View Full Version : My Second “Techie” – well all of it!
This is my second Technics deck. The purpose of this project is to build a deck for my Girlfriend. She has no knowledge of turntable set up etc and just wants a reliable manual deck she won't have to fuss with. My aim is to apply simple, low cost modifications to produce a good quality reliable deck for her. This is the donor deck purchased off fleabay for £150.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_001.jpg
The first step was to fill the unwanted holes where the DJ features used to be. Nothing fancy, just filled them with Plastic Padding’s "Chemical Metal" I didn't even strip the paint off the deck, just roughened the surface with some coarse sand paper. The hardest part was filling the small edge chamfers to create a square edge for the veneer.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_002.jpg
Started to apply the veneer, it was left over from my first Technics project and is American Black Walnut. Because I was using left over pieces, the top had to be made from three separate bits of veneer.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_003.jpg
The veneer went on well. Can you spot the joins? :D
I gave the motor well and arm location a coat of Black acid etch primer just to freshen it up.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_004.jpg
The first coat of Danish Oil applied (Natural no stain). When this dries the grain will be filled, prior to applying a couple of finishing coats of the Danish oil.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_005.jpg
Moving on to the Tone arm, I decided to modify the existing arm rather than buy an alternative. The Technics headshell has an offset angle of 22 degrees but this is only correct for their own alignment geometry. If you calculate for Baerwald alignment it requires an offset of 23.7 degrees so you have to twist the cartridge in the mounting slots.
The Linn LV-X headshell is at an angle of 24 degrees, the 0.3 degree difference over my preferred Baerwald figure of 23.7 is so small as not to be noticeable by eye, plus the cartridge mounting slots will easily allow for this. I will of course be setting the cartridge to the correct angle using a suitable Baerwald protractor.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_002.jpg
The picture on the left shows the (Rare) brand new headshell I picked up off eBay. Got it for a price, below what I've seen second hand ones go for, so well pleased. The picture on the right shows the headshell after I have stripped out the multi pin connector and cartridge leads. One of the things I like about this headshell is that the connecting stub is not a separate piece, but part of the die casting. This removes a mechanical fixing interface, which I am all in favour of. Another key attribute is that the stub is 8mm diameter, I plan on making a straight arm from roll wrapped carbon fibre tube, OD 10mm x ID 8mm, so the stub should fit with a bit of persuasion. Also the stock bearing yoke which accepts the arm tube has a 9.5mm hole, so I should be able to work a way of fixing the tube in there as well, enlarging the hole with a 10mm drill or sanding the outside of the tube, or a bit of both.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_003.jpg
One of the first things I've done is to fill the balance weight stub with Black Silicone sealant. I had to alter the metal threaded bracket that normally covers the opening to allow this. It’s basically a threaded insert, a right angle piece of metal, with a threaded hole in each limb. One hole to take the fixing screw that retains the copper tag on the underside of the stub and the other on the end of the stub to take an additional threaded weight. I simply cut off the portion of the bracket that blocked the opening of the stub and left the rest to do its job of retaining the copper tag which holds the large main weight in place.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_004.jpg
The roll wrapped carbon fibre tube is much more rigid than a pulltruded tube. It is 10mm O.D. x 8mm I.D. I glued an 8mm O.D. x 6mm I.D. Aluminium tube inside the Carbon tube, it was a very tight fit and I needed a hammer to drive the last 30mm home.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_005.jpg
The components were dry fitted so I could work out the length of tube required. I did this by fitting a cartridge in the centre of the adjustment slots on the headshell and tried lining the stylus up with the arc on an alignment protractor. I just kept sanding a bit at a time off the tube on a belt sander, till the length was right to make the alignment. I then glued the tube into the bearing yolk. Once this had dried I levelled the table and placed a block of wood under the arm. I adjusted the VTA till the arm was perfectly level then glued the headshell in place making sure it was level in all directions and therefore parallel to the platter.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_006.jpg
Completed Arm. It certainly looks the part, all it needs is a single length of Cardas wire from headshell to Phono stage and its ready to try out. The mass of the arm/headshell worked out well at 22g. The Technics arm/headshell weighs 24g, so not much difference. The combination of Carbon/Aluminium tube is much better than carbon on its own which would have come in at 13g including headshell. Where the difference lies is in the distribution of the mass. The Technics is 24g but 16g is hung off the end in the form of headshell and connector. The tube itself weighs only 8g. With this modification the mass is more evenly distributed along the length, 5g for the headshell, 17g for the tube.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_007.jpg
This is the Cardas cable I used to wire the Tone Arm.
It's 33awg litz copper made up as twisted pairs then wrapped in PTFE, this bundle (1.5mm dia) is then covered with a tinned copper braid and finally a soft flexible jacket making an overall diameter of 3mm.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_008.jpg
The jacket, coax shield and PTFE wrap were stripped off the length of cable running inside the arm, it wouldn't be flexible enough otherwise. An additional strand of wire was run through the arm for grounding, it's connected to the screw on the right which is threaded into the conductive carbon wand and the stub of the headshell. The other screw is threaded into the carbon and the inner Aluminium tube, so all the elements are grounded, this was confirmed when checked for continuity.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_009.jpg
The additional ground wire plus a length of equipment wire were soldered to the coax braid inside the base of the Tone Arm. The joint was tidied up with some heat shrink sleeving and the cables tied down using "P" clips at the screw bosses originally used to hold down the small PCB. The base cover plate and cable retaining block would be fitted as normal, the thick cable containing the cartridge leads was left long enough to reach the Phono stage and the single piece of equipment wire runs to the TT grounding point at the corner fixing of the main PCB.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_010.jpg
The ends of the phono lead were fitted with chuck type plugs. I separated the individual twisted pairs and applied red and black heat shrink. The diameter of the leads required increasing to work with the crimp retaining feature on the plug, I did this by applying several layers of heat shrink. The braided screen was terminated with a piece of equipment wire and a loop solder tag, again heat shrink applied at the three way junction to tidy it up and strengthen the joint.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_007.jpg
The Deck was treated to one of my modified bearings which has the bush and thrust pad running in oil. This mk II version has a thrust pad made from PEEK and the end cap is solid brass with a pocket made using an end mill cutter in a pillar drill. Instead of a paper sealing gasket for the cap I used spray on gasket.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_008.jpg
The Deck also received an external PSU and upgraded Regulator as per 6L6’s design.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_009.jpg
I removed the stock feet and replaced them with 50mm diameter Sorbothane semi-spheres.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_010.jpg
The platter was fitted and she's ready to try out.
I really like the simplicity of this decks appearance.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_011.jpg
She fired up without any problems.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_012.jpg
I think the finished article looks really smart, all I need now is a dust cover. I don't use one myself, but like I said, this deck is for my girlfriend and she wants one fitting. :rolleyes:
I hope this will give some inspiration to other budding modifiers, it has an upgraded Bearing, PSU, Regulator and Arm and including the purchase price of the deck and the arm re-wire has cost less than £320 in total to reach this build level. :)
Utterly gorgeous. Well done, that's a great rebuild.
Hal55
:drool:
Fantastic work Ken - one of the nicest looking turntables I've ever seen.
Fantastic Ken!
Thanks for sharing.
The deck looks brilliant btw.
Tony
PS, you should go into business making these decks.
RobbieGong
30-12-2013, 23:01
Very nice work :thumbsup:
Audio Al
31-12-2013, 01:55
Very smart and sleek looking
We'll done
Gordon Steadman
31-12-2013, 08:24
Beautifully done. Simple works for me - but then it has always had to!!
prestonchipfryer
31-12-2013, 08:30
Fantastic. Looks wonderful.
Nice work Ken Agree with Tony you should consider doing this as a business
Thats fantastic, showing some great skills there!
Just curious about speed stability: now you've removed the pitch controls, does the 1210 remain stable all the time at 33.33/45 RPM?
Beautiful job, really love that veneer
How's she sound with that arm?
Speed controls - this is a common mistake.
The techie is quartz locked and checks/adjusts its speed many times a second.
The pitch fader is designed to force the electronics to deviate from the correct speed, not adjust it.
The fader has to be calibrated to match the correct speed when set to the centre position (zero). Many speed problems can be linked to this being out of calibration, that is, when set to zero it is actually increasing or decreasing the speed from what it should be. If you have to set this to anything but zero to get the strobe dots to be correct, check this circuit, it has a resistance trimmer for adjustment. There is a YouTube clip (viperfrank) on how to check this and what the correct resistance should be - memory not what it was (you need a meter).
If you remove the fader circuit compleatly it removes any bias and runs true, and yes this does mean that the strobe dots are actually not needed and are just for show, or to indicate when the fader is out of calibration. If anyone has doubts about speed and think it may be the fader, unclip the fader harness from the PCB and bridge (connect) the two centre pins on the board socket, No's 6 & 7. If the speed is now true it is the fader at fault, if it continues to be out, the fault lies elsewhere. ;)
I need to set the cartridge up, but I might get to it later today as I am keen to hear what the arm sounds like myself. The Ortofon 2M Red which is fitted was on the arm prior to modifications.
Will report back.
Thanks for clearing that up Ken, http://theartofsound.net/forum/images/icons/icon14.png
Well I've run into a bit of a problem.
No music coming from the right channel :steam:
Did a bit of lead swapping and rulled out the phono stage and everything downstream of it.
Checked continuity from cartridge tags to plugs on end of lead, all fine and no cross talk between them :scratch:
Suspecting may have lost right channel on cartridge.
Checked between all the plugs at the phono stage end of the lead and the TT ground - Ah there is a short between the right channel signal lead (Red) and the TT ground.
Thought at first I might have burnt through the insulation when soldering the thicker ground wire to the braided shield, even though the signal leads are PTFE wrapped. I cut the plugs off the lead and tried upstream but still shorting. It may be at the junction inside the tonearm base where I soldered to the braid in a similar way, but it is more likely that the very fine unprotected lead has caught a sharp edge somewhere and is touching bare metal in the arm or base.
Either way it means the whole thing has to come appart again :doh:
Lesson learnt - Don't just check for shorting between the cartridge leads. Before you build everything up check for shorting on the chassis.
First time I have ever had this problem, just means a bit of time and effort before I can play some music. The one channel that did work sounded good but you need to here both to make a proper call.
Located the problem.
When I bolted the arm into its base, the Red lead had formed a loop and got trapped between the two.
Tightening it down had breached the insulation and it was shorting against the bare casting which is grounded.
Now I know what happened I can do something about it.
Will report back on how the arm sounds when I get it sorted.
:stalks:
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Wow! I'm past words - that's utterly fantastic!
(And I can't believe how good your veneering looks. Astonishing!)
Thanks for all the great comments guys.
There are reasons why I don't do this as a business.
First, I don't have a workshop or proper equipment, I do all this in my kitchen, or outside, weather permitting, so not a lot lately.
Second, it is a labour of love and the £320 it cost me does not include any of my time or if I had a workshop/equipment the overheads.
Even working on the minimum wage level you would have to add £1000+ to the price. At that level it is not so atractive as a purchase.
This is why the DIY route is so rewarding, if you forget about the time you have spent and the dust all round the house, you can build somthing which would cost many times more in the shops and have it exactly as you want it.
The veneering really isn't that hard to do, I used the Iron on variety, if you lack confidence try doing something other than your deck to develop the knack. I had only tackled two sets of speakers prior to the two Turntables. I learnt many of the techniques I use off YouTube (The Web is your friend). Hadn't heard of Danish, or Tung Oil till I did the decks. You don't know what you can do till you try, I take the attitude that I will not be defeated, if something doesn't work, I try doing it different.
Steps down off soap box :D
Setting Son
01-01-2014, 20:19
Excellent work, Ken. Looks amazing; I'm sure your gf will be delighted with it.
Gordon Steadman
01-01-2014, 20:45
The veneering really isn't that hard to do, I used the Iron on variety
I'm not sure I'd agree with that. Even with iron on its more than easy to mess it up. I always use contact adhesive as I tend to trust the bond a bit more than with the iron on stuff. Veneering well takes care and a certain amount of skill. The results you have show no lack of skill at all.:)
Ken, I've only just seen this thread - outstanding :) - looks really good!
I've used iron on veneer in the past and would agree that it is pretty easy to use - you've still done a really excellent job of it though.
So, how about spray the platter and buttons black - pick out the lettering on the buttons in silver? laser etch the Technics logo into the veneer - that works very nicely ;).
Gordon - How do you apply the contact adhesive?
I have allways had problems getting an even film, admittedly not on veneering projects.
The thing about contact adhesive is it never sets hard and you always get that flexibility or give in the surface, depending on how thick you apply it of course, then there is the major draw back that you only get one chance to position it.
Don't you find the glue tears away at the edges in streaks when you sand it, forms bobbles of rubbery glue? The Iron on does this as well but to a lesser degree. I am considering using the PVA Iron on technique in future, as apposed to the pre coated hot melt I have been using, as I think even better results may be achievable with that.
Mark - There is lots I could have tried, I even considered some marquetry (no pun intended) but I settled for this look as it sits well with her (GF) old silver Technics amp and Tannoy M20 speakers which are Walnut.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_013.jpg
I got the arm wiring sorted. :carrot:
So what does the arm and other mods sound like?
It just has more authority, delivering a richer fuller sound from a densely black background. Sound stage is much more evident and a lot wider. The bass is deeper and nicely textured; the overall sound makes the stock arm sound thin and veiled in comparison.
I’m very pleased with the end result both visually and sonically.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_013.jpg
I got the arm wiring sorted. :carrot:
So what does the arm and other mods sound like?
It just has more authority, delivering a richer fuller sound from a densely black background. Sound stage is much more evident and a lot wider. The bass is deeper and nicely textured; the overall sound makes the stock arm sound thin and veiled in comparison.
I’m very pleased with the end result both visually and sonically.
A triumph Ken, can you please stop posting pictures now as it is making folk very envious.:lol: Looks stunning!:champagne:
:D ok Andy, I will concentrate on my deck now and how to incorporate the Techie motor, 3 1/2 Kilo Acrylic platter and linear tracking arm into a new plinth :eyebrows:
A triumph Ken, can you please stop posting pictures now as it is making folk very envious. Looks stunning!
I agree! It's fantastic and makes me want to go buy another just to do those mods!
In actual fact Ken, we need more pictures.:eek:
Gordon Steadman
04-01-2014, 08:51
Gordon - How do you apply the contact adhesive?
I have allways had problems getting an even film, admittedly not on veneering projects.
The thing about contact adhesive is it never sets hard and you always get that flexibility or give in the surface, depending on how thick you apply it of course, then there is the major draw back that you only get one chance to position it.
Don't you find the glue tears away at the edges in streaks when you sand it, forms bobbles of rubbery glue? The Iron on does this as well but to a lesser degree. I am considering using the PVA Iron on technique in future, as apposed to the pre coated hot melt I have been using, as I think even better results may be achievable with that.
Hi Ken,
The secret is to put the glue on as thin as possible, the serrated widgets supplied are useless and you end up with thick patches. OK for kitchen worktops but not for finer work. I use a scraper. Admitedly, you only get one shot at it but it means getting it right first time:eyebrows:
The joints are the dodgy bit of course. Corners are easy enough, the usual problem is not letting the glue go hard before cutting and sanding, yes the glue grabs but it takes time to go hard. Flat joints are overlayed and cut with a scalpel. I find that, if the glue was thin enough, there is no problem in scraping it a little an then applying more up to the join line. I think one of the problems is that, as the glue is 'instant', the assumption is that it will be quick. As with all things, to do the job properly, requires the right amount of time applied too.
However, considering the results you have achieved, I see no reason for not just carrying on the way you do it now.
Thanks for the input on your gluing technique.
The reason I am considering changing is that the hot melt that the suppliers coat the veneer with is a light creamy colour.
This is ok on light coloured veneer, but on darker colours like the Walnut you can sometimes get a light colourd joint line at the edges.
This is a pain to try and eliminate or disguise. PVA dries clear and harder so I suspect it will be easier to sand and invisible, I havn't tried it yet so I am guesing. There is a YouTube tutorial from the woodworkers guild of America, or somthing similar sounding, that shows this technique and is what brought it to my attention. You coat both surfaces with PVA and let it dry. Position the veneer and press down with an iron. The heat melts the PVA like a hot melt so its like making your own iron on veneer. Sounds good in theory.
Like you said I am getting pretty good results now, just looking for the easiest opption for the future.
Gordon Steadman
04-01-2014, 11:12
Thanks for the input on your gluing technique.
The reason I am considering changing is that the hot melt that the suppliers coat the veneer with is a light creamy colour.
This is ok on light coloured veneer, but on darker colours like the Walnut you can sometimes get a light colourd joint line at the edges.
This is a pain to try and eliminate or disguise. PVA dries clear and harder so I suspect it will be easier to sand and invisible, I havn't tried it yet so I am guesing. There is a YouTube tutorial from the woodworkers guild of America, or somthing similar sounding, that shows this technique and is what brought it to my attention. You coat both surfaces with PVA and let it dry. Position the veneer and press down with an iron. The heat melts the PVA like a hot melt so its like making your own iron on veneer. Sounds good in theory.
Like you said I am getting pretty good results now, just looking for the easiest opption for the future.
Yup,
The theory sounds fine. I would be a bit nervous with very thin veneers though as they tend to wrinkle as soon as they get the slightest bit damp. The contact pulls them down flat. I'm not sure how the PVA will react. Only one way to find out!!
Tiff_Needle
06-01-2014, 02:46
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_013.jpg
I got the arm wiring sorted. :carrot:
So what does the arm and other mods sound like?
It just has more authority, delivering a richer fuller sound from a densely black background. Sound stage is much more evident and a lot wider. The bass is deeper and nicely textured; the overall sound makes the stock arm sound thin and veiled in comparison.
I’m very pleased with the end result both visually and sonically.
In a word... "STUNNING"
keiron99
15-01-2014, 20:59
This looks absolutely superb.
Can I please ask, can someone point me to simple instructions on how to bypass / remove the stylus light and the strobe, including removal of the on/off? (Mine has an external Paul Hynes power supply but the power switch is still in the circuit.)
Hi Keiron
The cue light harness can simply be unplugged from the main PCB to take it out of cicuit.
This can be done from the top by removing the platter and plastic cover if one is fitted.
To remove the cue light from the deck you will have to remove the back cover, check out viperfranks YouTube tutorials.
The strobe light can be disabbled in a similar way, but to get the maximum benefit by reducing the background noise you need to remove the switching transistor Q202 from the board. As I understand it, this transistor switches 50 times a second shunting the strobe LED's to ground and causing them to flicker at that frequency. Even with the strobe removed the transistor still switches so is best removed and is what I do.
The On/Off switch is another matter. I am not familiar with how it is wired into your PH power supply circuit so can not advise for certain (safely).
keiron99
16-01-2014, 09:09
[QUOTE=Qwin;513528]
The first step was to fill the unwanted holes where the DJ features used to be. Nothing fancy, just filled them with Plastic Padding’s "Chemical Metal" I didn't even strip the paint off the deck, just roughened the surface with some coarse sand paper. The hardest part was filling the small edge chamfers to create a square edge for the veneer.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_002.jpg
What did you use as a "backing" on the holes (such as the pitch slider) to hold the Chemical metal in place?Thanks.
keiron99
16-01-2014, 09:44
Masking tape.
Thanks. And then the Chemical Metal just stays in place? Just that it seems unlikely! (I'm intending to paint mine, whereas your veneer perhaps helps structurally?)
If you check this service/repair tutorial for the power switch it will tell you eveything you need to know to access it.
http://www.youtube.com/watch?v=7JHfWYymgEs
Check out the other tutorials that viperfrank has done as they will probably answer all your questions in pictures.
He is very knowledgable and has done many many clips covering everything from tone arm removal, VTA adjuster servicing, to pitch fader calibration. search for viperfrank on youtube, I just did and he covers virtually every job you could imagine on a Technics.
The chemical metal is basically glue. It is polyester resin with a filler. It is very hard when set and resists quite high temperatures and is oil resistant. The masking tape is purely to stop it running through the hole in the bottom (apply filler from the top) when you spread/pour it in. You remove the tape when set. You have to sand the top surface flush with the deck so slightly over fill. It behaves pretty much like car body filler, in fact as you are painting the deck I would roughly fill with chemical metal and then final say 1/2mm with body filler. The CM is hard and difficult to sand I used it because it would handle the high temperature of the iron used to apply the veneer. You do not require this heat resistance and body filler will sand easier and produce a good finish with far less work.
keiron99
16-01-2014, 13:39
Thanks.
I couldn't find any instructional videos on how to completely bypass the power switch.
Paul Hynes have in fact sent me wiring diagrams - many thanks to them for that - but it is way beyond my capabilities.
I guess I will simply have to resort to sticking some insulation tape over that hideous red strobe light!
Keiron - You can disconnect the red light by unplugging the harness on the main board, the switch function would still work.
How you bypass the switch very much depends on what its function is in the circuit.
Is it switching AC mains going to your power supply or the DC comming from your power supply?
Does your PH power supply have an on/off switch on its case? I am presuming it is an external device.
If you send me a copy of the wiring diagram I will see if I can advise you, send an email to jkwynn@jkwynn.co.uk
A close up photograph of the back of the switch area would also be useful if you have got as far as taking it appart.
Could you give me an idea of your skill level? Can you solder for instance, have you built any electronic kits or speaker x-overs?
Just trying to establish if this is something you should be tackling yourself or maybe farming out to a suitably proficient tradesman.
It's ok to customise your plinth with little danger, changing the electrics can be dangerous and also detrimental to your deck if done incorrectly. ;)
keiron99
16-01-2014, 16:02
Many thanks, Ken. I've sent you an email.
Floyddroid
27-01-2014, 22:52
Bloody hell. Just fell in love with that there TT. If you ever want to sell it please let me know.
This is my second Technics deck. The purpose of this project is to build a deck for my Girlfriend. She has no knowledge of turntable set up etc and just wants a reliable manual deck she won't have to fuss with. My aim is to apply simple, low cost modifications to produce a good quality reliable deck for her. This is the donor deck purchased off fleabay for £150.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_001.jpg
The first step was to fill the unwanted holes where the DJ features used to be. Nothing fancy, just filled them with Plastic Padding’s "Chemical Metal" I didn't even strip the paint off the deck, just roughened the surface with some coarse sand paper. The hardest part was filling the small edge chamfers to create a square edge for the veneer.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_002.jpg
Started to apply the veneer, it was left over from my first Technics project and is American Black Walnut. Because I was using left over pieces, the top had to be made from three separate bits of veneer.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_003.jpg
The veneer went on well. Can you spot the joins? :D
I gave the motor well and arm location a coat of Black acid etch primer just to freshen it up.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_004.jpg
The first coat of Danish Oil applied (Natural no stain). When this dries the grain will be filled, prior to applying a couple of finishing coats of the Danish oil.
http://www.jkwynn.co.uk/Project_Images/Tech2/T2_005.jpg
Moving on to the Tone arm, I decided to modify the existing arm rather than buy an alternative. The Technics headshell has an offset angle of 22 degrees but this is only correct for their own alignment geometry. If you calculate for Baerwald alignment it requires an offset of 23.7 degrees so you have to twist the cartridge in the mounting slots.
The Linn LV-X headshell is at an angle of 24 degrees, the 0.3 degree difference over my preferred Baerwald figure of 23.7 is so small as not to be noticeable by eye, plus the cartridge mounting slots will easily allow for this. I will of course be setting the cartridge to the correct angle using a suitable Baerwald protractor.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_002.jpg
The picture on the left shows the (Rare) brand new headshell I picked up off eBay. Got it for a price, below what I've seen second hand ones go for, so well pleased. The picture on the right shows the headshell after I have stripped out the multi pin connector and cartridge leads. One of the things I like about this headshell is that the connecting stub is not a separate piece, but part of the die casting. This removes a mechanical fixing interface, which I am all in favour of. Another key attribute is that the stub is 8mm diameter, I plan on making a straight arm from roll wrapped carbon fibre tube, OD 10mm x ID 8mm, so the stub should fit with a bit of persuasion. Also the stock bearing yoke which accepts the arm tube has a 9.5mm hole, so I should be able to work a way of fixing the tube in there as well, enlarging the hole with a 10mm drill or sanding the outside of the tube, or a bit of both.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_003.jpg
One of the first things I've done is to fill the balance weight stub with Black Silicone sealant. I had to alter the metal threaded bracket that normally covers the opening to allow this. It’s basically a threaded insert, a right angle piece of metal, with a threaded hole in each limb. One hole to take the fixing screw that retains the copper tag on the underside of the stub and the other on the end of the stub to take an additional threaded weight. I simply cut off the portion of the bracket that blocked the opening of the stub and left the rest to do its job of retaining the copper tag which holds the large main weight in place.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_004.jpg
The roll wrapped carbon fibre tube is much more rigid than a pulltruded tube. It is 10mm O.D. x 8mm I.D. I glued an 8mm O.D. x 6mm I.D. Aluminium tube inside the Carbon tube, it was a very tight fit and I needed a hammer to drive the last 30mm home.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_005.jpg
The components were dry fitted so I could work out the length of tube required. I did this by fitting a cartridge in the centre of the adjustment slots on the headshell and tried lining the stylus up with the arc on an alignment protractor. I just kept sanding a bit at a time off the tube on a belt sander, till the length was right to make the alignment. I then glued the tube into the bearing yolk. Once this had dried I levelled the table and placed a block of wood under the arm. I adjusted the VTA till the arm was perfectly level then glued the headshell in place making sure it was level in all directions and therefore parallel to the platter.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_006.jpg
Completed Arm. It certainly looks the part, all it needs is a single length of Cardas wire from headshell to Phono stage and its ready to try out. The mass of the arm/headshell worked out well at 22g. The Technics arm/headshell weighs 24g, so not much difference. The combination of Carbon/Aluminium tube is much better than carbon on its own which would have come in at 13g including headshell. Where the difference lies is in the distribution of the mass. The Technics is 24g but 16g is hung off the end in the form of headshell and connector. The tube itself weighs only 8g. With this modification the mass is more evenly distributed along the length, 5g for the headshell, 17g for the tube.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_007.jpg
This is the Cardas cable I used to wire the Tone Arm.
It's 33awg litz copper made up as twisted pairs then wrapped in PTFE, this bundle (1.5mm dia) is then covered with a tinned copper braid and finally a soft flexible jacket making an overall diameter of 3mm.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_008.jpg
The jacket, coax shield and PTFE wrap were stripped off the length of cable running inside the arm, it wouldn't be flexible enough otherwise. An additional strand of wire was run through the arm for grounding, it's connected to the screw on the right which is threaded into the conductive carbon wand and the stub of the headshell. The other screw is threaded into the carbon and the inner Aluminium tube, so all the elements are grounded, this was confirmed when checked for continuity.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_009.jpg
The additional ground wire plus a length of equipment wire were soldered to the coax braid inside the base of the Tone Arm. The joint was tidied up with some heat shrink sleeving and the cables tied down using "P" clips at the screw bosses originally used to hold down the small PCB. The base cover plate and cable retaining block would be fitted as normal, the thick cable containing the cartridge leads was left long enough to reach the Phono stage and the single piece of equipment wire runs to the TT grounding point at the corner fixing of the main PCB.
http://www.jkwynn.co.uk//Project_Images/TechArm/TechArm_010.jpg
The ends of the phono lead were fitted with chuck type plugs. I separated the individual twisted pairs and applied red and black heat shrink. The diameter of the leads required increasing to work with the crimp retaining feature on the plug, I did this by applying several layers of heat shrink. The braided screen was terminated with a piece of equipment wire and a loop solder tag, again heat shrink applied at the three way junction to tidy it up and strengthen the joint.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_007.jpg
The Deck was treated to one of my modified bearings which has the bush and thrust pad running in oil. This mk II version has a thrust pad made from PEEK and the end cap is solid brass with a pocket made using an end mill cutter in a pillar drill. Instead of a paper sealing gasket for the cap I used spray on gasket.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_008.jpg
The Deck also received an external PSU and upgraded Regulator as per 6L6’s design.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_009.jpg
I removed the stock feet and replaced them with 50mm diameter Sorbothane semi-spheres.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_010.jpg
The platter was fitted and she's ready to try out.
I really like the simplicity of this decks appearance.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_011.jpg
She fired up without any problems.
http://www.jkwynn.co.uk///Project_Images/Tech2/T2_012.jpg
I think the finished article looks really smart, all I need now is a dust cover. I don't use one myself, but like I said, this deck is for my girlfriend and she wants one fitting. :rolleyes:
I hope this will give some inspiration to other budding modifiers, it has an upgraded Bearing, PSU, Regulator and Arm and including the purchase price of the deck and the arm re-wire has cost less than £320 in total to reach this build level. :)
337alant
27-01-2014, 23:25
Excellent job Ken;), I like the wood actually it makes a nice change from the norm :eyebrows:
Alan
Steve - Alan - Thanks for the comments.
I am currently working on a 3rd techie with a 38mm thick acrylic platter scavenged off a Project rpm9.
Hope to have it ready for the next NEBO.:eyebrows:
I am currently working on a 3rd techie with a 38mm thick acrylic platter scavenged off a Project rpm9.
Hope to have it ready for the next NEBO.:eyebrows:
Hope you don't change g'friends often or you will be too busy. There's quite a lot to like. I especially like what you have done with the tonearm. The VTA and bearings on the original arm are good and you have simply addressed the weaknesses - tube, wiring and maybe headshell. If I paid £1,000 for such a beauty it would be the biggest bargain ever. The platter is another problem area and I will be watching with interest what you come up with the Project project.
I wonder how that modded arm would be with a KAB fluid damper :hmm:
And why not. I love the skin job on this deck Ken.
brian2957
11-02-2016, 03:49
Very nice Ken . Are you bringing it to NEBO 7 :)
No, this one was a xmas present to my girl friend 2 years ago.
I just bumped these three build threads to help out a newbie to modding and show some of the things you can do.
Rich - She looks after it, still looks as good today.
Ali Tait
11-02-2016, 10:41
Nice job there Ken.
Dunno how on earth I missed this thread first time around, but (somehow) I did! :doh:
Utterly awesome work, Ken. The tonearm, in particular, is a revelation, which TBH alone you should consider offering as an upgrade service, charging appropriately for it, as when you consider what the Funk FX-1200 costs, which is essentially the same thing, whatever you produced would still be a bargain - and many Techy owners would love to upgrade their tonearms like this, whilst retaining the adjustability of VTA 'on the fly'....
It's a little sideline business we could set-up here for you, if you were interested, in the same way as Speedy Steve does with his armboards and counterweights, and Shuggie does with his collars for the Jelco. I have an idea how it would work - and if done right (in terms of promotion), there would be no shortage of customers. Just think how many SL-1200/1210 owners (and respective stock tonearms) there are out there!! :eek:
If you're interested, PM me and we can discuss the details :cool:
Anyway, threads and projects such as this are a credit to the AoS community, so give yourself a big pat on the back, mate! :thumbsup:
Just a couple of comments: given the attention to detail you undertook with this project, I'm surprised (unless I missed it) that you didn't address some of the inherent weaknesses of the stock platter, by applying some further damping?
One idea, if anyone else should decide to undertake this build, is to do as Technics have done with their new (ridiculously priced) £4k turntable, and that's bond a brass (or copper) plate to the top of the platter, covering its circumference, as well as adding some further damping underneath, both of which will help reduce resonance (the stock platter rings like a bell), and add some mass, which may provide some other benefits.
I'm pretty sure carrying that out would combine to provide some significant sonic gains :)
Also, (and I'm sure that you simply used it for photographic purposes), never *EVER*, use a felt/slip mat on Techy, or even the supplied rubber one, as it completely KILLS the sound! :nono:
Upgrading the stock mat and support feet are the first two things that everyone should do, when buying an SL-1200/1210, as those simple things alone (neither of which were designed for hi-fi purposes) can totally transform the sound of the turntable, and improve it dramatically.
Marco.
you should consider offering as an upgrade service.
Well, thanks but no.
Have a look at my workshop facilities and you will understand.
http://www.jkwynn.co.uk/Pics/My%20Worktable.JPG
Everything was made on this table in my kitchen, including the concrete deck! I don't have a garage or a shed.
I'm just not geared up for making more than what I do for myself. Also, I have enough ideas in the pipeline to keep me going till the end of the year as it is. For instance, the layout on the bottom left is for a six channel amplifier with built in active crossovers exclusively for the Yamaha NS-1000M. When I perfect my current crossovers they will be used in this project.
I get regular requests from folks all around the world, wanting me to make anything from regulator/PSU's to arm mods, deck/speaker veneering to new complete turntables, I don't take any of it on, I can't.
These projects are only scratching the surface of what I can do, given the right facilities. Half the battle (and fun) is finding ways of making things with what I can adapt/modify from off the shelf and with the basic tools that I have.
My background is in product design. I worked for the Pifco Group for ten years, which included Russell Hobbs, Carmen and Salton. When we were without a model maker, I used to make models of hair dryers, steam Irons and coffee makers etc good enough to photograph for the products advertising brochure and when the actual product wasn't available I did just that, on several occasions. This is where I picked up many of the skills that have transferred to this hobby.
Give me a lathe, milling machine and spray booth and I could really let rip. :D
Excuses, excuses! :lol:
Lol - no I see what you mean. However, it's probably more that, beyond simply for yourself as a hobby, you can't really be arsed, as if not, you'd *find* a way (where there's a will, and all that)..... But you have to WANT to do it.
I'm sure that 1000s of (now) successful businesses have produced products that were originally born on kitchen tables...! ;)
You didn't answer my point about the platter :)
Marco.
Done the numbers, no money in it on a commercial basis.
Remember I did this for a living for 30 years and have had my own company. Done some big budget projects with Jaguar etc, my tooling budget was nearly a million pounds a year with one company I worked for, so I know how to evaluate what is worthwhile pursuing.
This particular project answered the design criterion that I set out at the beginning, which was to make a simple cheap deck for my girlfriend. :)
I looked at one of the modified platters available at the time, from Inspire HiFi, but baulked at the price. After I had looked at what was available platter wise for this project. I decided instead to modify one that I had, to make it fit a Technics motor and that became deck No 3.
You were right about the mat, it was just to show the rotation, with the lettering.
I really like what you did to this turntable, great work! Also very impressed with the tonearm and would like to do the same. I was trying to find the same headshell as the one you used, but I am having a hard time to find it. Can a generic ADC headshell be used? Or would it be possible to have the Baerwald with a SME headshell that is in an angle like the AT-HS3? It would also make it possible (I hope) to use the SME connector. Or would that impact the weight too much?
You can use what ever headshell suits the geometry you want to use.
The offset angle of the cartridge is not an adjustable variable, it is determined by the Geometry type you choose.
The effective length and the spindle to pivot distance, combined with the null point radius, calculates an offset angle and overhang which are fixed.
It's best if the headshell angle is the same, or very close to this offset, so the cartridge sits square in the mounting grooves.
So start with your known elements and calculate the headshell angle you require.
I steer away from interchangeable headshells as its adding a connector in the delicate signal path, I run continuous leads from cartridge tags to phono stage, but that's my choice. The ability to swap cartridges easily may be more important for you, its almost irrelevant to me, as I can't afford to have multiple cartridges, I only use one cartridge and stick with it.
Note: The SME headshell has no offset angle, it is just a straight extension of the arm. The offset is created by the "S" shape of the arm, so you couldn't fit one to a straight arm.
I did another mod adding a Rega RB250 to the SL-1200 MkII. It might be worth a read regarding Baerwald/Technics geometry and note the calculator I used.
https://www.jkwynn.co.uk/Tech2_HTML/Tech2_14.html
The Spindle to Pivot distance on the SL-1200 means the effective length of the stock arm is not long enough for true Baerwald geometry, which leads to the cartridge being mounted at the end of the slots and twisted in the headshell. You have the opportunity to rectify both of these issues.
Ideally the Spindle to Pivot should be shorter, but that is very difficult to change on a std deck/arm.
Use the stock spindle to pivot distance in the calculator, use Baerwald Null points and see what effective length and offset angle are required to achieve these.
Find a headshell close to this offset angle, within 1 deg and cut your arm length to suit, the cartridge should mount in the centre of the headshell slots when the stylus tip is at the correct effective length, adjust the arm tube length until this lines up.
Use the Vinyl Engine data base to find a mass produced arm with the correct headshell offset and look for one of these headshells, used on ePay. This is what I did.
Thanks for your quick reply, I will start reading and calculating :)
You can use what ever headshell suits the geometry you want to use.
I did another mod adding a Rega RB250 to the SL-1200 MkII. It might be worth a read regarding Baerwald/Technics geometry and note the calculator I used.
https://www.jkwynn.co.uk/Tech2_HTML/Tech2_14.html
Just curious: when you compare the Rega RB250 to your DIY carbon SL tonearm, which one do you prefer?
The Rega was a replacement for my Carbon arm, which had been on three different decks I owned and was a used purchase anyway.
The bearings had worn out on the arm and I was having difficulty setting it up.
So the Rega arm was an improvement.
With the correct spindle to Pivot and effective length it sounds really nice using Baerwald alignment on an Ortofon 2m Blue. The Ebony armboard and isolation from the die cast plynth, the ebony board sits on Nylon spacers, seems to work. Several folks have said the Rega arms sound dull and lifeless on a Techie. I can only say that with my combination of armboard/geometry, counter weight, litz wiring and ancillary equipment, it sounds very nice, better than my DIY Carbon arm ever did and better than the stock Technics arm. Not massively better, but noticeable. I'm sure there are better arms to use, but I wasn't into spending a lot and picked up the used RB250 very reasonable, the Ebony arm board cost nearly as much. The main thing, is my Girlfriend, who I was doing the work for, is very pleased with the result, both in the way it sounds and looks.
I just repaired my SL tonearm that had worn/damaged bearings with new bearings (with MR52 miniature bearings), works very well. Could be useful for others as well? But working on it was looking at what could be improved and I think your mod will be very nice to add (and I can compare it to my default SL-1210 tonearm of my other sl-1210).
Anyway, I am trying to use the excel for calculating the effective length. If I understand correctly I can only add to the length a few mm since the pivot/spindle is set? So do I use it correctly if I add to the length until the pivot/spindle is about the fixed value from the default arm (215mm)?
See screenshot from attachment, does it make sense?
29169
I'm having trouble attaching this image in a more hi-res version, so als sharing it as a file: https://drive.google.com/file/d/1H7Azp2pLV6Hi7iVONBd59ZnkbFTdc_jK/view
Yes you've got it.....
Just alter values in the 3 yellow boxes.
Set the inner Groove to IEC value of 60.325 and outer Grove of 146.05.
With your fixed Spindle to Pivot distance on the Techie of 215mm, you need to adjust the effective length till this figure is achieved.
Set effective length to 232.82mm and this should show a S to P of 215.00mm.
The inner and outer Null points should show as 65.998 (66) and 120.891 (120.9) Baerwald figures to aim for are shown in brackets, so it is very very close to ideal.
The offset angle is 23.663 deg and overhang will be 17.816mm.
So a headshell of 23 to 24 deg offset will do the job with cartridge twist that is barely noticeable.
Many of the Linn tonearms use a headshell offset of 24 deg, which is why I used one. The Linn is only 0.337 deg from the ideal angle.
Look for one of these as a used item.
Yes you've got it.....
Just alter values in the 3 yellow boxes.
Set the inner Groove to IEC value of 60.325 and outer Grove of 146.05.
With your fixed Spindle to Pivot distance on the Techie of 215mm, you need to adjust the effective length till this figure is achieved.
Set effective length to 232.82mm and this should show a S to P of 215.00mm.
The inner and outer Null points should show as 65.998 (66) and 120.891 (120.9) Baerwald figures to aim for are shown in brackets, so it is very very close to ideal.
The offset angle is 23.663 deg and overhang will be 17.816mm.
So a headshell of 23 to 24 deg offset will do the job with cartridge twist that is barely noticeable.
Many of the Linn tonearms use a headshell offset of 24 deg, which is why I used one. The Linn is only 0.337 deg from the ideal angle.
Look for one of these as a used item.
Thanks for the detailed explanation, very helpful! I will start hunting for a Linn headshell. I also found some new ones/generic with ADC connector, but unclear what angle these were (and they looked very plasticky). I think for the time being I will use a Denon headshell (PCL-310BK; I guess angle of 20 degrees, not sure about overhang; I hope I can twist it the 4 degrees needed). I think with a Baerwald protractor this be visible and adjustable?
The carbon tubes arrived earlier this week, so I will share some pictures when I have time :)
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