of Acrylic 330mm square only costs $54.20 !!! (In the UK it would be less.)
About 30 pounds in UK money!!! and how much is this platter going to cost??

So what are we talking about here, when we say:

“Why go all out to screw punters with a more expensive platter that could then itself be further improved?
Made no sense to us. We stuck with acrylic.
(Save the difference towards our arm and get yet more improvement!)”

And finally:

“1200’s have excellent overshoot characteristics. We retained this by optimising various of the platter’s dimensions to match the inertial load, motor power and servo. (Increase mass / inertia willy nilly and stability is adversely affected. It’ll work but not as designed.)”

“dimensions to match the inertial load,” I rather think there could be an appropriate response to that!! (Something about the exhaust end of a Bull) But I will not go there. Arthur should really know better, but then I know he does!!!

Finally a quote from the Time Step web site from the man himself:

“I have used several German turntables and realised that nothing beats a solid aluminium platter for ultimate sound quality and stability. But an Acoustic Solid Royal turntable costs nearly £8K without an arm and it still doesn't have the pitch stability of a direct drive.”

http://www.time-step.net/showthread.php?7-Timestep-SL-1200-SL-1210-Platter

So, who are we kidding???

Mike_New
18-05-2011, 14:02
Hi Ernest,


This thread has been a truly interesting read and am thankful to both Mike and Arthur for their contributions explaining the magnetic flux from the Techie motor.

Out of curiosity, I decided to do a simple test with my simple compass.

I took off the MN platter, and held the compass near the motor coil, and when I pressed on the start button, the needle moved and pointed straight at the direction of the coil. Did this a few times and the results were the same.

Then I placed the MN Platter on and did the same, and held the compass at the same position. The needle stayed put.
Now, of course this is a simple crude test at best with a not so sensitive compass...but the platter seems to provide some shielding. How much shielding, I can't say. Will leave it to the experts to do the testing.

Thank you for doing that test for me, I did not read your post before replying to Arthurs, as sometimes down under we seem to get out of sync with the UK.

MCRU
18-05-2011, 14:28
Marco,
On the subject of PSU's mentioned in your post above, by the time you have Arthur's platter I will make sure you also have my new PSU for the Technics so you can do some serious auditioning of various combinations.

It even has kimber cable attached.

Mike_New
18-05-2011, 14:34
Hi Arthur,


There are also other items currently in experimental stage which further extends our overall test procedure but these I can't divulge.

People have commented that it is "only an acrylic platter". Truth be told, this "simple" platter is proving a veritable project in its own right and here's why:
A case in point is the critical central sensor (which comes with the platter). Production of this one apparently straightforward looking component alone comprises some 13 parts and two jigs. Then there is the testing and measuring parameters of the shield. All necessary iterations in getting it to work invisibly.

It is for all these reasons that although word is out and prototypes have had their initial airing, we are not rushing them out of the door and instead still quoting some 8-10 weeks to production release.

At the end of the day, if, as Marco says, the proof is in the listening and you do end up liking it, there has to be a reason. I'd like to think that all these hours of physics and development played some little part, as they have with other products I have had a hand in creating.

Cheers.

Arthur

With all due respects, I worked out the parameters for the "central critical position sensor" (as you put it) nearly two years ago!! And have been making them for my platters ever since. You really only require 8 laminations and a retaining frame.

What is taking you so long? Or are you having other problems that are not as easy as they first looked.....?

MCRU
18-05-2011, 14:41
http://i622.photobucket.com/albums/tt309/themainsman/fighting.jpg

Marco
18-05-2011, 14:46
Hi Mike,

I will comment more later on the recent posts, but I just wanted to address this:


Finally a quote from the Time Step web site from the man himself:

“I have used several German turntables and realised that nothing beats a solid aluminium platter for ultimate sound quality and stability. But an Acoustic Solid Royal turntable costs nearly £8K without an arm and it still doesn't have the pitch stability of a direct drive.”

http://www.time-step.net/showthread.php?7-Timestep-SL-1200-SL-1210-Platter

So, who are we kidding???

Lol - I wonder if Dave C had forgotten he'd written that? Not only the bit you've quoted, but the whole lot is a written endorsement of YOUR platter design and nothing to do with the acrylic one, designed by Arthur, he's currently championing!

I suspect that some frantic editing and/or deletion of that thread will be forthcoming, sooner rather than later... ;)

Amusing though, that you should highlight it for our attention now. I've saved it for reference - nice one! :eyebrows:

Laters,
Marco.

Mike_New
18-05-2011, 15:13
Hi Marco,
So have I!!

Marco
18-05-2011, 15:15
Hi Ernest,


This thread has been a truly interesting read and am thankful to both Mike and Arthur for their contributions explaining the magnetic flux from the Techie motor.


Thanks for your support. AoS is the true home of the dedicated Techy enthusiast, and the only place on the 'net where comprehensive, up-to-date and commercially unbiased information exists on modifying the SL-1200.

Therefore, this thread (and others on here) acts as an accurate resource of information for all those who are interested in modifying the SL-1200/1210 to become a truly world-class turntable, and wish to form their own opinion on how to do so, based on the information presented by those whose opinions matter most: the designers of the products themselves, and crucially, the serious enthusisasts who have direct experience of using the products, where other sites with similar intentions, but commerical interests to protect, flatter to deceive.....

David,


On the subject of PSU's mentioned in your post above, by the time you have Arthur's platter I will make sure you also have my new PSU for the Technics so you can do some serious auditioning of various combinations.


Nice one. I'll be interesting popping that one into the mix! :cool:

And we've still got Anthony TD's multiple regulated PSU design for the Techy to come, which I can tell you is going to be something else.... ;)

Fun times are ahead, folks!

Right, must run off and do a few things - more later.

Marco.

DSJR
18-05-2011, 15:19
May I politely suggest to owners of the MN bearing who wish to try this acrylic based platter that the MN bearing introduces some drag not evident in the stock bearing? The MN bearing was designed for heavier platters such as the one that goes with it and may not work so well with a lightweight affair, which will also give totally different loading to the motor electronics I suspect, although it could be argued that when using the stock platter improved things, this won't matter. These things alone alone may be audible..

Marco
18-05-2011, 15:32
Good point, Dave! Ok, must run.....

Marco.

Marco
18-05-2011, 19:31
Hi Arthur,


Ah. You do like your cans of worms. Well, Marco, from what you have said regarding the importance of the various offerings, it is important to us that what we have is as universal as possible to the majority of readers.

So for simplicity (and consistency) we most often use a standard Techy. Little point talking about something that the vast majority of people do not have (at this stage) and so cannot relate to.


I like cans of worms? Lol - no, not really. I just like to get everything out into the open, and discussed, which is relevant to all those interested in the subject. We don't hide behind shrouds of mystery here, like some others I could mention ;)

So all your testing with the acrylic platter has been carried out with a stock Techy? Interesting......... I presumed that because you were working with 'wonder-boy' from Dartmouth, you'd have used a Timestep bearing and PSU.

Regarding the bit I've highlighted in bold, that's fair enough, but why should those you refer to consider upgrading the platter before, say, the PSU? Novices are unlikely to grasp the importance of a platter upgrade, especially when it's going to cost £600.

And for others, upgrading the platter first would be a rather odd course of action, would it not, considering that the stock PSU is one of the biggest limiting factors of an unmodified SL-1200, and can be upgraded for much less than £600?

I could bring the old horse > bolt > door analogy into the equation again, but I won't.....

In my experience, those who are interested in modifying the Techy to a serious level (beyond attending to relatively superficial items, such as the mat and support feet) tend to go for a PSU or tonearm upgrade first, long before they will consider doing anything with the platter....

Therefore I presume that you've looked at the bigger picture, and so have plans at some point to introduce your own PSU (and perhaps bearing) which compliment the sonic characteristics of your acrylic platter?

Knowing you quite well, and how thorough and how much of a perfectionist you are, I'm certain that will be the case. As I'm sure you'll agree, it's critical that such modifications are carried out holistically, as a system.

In fact, in that respect, whilst I'm obviously keen to hear what the acrylic platter sounds like on my own T/T, I'm beginning to wonder just how relevant my findings will be, based on the fact that my T/T has been judiciously modified with a specific sonic goal in mind, and as such contains products complimentary to achieving that goal, which may not harmonise with 'alien' items introduced into the chain, intended to have a different effect.

But let's do it anyway, as I'm sure it'll be fun and most certainly informative! :cool:

Marco.

Marco
18-05-2011, 22:41
I have also noticed that Dave C (on his forum) has tried to backtrack on his eulogising only last year of the efficacy of the MN platter....

Well of course everyone is entitled to change their mind or move on, but when you make very carefully considered (and rather impassioned) definitive statements such as this:


Does the new platter work though? Yes it does! Piano music for once sounds like a piano in an über stable way; people talk about pitch stability, but here you have the real thing. Electro-pop music of the 80's that was recorded with quartz PPL locked synthesisers and rhythm generators, suddenly becomes alive as the timing on the Technics really works so well with the added platter mass. Bass is deeper and feels more grown up. The world's best turntables use high mass platters so this was sort of expected.


And particularly this:


The final question is how does the extra mass of the platter affect the dynamics of the direct drive control system. Again we measured. If anything the standard SL-1200 has too much feedback to allow for the DJ scratching use. In fact we do a motor dynamics modification to turn this down a bit. The new platter measures extraordinarily well and for Hi Fi is actually better matched to the "out of the box" dynamics. In fact because of its extra mass it goes some way to improving the stability of the control system when used for Hi Fi. The absolute proof of this is in the listening, and as I said above, five minutes listening to piano music will have you desperately trying to find your credit card!

...which have obviously not been made on a whim, and indeed rather after much considerable thought and deliberation, it's difficult to make a total abandonment of the above statements, and the embracing of an almost entirely opposite approach and methodology, appear as in any way convincing.... ;)

I'll therefore leave it to others to make up their minds as to what's really going on.

Marco.

Mike_New
18-05-2011, 23:16
Hi DSJR,

May I politely suggest to owners of the MN bearing who wish to try this acrylic based platter that the MN bearing introduces some drag not evident in the stock bearing? The MN bearing was designed for heavier platters such as the one that goes with it and may not work so well with a lightweight affair, which will also give totally different loading to the motor electronics I suspect, although it could be argued that when using the stock platter improved things, this won't matter. These things alone alone may be audible..

I do not think you are really in tune with what historically has been happening.....

When I designed my High Precision Bearing I did so with the continuing use of the OEM platter in mind. People then asked me to design a new heavier high quality platter, as a component of the phased upgrade path; which I then proceeded with.

My bearing does not have drag!

Rather it is a high precision honed fit to the outer bearing which is why any mechanically un-informed persons would maybe think of it as drag. The rotation is as smooth as silk, but firm with absolutely no looseness. Which is what is required of a high quality bearing in the context of an audio application. (Think also the bearings in high quality Tape Decks)

The Stock Bearing of the SL1200 has no 'drag' as DSJR refers to it, simply because it is a low cost component built to a price

Unfortunately high precision engineering is labour intensive and involves high precision machine tools and setup times.
For instance the shafts for my bearings are machined on a $200,000 Swiss NC lathe before finish grinding and Gas Nitriding.

The bearing housings (which I machine) are then precision honed to fit the shafts.
It is this overall process that does cost money, and that all other wouldbe vendors of bearings have studiously avoided.
Rather they have all resorted to re-engineering a new shaft and load device into a very weak die cast housing.

Set up times and machine time must be computed into the pricing equations as fixed costs to be amortised over the size of the production run.
That is why I produce my bearings in batch's of 25. I could indeed 'forward- order' 100 shafts but the up-front money would be to high for my liking.

The bearing was never ever designed 'specifically' for heavier platters as DSJR suggests!!

The bearing will work just as well on an acrylic platter as any other
(Assuming that is, that the platter has been machined correctly so as to position the vital components into their correct running location axially)

DSJR suggests that using the stock platter (with my bearing) could improve things!! Does he not know that at this point in time there are over 80 happy users of my bearings around the the world. Not including forward orders from Spain, Portugal, Lithuania, and of course many in the US and Asia.

Mike_New
18-05-2011, 23:23
Hi Marco,

Gee thanks for that posting, it was from the bottom of his heart!!!

WOStantonCS100
19-05-2011, 01:59
Hi DSJR,


I do not think you are really in tune with what historically has been happening!!!!

When I designed my High Precision Bearing I did so with the continuing use of the OEM platter in mind. People then asked me to design a new heavier high quality platter, as a component of the phased upgrade path; which I then proceeded with.

My bearing does not have drag!

Rather it is a high precision honed fit to the outer bearing which is why any mechanically un-informed persons would maybe think of it as drag. The rotation is as smooth as silk, but firm with absolutely no looseness. Which is what is required of a high quality bearing in the context of an audio application. (Think also the bearings in high quality Tape Decks)

The Stock Bearing of the SL1200 has no 'drag' as DSJR refers to it, simply because it is a low cost component built to a price

Unfortunately high precision engineering is labour intensive and involves high precision machine tools and setup times.
For instance the shafts for my bearings are machined on a $200,000 Swiss NC lathe before finish grinding and Gas Nitriding.

The bearing housings (which I machine) are then precision honed to fit the shafts.
It is this overall process that does cost money, and that all other wouldbe vendors of bearings have studiously avoided.
Rather they have all resorted to re-engineering a new shaft and load device into a very weak die cast housing.

Set up times and machine time must be computed into the pricing equations as fixed costs to be amortised over the size of the production run.
That is why I produce my bearings in batch's of 25. I could indeed 'forward- order' 100 shafts but the up-front money would be to high for my liking.

The bearing was never ever designed 'specifically' for heavier platters as DSJR suggests!!

The bearing will work just as well on an acrylic platter as any other
(Assuming that is, that the platter has been machined correctly so as to position the vital components into their correct running location axially)

DSJR suggests that using the stock platter (with my bearing) could improve things!! Does he not know that at this point in time there are over 80 happy users of my bearings around the the world. Not including forward orders from Spain, Portugal, Lithuania, and of course many in the US and Asia.

Thanks for quickly addressing that Mike. When I read that post something really did not seem right about that. I was initially a bit concerned. But, why would something made to such a high tolerance, that bears up exceedingly well under heavy load, not work even better under a lighter load??? From what I understand of the design of your bearing, it was not designed to be dependent upon the weight of the platter. "Making" or even suggesting that the bearing will only work with your platter (and your PSU, and any other product you make or offer)... well let's just leave that kind of drivel thinking and sales pitch to DC.

Mike_New
19-05-2011, 02:32
Hi Biff,
Yes this will always be a problem in any online forum such as this, and in particular one in which the subject matter is Audio. It can lend itself to so much totally uniformed comment.
The problem is that some people just like to posture their opinions and thoughts irregardless of the total lack of any pre study or investigation of the subject matter.

The Grand Wazoo
19-05-2011, 07:00
With the greatest of respect, Mike, if uninformed personal opinions were banned from AoS, it wouldn't be much of a discussion forum.

Marco
19-05-2011, 07:19
Yep, Chris is right.

I know where you're coming from, Mike, but you have to allow people to express their opinion, be it informed or uninformed, and if factually incorrect in some way, then that's the opportunity for those who are informed to correct the errors :)

Just one point designed to help... You may wish to consider not using so many question and exclamation marks (and emboldened text) in your responses, as it makes it look like you're shouting and/or being aggressive, when I know you're not, and instead simply wish to stress a particular point. I'd use them more sparingly, thus maximising their effect better where it really matters. Just a thought, mate :cool:

I'll comment on the other recent posts later after breakfast.

Marco.

Mike_New
19-05-2011, 07:22
Adam,

No, but the problem is:
A lot of people from all over the world (which is good for AoS) do look to this forum for guidance and advice. Discussion is all very well; but let's have informed discussion.
The post that promped this was no where near informed, as I tried nicely to explain.

Marco
19-05-2011, 07:48
Who's Adam? :scratch:

;)

Marco.

Marco
19-05-2011, 08:17
Hi Mike,

When Dave wrote this:


The MN bearing was designed for heavier platters such as the one that goes with it and may not work so well with a lightweight affair, which will also give totally different loading to the motor electronics I suspect, although it could be argued that when using the stock platter improved things, this won't matter.


I think what he was trying to say, in a somewhat confused way, was that the acrylic platter would likely improve on the stock platter under any conditions. I don't think he was saying that the stock platter would better yours in any way.

I may be wrong, but I'm sure Dave will clarify later :)

Also, I think he was hinting at what I wrote earlier:


In fact, in that respect, whilst I'm obviously keen to hear what the acrylic platter sounds like on my own T/T, I'm beginning to wonder just how relevant my findings will be, based on the fact that my T/T has been judiciously modified with a specific sonic goal in mind, and as such contains products complimentary to achieving that goal, which may not harmonise with 'alien' items introduced into the chain, intended to have a different effect.


Yes, no doubt your bearing will work just as well on an acrylic platter as any other, but it could be argued that if the acrylic platter has been designed as part of a system, say to be used in conjunction with existing Timestep products, such as their bearing and PSUs (and no doubt part of Mr Cawley's 'Evo' solution for the SL-1200, as an alternative to the stock platter with Oyaide mat and record weight), then using the platter on an 'alien' T/T, such as mine, may not produce the intended sonic synergy.

Do you see my point (and I think Dave's)?

*However*, that appears not to be the case, as Arthur has already said that he designed the acrylic platter whilst using a STOCK SL-1200, therefore any notion of his platter achieving synergy with existing Timestep products (or the 'Evo') is not necessarily going to be the case...

Since Arthur decided to supply Dave C with the platter, which will effectively be sold as a Sound Hi-fi product, what should've happened, IMO, is that it should've been designed from the ground up with the products Dave C intended to sell it with as a 'complete system', i.e. a Timestep bearing and PSU (and SME 309, or whatever) otherwise all that's happening is an acrylic platter, optimised for use with a stock Techy, is being bolted onto another solution which it may not optimise as effectively.

That's how I see it, and if there's something I'm missing, then perhaps Arthur would clarify?

Marco.

MartinT
19-05-2011, 09:56
My bearing does not have drag!


Indeed not. A simple test of spinning the platter with the power off shows that it is a very well engineered bearing with small frictional losses.

Marco
19-05-2011, 10:07
Indeed, Martin.

Incidentally, you've been rather quiet on a thread which I thought would have been of significant interest to you....

I'd therefore be interested to know what your thoughts are on what's been discussed so far regarding the acrylic platter :)

Marco.

MartinT
19-05-2011, 10:16
I've read this thread with interest (and personal interest since I use Mike's bearing, platter and base plate) but no-one yet seems to have considered the effect of any stray magnetic fields on the type of cartridge used.

Due to the number of windings and size of the coils used, I would expect that there is a spectrum of sensitivity to magnetic flux ranging from moving iron (the worst), moving magnet, moving coil down to types that would be impervious such as strain gauge, piezo and optical.

The only practical observation I can make is that a Grado Prestige Gold (moving iron) is known to be very sensitive to magnetic and electromagnetic fields and indeed sounds horrible in my Technics. Some might say that it sounds horrible anyway. On the other hand, low output moving coils are hardly susceptible at all and that is proven by all my MCs sounding very good in the Technics.

This is not a very scientic observation but someone should be able to measure the effect by connecting the cartridge outputs to an oscilloscope and running them over the spinning platter. In fact, I may try this out myself when I have the time.

Marco
19-05-2011, 10:19
Good point! You see, that's why I wanted your input ;)

Perhaps either Arthur or Mike (or anyone else) would care to comment on that point?

Marco.

MartinT
19-05-2011, 10:21
Incidentally, you've been rather quiet on a thread which I thought would have been of significant interest to you....

Indeed, I had missed this thread until last night.

Contrary to some opinions, I find the look of the acrylic platter quite nice. However, like you Marco, I'm only concerned with sound quality and am keen to discover the fruits of Arthur's design once someone gets their hands on one. Something tells me that, however it sounds, it's going to be different from the stock and MN platters.

It's really going to have to go some to beat an MN platter with Achromat combination since I can't help feeling that we have the best of shielding, rotating inertia and record coupling going on there.

colinB
19-05-2011, 11:06
Before i owned my 1210 , i read many online discussions referring to distortion from the cartridge when tracking the inner grooves of the lp and how the cause was thought to be the transformer underneath the platter.
Is it possible this problem is actually the stray flux and nothing to do with the power supply?

Spectral Morn
19-05-2011, 11:08
I've read this thread with interest (and personal interest since I use Mike's bearing, platter and base plate) but no-one yet seems to have considered the effect of any stray magnetic fields on the type of cartridge used.

Due to the number of windings and size of the coils used, I would expect that there is a spectrum of sensitivity to magnetic flux ranging from moving iron (the worst), moving magnet, moving coil down to types that would be impervious such as strain gauge, piezo and optical.

The only practical observation I can make is that a Grado Prestige Gold (moving iron) is known to be very sensitive to magnetic and electromagnetic fields and indeed sounds horrible in my Technics. Some might say that it sounds horrible anyway. On the other hand, low output moving coils are hardly susceptible at all and that is proven by all my MCs sounding very good in the Technics.

This is not a very scientic observation but someone should be able to measure the effect by connecting the cartridge outputs to an oscilloscope and running them over the spinning platter. In fact, I may try this out myself when I have the time.

Yes indeed Martin

I once had major problems with a Grado on an Avid Diva mk1 TT. This was due to the suggested placement of the motor at the front of the turntable (under the arc of the cart). The motor was not shielded thus created major hum problems. The solution was to use the motor in another position under the deck away from the cart. Thankfully this was possible but the question I asked of Conrad via email at the time was why not shield it from the off ? No satisfactory answer was given bar I suppose it would cost too much. The Diva sold for £1200 at the time.

The new version of this deck is quite different and everything is fixed in position. The idea of the original was you could use two arms and positioning the motor at the front (it had a logo on it) allowed this.

Regards D S D L

Marco
19-05-2011, 15:46
A lot of people from all over the world (which is good for AoS) do look to this forum for guidance and advice.

Ain't that the truth....! ;)

Hi Martin,


It's really going to have to go some to beat an MN platter with Achromat combination since I can't help feeling that we have the best of shielding, rotating inertia and record coupling going on there.


I'm inclined to agree, but I'm also aware that Arthur is not your run-of-the-mill designer. In my experience, he always thinks laterally and looks at the bigger picture, so the acrylic platter he's designed will no doubt contain some valuable sonic qualities.

Marco.

Mike_New
20-05-2011, 00:51
Hi Marco, Martin,

Marco has asked me to give my thoughts on Martins observations concerning the interaction of various types of cartridges in a stray flux.

I believe Martin is correct when he talks about the other affects of stray magnetic fields on various makes and types of cartridges.

However it is now my thought that any stray flux fields could more adversely affect MC cartridges by their interaction with the powerful magnet which these newer quality MCs use. Rather than the interaction with the coils, which was my first observation earlier in this thread.
I have a Benz Ruby MC and the power of the magnet is frightening. (they use rare earth magnets I believe) do not ever go near it with a metal object.

Theoretically, what could happen I believe, is that at a point, the magnet of the MC can be attracted downwards by the stray flux field, which will in turn cause the stylus to move forward along the track as it is compressed against the record.
Now as the flux is alternating at the rate determined by the number of magnetic poles on the rotor magnet, the MC could oscillate in the vertical mode, causing the stylus to move backwards and forwards in the groove.
This will of course have a modulating affect on the reproduce sound.

I have however placed my cartridge over a CD (recording side up) and ran my platter at 45rpm. Even at high volume (effectively 180W per channel) I could not discern any modulation that could be attributed to the stylus moving vertically in sync with the rotation. I did however have trouble getting my arm to stay steady in the one spot.
This is not the ultimate test, I know, as it would be nice to have, say a 1Kz tone recorded at this point from which to replay.
Interestingly it happens that the edge of a CD just about coincides with the point at which any stray flux from the rotor magnet would be greatest.

I did not try this using the OEM platter as I did not want to disturb my setup. I will leave Martin or others to give it a go.

MartinT
20-05-2011, 06:00
Good lateral thinking there, Mike, I hadn't considered the effects on the magnet itself. I will at some point fire up my 'scope and test various cartridges for output when held over the rotating platter to see if there is any real effect.

DSJR
20-05-2011, 06:49
Hi DSJR,


I do not think you are really in tune with what historically has been happening.....

When I designed my High Precision Bearing I did so with the continuing use of the OEM platter in mind. People then asked me to design a new heavier high quality platter, as a component of the phased upgrade path; which I then proceeded with.

My bearing does not have drag!

Rather it is a high precision honed fit to the outer bearing which is why any mechanically un-informed persons would maybe think of it as drag. The rotation is as smooth as silk, but firm with absolutely no looseness. Which is what is required of a high quality bearing in the context of an audio application. (Think also the bearings in high quality Tape Decks)

The Stock Bearing of the SL1200 has no 'drag' as DSJR refers to it, simply because it is a low cost component built to a price

Unfortunately high precision engineering is labour intensive and involves high precision machine tools and setup times.
For instance the shafts for my bearings are machined on a $200,000 Swiss NC lathe before finish grinding and Gas Nitriding.

The bearing housings (which I machine) are then precision honed to fit the shafts.
It is this overall process that does cost money, and that all other wouldbe vendors of bearings have studiously avoided.
Rather they have all resorted to re-engineering a new shaft and load device into a very weak die cast housing.

Set up times and machine time must be computed into the pricing equations as fixed costs to be amortised over the size of the production run.
That is why I produce my bearings in batch's of 25. I could indeed 'forward- order' 100 shafts but the up-front money would be to high for my liking.

The bearing was never ever designed 'specifically' for heavier platters as DSJR suggests!!

The bearing will work just as well on an acrylic platter as any other
(Assuming that is, that the platter has been machined correctly so as to position the vital components into their correct running location axially)

DSJR suggests that using the stock platter (with my bearing) could improve things!! Does he not know that at this point in time there are over 80 happy users of my bearings around the the world. Not including forward orders from Spain, Portugal, Lithuania, and of course many in the US and Asia.

Bloody 'ell Mike, anyone would think I was having a go at you or summat and that my "claim" that your bearing has "drag" is a negative thing. I don't believe I suggested that in the slightest.

This debate is on the verge of getting personal. My techie won't be able to benefit from any of this in any case, so this "uninformed amateur" will bow out at this point :(

DSJR
20-05-2011, 06:54
Indeed not. A simple test of spinning the platter with the power off shows that it is a very well engineered bearing with small frictional losses.

In my ignorant world, friction is one thing, drag is another (try charging a stock bearing with hypoid viscous gear oil and feel the difference. i call this "drag," for want of another term).

Apologies for upsetting experienced engineers..

MartinT
20-05-2011, 07:21
Umm, if there is low friction and the platter spins for a long time, there cannot be drag. The oil that Mike supplies is nothing like as viscous as hypoid.

WOStantonCS100
20-05-2011, 07:25
In my ignorant world, friction is one thing, drag is another (try charging a stock bearing with hypoid viscous gear oil and feel the difference. i call this "drag," for want of another term).

Apologies for upsetting experienced engineers..

My apologies, Dave, if I exacerbated things. It was just that your post wasn't at all specific or clear. Left alone "drag", concerning a bearing, is a pretty negative connotation; so, I can understand Mike's alarm as it did cause me a bit of alarm as well. Even so with your explanation, and mind you neither am I a bearing engineer; I would imagine, if I were, my first quality control check would be to see how the bearing performs under minimal load. If it "dragged" then, there would be no testing with a heavier load. It would immediately be back on the bench for a "re-drawing". I understand what you are saying about "viscosity"; however, it was my understanding that the MN bearing was meant to work with the original platter, as well as, the MN platter, so careful consideration would have to have been given to the matter at the time of design. Mike speaks well for himself, so I'll leave it at that. Again, I didn't mean to rumple feathers if I did.

Mike_New
20-05-2011, 07:27
DSJR,
I can only say in my defence that the term "drag" as defined by Collin's Dictionary
means 'to pull draw or move with some effort'; 'to move or pass with effort"
"to force into action"
I just feel it is not the term one would use to describe it's performance. as Biff observed.

Marco
20-05-2011, 07:33
Anyway, I'd have thought Dave would've known all about "drag", being a 'queen' at the weekends, eh dahhling? :kiss:

:lol:

Marco.

WOStantonCS100
20-05-2011, 07:36
Anyway, I'd have thought Dave would've known all about "drag", being a 'queen' at the weekends, eh dahhling? :kiss:

:lol:

Marco.

Are we talking about bearings or Chaz Bono... or is it Chastity Bono... or is it... :scratch: :eyebrows: I digress, my bad... back on track.

YNWaN
20-05-2011, 09:18
http://www.skf.com/portal/skf/home/products?maincatalogue=1&lang=en&newlink=1_0_38a

Mike_New
20-05-2011, 09:45
Unfortunately not the same thing, it refers to drags losses of a bearing partially or totally submerged in lubricant (oil). What happens is that as the bearing rotates there is indeed a drag as the balls rotate through the oil.
My bearing is a plain bearing which is a bit different.

DSJR
20-05-2011, 09:46
Anyway, I'd have thought Dave would've known all about "drag", being a 'queen' at the weekends, eh dahhling? :kiss:

:lol:

Marco.

Yeah, HiFi Dave and I have a lot to answer for :eyebrows:

YNWaN
20-05-2011, 11:35
Unfortunately not the same thing, it refers to drags losses of a bearing partially or totally submerged in lubricant (oil). What happens is that as the bearing rotates there is indeed a drag as the balls rotate through the oil.
My bearing is a plain bearing which is a bit different.

Indeed, I linked to this item purely because it discusses bearing drag as a concept, independent to friction. However, the shaft of most plain bearings is entirely submerged in lubricant (as discussed in the linked article) and shear forces will exist within the oil film interposed between surfaces (this is true of any lubricated surface and is not intended as a criticism).

Beobloke
23-05-2011, 12:01
Who's Adam? :scratch:

;)

Marco.

Indeed - don't flippin' drag me into this. I sold my Technics last year!

:lol:

chris@panteg
24-05-2011, 11:37
Hi Chris,
I believe in fact Richard has one of my platters.

Hi Mike

Just to clear this up , Richard does not have one of your platters !

He does have a high mass solid platter , not unlike your own ! But one he made himself about 10 years ago , i was a little confused myself :scratch:

CableMaker1
28-05-2011, 17:47
Looks very interesting....

http://www.soundhifi.com/FOURUMIMAGES/platter3.jpg

I liked the sound of the Pink Triangles and Voyd TT that had light weight platters......still miss the Voyd Valdi I had.


Regards D S D L

Dalek - your TT image looks very similar to my TT, except it is in silver, has the stock platter, and the feet are different. Come to think of it, one of my TTs are missing since yesterday. Think I need to interrogate some people now. :cool::cool::cool:

WOStantonCS100
28-05-2011, 18:27
http://www.soundhifi.com/FOURUMIMAGES/platter3.jpg

:scratch: This is going to sound bad coming from someone who has a "polished" but very mechanical looking T3 Pro on his 1200. Although looks are always my last concern when it comes to gear, I have to say, I'm really kinda not liking how that looks on a 1210. If this were the silver face (1200) version, it would just get a straight veto from me regardless of how it sounds and it may indeed sound great. Yes, I know, that's totally wrong; but, this is actually the first case where looks are really a stopping point for me. On a Scheu or Clearaudio (etc.) table, I love the way acrylic (or similar) platters look. I just can't seem to get over this one on a Techy, visually.

CableMaker1
28-05-2011, 18:55
:scratch: This is going to sound bad coming from someone who has a "polished" but very mechanical looking T3 Pro on his 1200. Although looks are always my last concern when it comes to gear, I have to say, I'm really kinda not liking how that looks on a 1210. If this were the silver face (1200) version, it would just get a straight veto from me regardless of how it sounds and it may indeed sound great. Yes, I know, that's totally wrong; but, this is actually the first case where looks are really a stopping point for me. On a Scheu or Clearaudio (etc.) table, I love the way acrylic (or similar) platters look. I just can't seem to get over this one on a Techy, visually.

I admit I like how the acrylic looks on the TT. I do agree with you that ashetics are important. However, I have to admit, I love the look of the stock platter with the strobe dots on it.

Mike News platter looks good from a 180 degree angle. And yes, I am one of Mike New's 80 happy customers having his bearing in my TT.

I know Mike New uses a copper-top on his platter. Is it recommended to use a mat when using his platter? If one had a copper mat and then purchased his platter, would anyone know if their is a sonic benifit to use or not to use a copper mat on top of his platter?

DSJR
28-05-2011, 20:42
I like the looks too, although I've seen the use of a Herbies mat betwixt platter and record, which sort-of defeats the point of the acrylic (better termination of the vinyl. I'm sure I'd like it though, but not for £500 - you could have a decent turntable for that amount :rolleyes:

Mike_New
29-05-2011, 00:06
hi Mike,

=I know Mike New uses a copper-top on his platter. Is it recommended to use a mat when using his platter? If one had a copper mat and then purchased his platter, would anyone know if their is a sonic benifit to use or not to use a copper mat on top of his platter?

I orignally produced the Copper Bonded Platter for Marco as a special request, and then realised it was possibly a nicer looking platter so I have kept with this design.
Also the bonded 3mm Annealed Copper provides superior sonics on certain types of replay. according to feedback from some of the many users who now have them.

A lot of people have mentioned the gap around the periphery of the platter on Martin's SL1200. I am now getting better quality Alluminium blanks from my suppliers, which permits a larger overall outside diameter to be obtained.

In regard to the use of a mat.
Yves in canada I believe has been using a TTWeights copper mat with my platter and recons it's fantastic.

I have been using the 3mm Achromat with the machined allowance for the label and have, like many others found it to be possibly the best combination with my platter. Providing you make sure that it is properly 'connected' to the surface of the platter with a good quality silicon grease or the popular alternative!

I am currently using what I believe is a mat from a Mk5; which to my surprise, when doing some level tests, I discovered is actually moulded with a concave surface of about 1.4mm from edge to label area. When mounted onto the platter and measured with the edge of a good quality engineers steel ruler.
This mat is perfect for use with the warped records that I have (using a centre weight of course) The mat is the usual type with the sets of circular ribs on it's surface. When placing the weight onto the record you can see the record being pulled into contact all over. And unlike the metal versions the material is soft and pliant allowing the record to find it's own optimum contact seating all over.
It maybe that what I have is a specially produced mat by some supplier that has long since moved on.

I have no idea how many of these may have been produced, but certainly the mat on my older test-bed SL1200Mk2 does not have this feature.
I must admit that I now use this most of the time as it seems to give me excellent sonics with my platter on all records.
What would be nice to try, is the Achromat with the same treatment. maybe this could be achieved sometime.

Another mat which gives good results with my platter, is the soft thin mat produced by Origin Live. However this does not have a label recess which is a shame. It's the mat which smells like corn chips.

Laying your record onto the flat surface of my platter is a sure way to check for warping, I was rather surprised to find how many warped ones I had.

MartinT
29-05-2011, 04:45
A lot of people have mentioned the gap around the periphery of the platter on Martin's SL1200. I am now getting better quality Alluminium blanks from my suppliers, which permits a larger overall outside diameter to be obtained.

It was the base plate that elevated it like that. In any case, photography tends to exaggerate it - in real life, it's just not a problem for me.

I'd also like to recommend both the Achromat and Michell clamp as the best combination of coupling I've yet tried, the Achromat bonded to the platter with a thin film of Vaseline. In fact, it's so good like this that I'm unlikely to experiment any further.

etphonehome
29-05-2011, 08:45
I am using the Origin Live mat with the MN platter. I like it better than the stock rubber Techie mat. Origin Live mat is much more open sounding with better air and separations.

Waiting for my Achromat to come in. Will do a comparison then.

DSJR
29-05-2011, 09:31
I remember the ex-technics engineer who posted here (before being all but hounded away) mentioned the slightly concave record mounting - and why...

MartinT
29-05-2011, 09:39
I remember the ex-technics engineer who posted here (before being all but hounded away) mentioned the slightly concave record mounting - and why...

On the standard platter? That would have little effect without a weight in the middle.

The Michell clamp simply works the other way, creating a slight convex surface. Both are good for reducing the effects of warps.

DSJR
29-05-2011, 09:51
Sorry, the MAT, not the platter :)

MartinT
29-05-2011, 10:18
Ah, ok. Was the idea that the record sagged a bit under its own weight, to fit the concave surface?

Marco
29-05-2011, 10:19
I remember the ex-technics engineer who posted here (before being all but hounded away)...

I don't think that's quite the case, Dave. No-one gets "hounded away" from here unless we sense they have an agenda. And the only time the chap you're referring to contributed to discussions was to pooh-pooh (perfectly well thought-out and designed) aftermarket modifications for the SL-1200.

It's almost as if he took it all personally... And when I challenged him on that, he went into a huff and left. There was definitely something strange about his presence here. Anyway, we move onwards and upwards! :)

Marco.

chris@panteg
29-05-2011, 10:33
Sorry, the MAT, not the platter :)

Hi Dave

If the information i have is correct , the OEM rubber mat is designed to sit on the lip and you are supposed to use a weight with it (not a clamp) for best results !

Interesting that Dave Cawley has been saying for some time its a design fault ? I don't think so , I've not used the rubber mat for over 2 years now , so now i have this alchemist weight , its time for a revisit i think , probably hate it but WTF.

DSJR
29-05-2011, 13:05
The "lip" is a tiny fraction of a mm on the SL1500, so the mat would barely register it I think. The mat moulding does seem to have a small dip towards the centre though.

etphonehome
31-05-2011, 16:31
Received the Achromat today. Compared it to the Origin Live mat. Prefer the latter; the Achromat sounded congested in comparison. Prefer the the more open sounding OL mat.

colinB
31-05-2011, 16:42
Received the Achromat today. Compared it to the Origin Live mat. Prefer the latter; the Achromat sounded congested in comparison. Prefer the the more open sounding OL mat.

If you are using the standard platter can you use the OL mat direct or do they recommend using with a rubber mat underneath?

etphonehome
31-05-2011, 16:47
If you are using the standard platter can you use the OL mat direct or do they recommend using with a rubber mat underneath?

I am using it on the MN platter now.

I used the OL mat directly on the stock platter before; it did not work for me. I actually had good results using the OL mat on top of the Oyaide mat. Did not try it on the rubber mat though.

MCRU
31-05-2011, 16:50
Hi guys
Been busy, are we on about TT mats again? You simply must try the blue horizon mat chaps, highly recommended.

etphonehome
31-05-2011, 16:55
Hi guys
Been busy, are we on about TT mats again? You simply must try the blue horizon mat chaps, highly recommended.
:eyebrows: Hoping to win that in THE Competition.