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The Black Adder
12-05-2018, 08:31
Hi all.

I've recently been thinking of upgrading from my 3009 SII to a 3012 and wondered if anyone here has ever done the conversion?

I spoke to Johnnie of Audio Origami yesterday and he listed the parts I'd need but also recommended buying a one from scratch. As always J7's advice is taken with upmost appreciation and would always recommend his work, top man. :)

Yet looking at the prices of the 3012 it seems quite prohibitive for me. Also, the 3012 has to be around 85% identical to the 3009 so I'd only be buying the same arm again. (just trying to keep costs down)

So... Can anyone recommend a conversion? And would I get a reduced tracking error with a 3012?

Next question is armboard materials.

I'm currently using a Schopper arm board which is super but I've been looking at alternatives.

For example, I have a plywood board which looks lovely but is thinner than the Schopper so I have to use the VTA pillar adjustment even more which I don't like using as (I find) it detracts from the sound. To use the VTA pillar I like to set it as low as possible, even better with no adjustment but that even with the Schopper board isn't possible as the dashpot lift que lever thingie doesn't work.

Other materials I've been seaching for is Panzawood and also alluminium to which sounds interesting.

Obviously, I need to decide on a 12" tonearm before getting an armboard as they are different sizes.

Next question.

Has anyone used a spacer for the base of an SME arm? To get around adjusting the height of the tonearm I wondered if these are worth it?

Last question (maybe)

I use the SPU GT with my turntable and I use the standard Stevenson ortofon protractor. But looking on oldroadaudio.com I see there is a protractor for an SPU. Would it be better using this protractor?

https://assets.bigcartel.com/product_images/138294004/P1010129.JPG?auto=format&fit=max&h=1000&w=1000

Any help would be appreciated.

Jo :)

montesquieu
12-05-2018, 10:42
Lots of questions here first of all geometry - if you look at a cartridge in an SME headshell alongside an SPU you'll see that it puts the stylus tip in quite a different place to the SPU - quite a bit forward. So the geometry will be different and a protractor is essential if you want to use a 3012 for SPU. You will also need a heavier counter weight as the standard counterweight is not designed to balance out an SPU's 32g even on a standard 3009 never mind the slightly massier 3012.

Best suited to SPU is the Series 1 3012 as it's a genuinely high mass arm. But with the right counterweight, later ones can be used too though they are lighter and aren't quite so well matched. Either way the distance will differ from standard SPU distance (295 I think?) if you use a protractor to set it up for SPU. Adam (Westlower) recently set up a 3012 series 1 on his Garrard, I'm not sure what distance he ended up at.

I have all my other cartridges set for SPU distance so that I don't need to worry about geometry once it's set up, one of these is really handy for this https://www.ebay.co.uk/itm/TECHNICS-SFK0135-01-SL1200-SL1210-OVERHANG-GAUGE-CARTRIDGE-STYLUS-SET-UP-AID-/263109761017

The differences in sound between a 12in and a 9in arm are more than simply tracing error - in fact it's probably the least of the differences. With properly set up arm any audible difference in end groove between 9 and 12in won't be that much, if it's even detectale. But the 'feeling' is quite different. I'm running two Ikeda arms now on my TD124, a 9in and a 12in, otherwise more or less identical, and the differences are surprising - the 9in is faster, probably more detailed, has better timing; the 12in is more relaxed, has better ambience, the music feels slower. I thought that I would settle into a preference based on cartridges for each arm but actually I'm basing the preference more on musical genre and on what kind of listening I feel like doing.

Spacer - yes these work fine I used a 10mm aluminium one off ebay, there's a chap on either Audiogone or Vinyl Engine from Canada has made some lovely wood ones and has a few left - worth having a look.

Finally armboard - I've not been convinced that the angled armboard approach sticking out over the edge of the TD124 plinth, wide of the frame and of the mounting bolts, is necessarily a good way to go, I think a plinth made to accommodate a 12in arm will secure it much better (which is the route I went down and makes it possible to keep a 9in arm in the standard position). But I guess it's fine to try out how it sounds.

As for conversion kits ... these were quite widespread a few years back but I haven't seen much of them lately so have no view on that. I did think about it myself at one point. If you want to do the work yourself in might make sense but not sure about the economics if someone is putting it together for you, Series 1s are expensive but the later 3012s aren't too bad and the M2-12R which I had for a while looks the same but in my opinion is a better arm than the later 3012 can be had s/h for not much over 1k.

WESTLOWER
12-05-2018, 18:28
Just to confirm the spindle to pivot distance
On the 3012 using an SPU is 303mm
This is different to the much published distance knocking around.
Tom kindly helped set it up using the Dr. Fieckert set up protractor
tool and we know it's correct as it sounds fabulous.

The Black Adder
13-05-2018, 06:07
Thanks for taking the time with your reply, Tom. :)

Do you think the special Ortofon SPU alignment template is a good thing to have or is the standard Stevenson one I have okay?

I've always struggled aligning the SPU with the template due to it's curved sides, so a best guess and most importantly 'time' has always been the ticket.

So, lets say I stick the 3009 arm, do you recommend the Dr. Feickert protractor for that?

Trying to get the alignment of the 3009 has always been a bit hit and miss for me. I could do with getting it nailed.

There are plenty out there who have decided that the 3009 on the TD124 is simply not good enough but once set up it's a great sounding arm. IGD is sometimes (but not always) a problem hence why I could do with finally nailing the solution.

This may lead to getting a more adaptive armboard such as the one from audioclassique (http://audioclassique.com/page3.html) which has a little more adjustment room for the 3009.

Good idea?

The Black Adder
13-05-2018, 06:08
Just to confirm the spindle to pivot distance
On the 3012 using an SPU is 303mm
This is different to the much published distance knocking around.
Tom kindly helped set it up using the Dr. Fieckert set up protractor
tool and we know it's correct as it sounds fabulous.

Thanks adam.

Yes that tool does look very good.

WESTLOWER
13-05-2018, 08:42
I think spindle to pivot may differ on versions of SME3012, just to add more
Confusion!

The Black Adder
13-05-2018, 13:11
Lol... I'll just stick with the 3009 then... Lol

Sent from my 9001X using Tapatalk

montesquieu
13-05-2018, 16:16
Sorry had guests this weekend ... would recommend the Dr Freickert for sure. With an SPU you can't change the offset anyway (so in that regard the curved sides don't matter really) ... the main thing is to find the spindle to pivot distance that works best and puts the stylus tip in the right place.

A dedicated protractor for SPU with SME 3009/3012 (assuming the right version is selected and the the correct SPU stylus distance from headshell base is put in the calculation might give you more to work with, but the Dr Freickert is just so useful for establishing and fine-tuning spindle to pivot that I generally use it as my primary tool. I do have some custom protractors from the guy on ebay but it's not always easy to ensure they are in the correct alignment to the pivot centre, unlike the Dr Frecikert where the's no ambiguity (so long as it's clear where to point to as the pivot centre on top of the arm).

BTW I couldn't remotely argue that the 3009 isn't good enough for SPU, yes in theory the numbers don't crunch ideally in terms of resonance but I've heard both 3009 and 3012 sounding very good indeed with SPU.

Barry
13-05-2018, 17:15
Thanks for taking the time with your reply, Tom. :)

Do you think the special Ortofon SPU alignment template is a good thing to have or is the standard Stevenson one I have okay?

I've always struggled aligning the SPU with the template due to it's curved sides, so a best guess and most importantly 'time' has always been the ticket.

So, lets say I stick the 3009 arm, do you recommend the Dr. Feickert protractor for that?

Trying to get the alignment of the 3009 has always been a bit hit and miss for me. I could do with getting it nailed.

There are plenty out there who have decided that the 3009 on the TD124 is simply not good enough but once set up it's a great sounding arm. IGD is sometimes (but not always) a problem hence why I could do with finally nailing the solution.

This may lead to getting a more adaptive armboard such as the one from audioclassique (http://audioclassique.com/page3.html) which has a little more adjustment room for the 3009.

Good idea?

The alignment protractor used depends on the arm in use and not vice versa, since the protractor is used to display the two radii where the angular tracking error is exactly zero. These two null-radii are in turn determined by the geometry of the arm that has been chosen by the designer.

For the Series I and Series II SME arms, the inner null-radius is set to 60.3mm; since it was known that the distortion due to deviation from true tangential tracking varied inversely with radius. Hence to minimise 'end of side' distortion, the inner null-radius was set to be the same as the innermost groove radius. This radius was independent of arm length, which is why changing a 9" SME arm to one of 12" effective length will not improve end of side distortion, but will reduce tracking error distortion elsewhere by a factor of 9/12. So in your case use the alignment protractor that came with SME arm.

The Ortofon protractor shown corresponds to the Baerwald arm geometry with null-radii at 66mm and 121mm. Since it is impossible to adjust the offset angle when using an SPU in an SME arm, the only degree of freedom you have at your disposal to adjust the overhang through use of the sliding bedplate, thus it will not be possible to achieve zero tracking error at both of the null points.

It seems all Thorens 124 armboards vary as to where the arm mounting slot for the SME arm has been cut. I have four SME armboards and they are all slightly different. The only advantage of using the modified arm board you mention, is if you are finding that in order to achieve the correct overhang you have to push the arm back to the rear limit of the bedplate.



On a slightly different aspect, you mention difficulty in counterbalancing your SPU when mounted in an SME Series II/S2 arm. I have had no trouble counterbalancing modern SPUs in my SME arm, but did find that when I tried your SPUGTE in my arm (Peter sent it to me to correct an intermittent connection, before he sent it on to you), I found the arm counterweight needed to be placed precariously close to the end of the arm stub. In the end I replaced it with the counterweight from a 12" SME, but suggest you try to use a set of stylus scales, so that with the rider weight set at 'zero' the cartridge is counterbalanced so that the VTF is 4g. That way the counterweight won't be too far back near the end of the arm stub, and you still have the freedom to reduce the VTF to < 4g by moving the rider weight forward.

The Black Adder
13-05-2018, 18:22
The alignment protractor used depends on the arm in use and not vice versa, since the protractor is used to display the two radii where the angular tracking error is exactly zero. These two null-radii are in turn determined by the geometry of the arm that has been chosen by the designer.

For the Series I and Series II SME arms, the inner null-radius is set to 60.3mm; since it was known that the distortion due to deviation from true tangential tracking varied inversely with radius. Hence to minimise 'end of side' distortion, the inner null-radius was set to be the same as the innermost groove radius. This radius was independent of arm length, which is why changing a 9" SME arm to one of 12" effective length will not improve end of side distortion, but will reduce tracking error distortion elsewhere by a factor of 9/12. So in your case use the alignment protractor that came with SME arm.

The Ortofon protractor shown corresponds to the Baerwald arm geometry with null-radii at 66mm and 121mm. Since it is impossible to adjust the offset angle when using an SPU in an SME arm, the only degree of freedom you have at your disposal to adjust the overhang through use of the sliding bedplate, thus it will not be possible to achieve zero tracking error at both of the null points.

It seems all Thorens 124 armboards vary as to where the arm mounting slot for the SME arm has been cut. I have four SME armboards and they are all slightly different. The only advantage of using the modified arm board you mention, is if you are finding that in order to achieve the correct overhang you have to push the arm back to the rear limit of the bedplate.



On a slightly different aspect, you mention difficulty in counterbalancing your SPU when mounted in an SME Series II/S2 arm. I have had no trouble counterbalancing modern SPUs in my SME arm, but did find that when I tried your SPUGTE in my arm (Peter sent it to me to correct an intermittent connection, before he sent it on to you), I found the arm counterweight needed to be placed precariously close to the end of the arm stub. In the end I replaced it with the counterweight from a 12" SME, but suggest you try to use a set of stylus scales, so that with the rider weight set at 'zero' the cartridge is counterbalanced so that the VTF is 4g. That way the counterweight won't be too far back near the end of the arm stub, and you still have the freedom to reduce the VTF to < 4g by moving the rider weight forward.

Hi Barry.

In bold... Today I've been trying to do this again on my new armboard and this is exactly what I'm finding. I can't seem to get the correct overhang and at the same time get the SPU to align with the inner null point of the Stevenson protractor. I have to pull the arm forward to align it sending the other setting out.

So I'm wondering if the hole is correctly cut on the arm board.

Counterbalancing seems to be nailed . I can balance out to 4g but both counterweights and both rider weights are closer to the pivot than the stub end of the arm... does that sound correct?

The Black Adder
13-05-2018, 19:05
Sorry had guests this weekend ... would recommend the Dr Freickert for sure. With an SPU you can't change the offset anyway (so in that regard the curved sides don't matter really) ... the main thing is to find the spindle to pivot distance that works best and puts the stylus tip in the right place.

A dedicated protractor for SPU with SME 3009/3012 (assuming the right version is selected and the the correct SPU stylus distance from headshell base is put in the calculation might give you more to work with, but the Dr Freickert is just so useful for establishing and fine-tuning spindle to pivot that I generally use it as my primary tool. I do have some custom protractors from the guy on ebay but it's not always easy to ensure they are in the correct alignment to the pivot centre, unlike the Dr Frecikert where the's no ambiguity (so long as it's clear where to point to as the pivot centre on top of the arm).

BTW I couldn't remotely argue that the 3009 isn't good enough for SPU, yes in theory the numbers don't crunch ideally in terms of resonance but I've heard both 3009 and 3012 sounding very good indeed with SPU.Thanks Tom... Then the protractor is on the list.[emoji4] Thanks very much.

Can you understand where I'm coming from regarding the overhang and correct alignment?

[emoji3]

Sent from my 9001X using Tapatalk

Barry
13-05-2018, 19:07
The curved sides of the whale-shaped Ortofon G headshell doesn't make it easy to check that the sides of the headshell are exactly parallel to the lines of the alignment protractor when the stylus is located in the centre point. But this is exactly what you have to do. You have to look vertically down on the headshell and assess whether the sides of the headshell, at its widest point, are tangential to the lines on the protractor. Not easy, but can be done with patience.

I don't understand what you mean by not being able to achieve correct overhang and at the same time achieve alignment using the protractor. They are one and the same: if you can achieve alignment using the protractor, you have achieved the correct overhang. Are you finding you have to slide the arm too far forward? In that case, maybe the armboard you mention could help as it allows the slot of the SME sliding bedplate to lay closer to a notional radius from the turntable spigot, thereby increasing the range of overhang adjustment. You may have seen Thorens armboards cut so that the slot is parallel to the side of the TT. These may look aesthetically more pleasing to the eye, but limits the available range of adjustment.


Apropos the position of the counterweight assemby - the closer to the pivot point the better, so what you have achieved in your situation is fine.

The Black Adder
13-05-2018, 19:30
Hi Barry. Well, the recommendation for the SPU overhang is 16mm.. Although I don't have a tool to exactly measure it (yet) it just doesn't look right... Hope that makes sense.

Your right about the arm board.. The straight cut sme hole does look correct... My Schopper one is slanted while the ply wood one is straight.

I'll have another go tomorrow with the straight cut board.

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montesquieu
13-05-2018, 19:48
Thanks Tom... Then the protractor is on the list.[emoji4] Thanks very much.

Can you understand where I'm coming from regarding the overhang and correct alignment?

[emoji3]



I would express it a little different from Barry though I know what he means .. you don't have control over adjustment of overhang using the normal methods (twisting or adjusting the position of the cartridge in the headshell) so all you have to work with is the spindle to pivot distance, which then delivers the best alignment you are going to get. It's true that every protractor is custom but I find that adjusting the spindle to pivot distance with the Dr Freckert enables me to set the overall distance so that SPU tip then generally comes into close alignment with the curve generated by custom protractors, usually to within a mm or so, and that can be fine-tuned with the custom protractor, if you have confidence that it's 100% accurate (something I'm often skeptical about). What I use the custom protractor for mainly is to ensure an appropriate degree of twist on non-SPU cartridges, as I generally keep to SPU collet to stylus tip distances for all my cartridges.

Actually I tend not to get too uptight about these things, it seems to me that 1mm or so out at inner or outer groove or at specific points on a protractor curve is going to make relatively little audible difference when you compare the much larger impacts of different geometries and null point assumptions - the fixed nature of an SPU means it's unlikely to be 100% perfect on every arm at the 'official' spindle to pivot distance (though as it happens, it is on my Ikeda IT-345 CR1 at precisely 230mm, and comes in nicely on the (much older) Ikeda IT-407 if I set it back a fraction over 1mm from the quoted distance).

Also (and I'm always hesitant to disagree with Barry on any topic!) but I'm not entirely sure it's worthwhile to focus on the sides of the headshell when adjusting an SPU ... if you look at an SPU from underneath, the cartridge angle within it is very slightly offset within the headshell, so the sides aren't telling you the exact alignment anyway - another reason mainly to focus on the placement of stylus tip.

montesquieu
13-05-2018, 19:54
Hi Barry. Well, the recommendation for the SPU overhang is 16mm.. Although I don't have a tool to exactly measure it (yet) it just doesn't look right... Hope that makes sense.

Your right about the arm board.. The straight cut sme hole does look correct... My Schopper one is slanted while the ply wood one is straight.

I'll have another go tomorrow with the straight cut board.

Sent from my 9001X using Tapatalk

Just been looking at tools, effectively I use the Dr Freckert as a '1 point' tools to place the stylus correctly and fine-tune the spindle to pivot distance from the quoted figure. The Project one is reasonably priced and also uses a '1 point' approach https://www.ebay.co.uk/itm/Pro-Ject-Project-Align-IT-Cartridge-Alignment-Tool/172355014327?epid=1174723516&hash=item282128ceb7:g:iN0AAOSw~AVYpd~V

REXTON
13-05-2018, 20:09
Just to confirm the spindle to pivot distance
On the 3012 using an SPU is 303mm
This is different to the much published distance knocking around.
Tom kindly helped set it up using the Dr. Fieckert set up protractor
tool and we know it's correct as it sounds fabulous.

Thats very strange. Mines 295mm I use Fieckert as well and currently sport a Silver Meister I SPU. :scratch:

Barry
13-05-2018, 20:10
Ignore the 'recommended' overhang for the SPU; you're not using it in an Ortofon arm, you are using it in an SME arm.

The overhang and offset angle are solely related to the arm alone and not to the cartridge being used. Both variables are determined by three quantities: the effective arm length (the distance between the stylus and the arm pivot point in the horizontal plane) and both the innermost and outermost groove radius of the record.

Just use the SME alignment protractor, and get the sides of the SPU headshell parallel to the lines of the protractor when the stylus is at the point marked, by adjusting the overhang (which is all you can do) with the sliding bedplate of the SME arm.




http://theartofsound.net/forum/showthread.php?20109-Tonearm-alignment

The Black Adder
13-05-2018, 20:24
Aaah... Ah, hahaaaa. Lol... Didn't know that Barry regarding the overhang being only with an ortofon Arm...

Doh!

Gotcha... I'll just align it.

I think I'll try the protractor though.. Always handy.

I do fancy an ortofon arm BTW... They are supposed to be nice.



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Barry
14-05-2018, 00:38
I think we are in danger of over-worrying about all this. Arm/cartridge alignment for a pivoted arm is a compromise at best; and one can argue as to which approach is 'optimum' if, indeed, any are.

As I showed in the piece I wrote for The Knowledge (cited above), with two degrees of freedom at the designer's disposal (the overhang and the offset angle), one can always arrange for there to be two points on the record surface where the tracking error is zero. Where those points are, and how the distortion is distributed away from those points is a matter of choice. There are three recognised approaches: those analysed by Baerwald, Loefgren and Stevenson, each having a different criterion of optimisation.

To complicate matters further, British arm manufacturers of the '60s simply designed their arms to place one null radius at the innermost groove radius. They didn't consider where the second null radius would be; which is why the accompanying alignment protractor only has one radial point marked. If one can ascertain the effective length of the arm and make an assumption of the inner and outer radii of the record surface, then one can calculate where the two null radii will lay.

So rest assured, regardless of which alignment protractor you use, you will always be able to set up the arm overhang (either by moving the cartridge in the headshell, or by adjusting the arm pivot to TT spigot distance (since overhang = effective arm length - pivot to spigot distance), to place a null radius at one of the chosen points. There will always be a second null radius somewhere on the record surface, but as I have said, whether or not this corresponds to an optimum arrangement is a matter of debate

In general most modern British arms are designed to follow the Baerwald approach (certainly the SME IV, V and their 'M' series, as well as the 'Improved' 3009 having late serial numbers). Japanese arms tend to follow Stevenson's approach, but choose a different figure for the innermost groove radius.

struth
14-05-2018, 02:14
Try a mofi geo-disc.

montesquieu
14-05-2018, 09:04
I think we are in danger of over-worrying about all this. Arm/cartridge alignment for a pivoted arm is a compromise at best; and one can argue as to which approach is 'optimum' if, indeed, any are.

...

So rest assured, regardless of which alignment protractor you use, you will always be able to set up the arm overhang (either by moving the cartridge in the headshell, or by adjusting the arm pivot to TT spigot distance (since overhang = effective arm length - pivot to spigot distance), to place a null radius at one of the chosen points. There will always be a second null radius somewhere on the record surface, but as I have said, whether or not this corresponds to an optimum arrangement is a matter of debate


Totally agree with this and tallies with my comments in post #14.


Thats very strange. Mines 295mm I use Fieckert as well and currently sport a Silver Meister I SPU. :scratch:

It's very complicated ... it seems SME were utterly inconsistent with their effective length and spindle to pivot on this series, there was a thread a long time ago http://theartofsound.net/forum/archive/index.php/t-22395.html

WESTLOWER
14-05-2018, 10:15
Thats very strange. Mines 295mm I use Fieckert as well and currently sport a Silver Meister I SPU. :scratch:

yes i checked, defo 303mm.:scratch:
I think there is some variation on the models. As I understand it I have the 3012 mk2 (we initially thought it was the Mk1 but it has a one piece main counterweight and i believe from research that the Mk1 had a 2 piece main counterweight, not including the separate rider weight)

As i said I think there is a grey area to which is what on models and then we can only come to the conclusion different models
have varied spindel to pivot distances. Confused... you will be!

Barry
14-05-2018, 11:00
It's very complicated ... it seems SME were utterly inconsistent with their effective length and spindle to pivot on this series, there was a thread a long time ago http://theartofsound.net/forum/archive/index.php/t-22395.html

There is no fixed spindle to pivot distance with an SME arm, because of the sliding bed plate used. Without getting out the installation protractor which allows one to mark out and cut the arm base slot and measure the distance from the centre of the spindle hole to the centre of the arm base slot, I can't quote the figure. But whatever it is, unless the slot is poorly positioned on the arm board, it is largely irrelevant as this distance is adjusted in order to achieve the correct overhang.

Early SME arms were certainly inconsistent with their geometry, as can be seen by looking at the vinylengine.com database. They even changed the geometry midway through the production of the 3009 (Improved) arm; with arms having later serial numbers conforming to the Baerwald geometry. SME now consistently conform to Baerwald for all subsequent models.

I'm still mystified as to why SME deviated from the 52mm stylus to headshell flange distance of the SPUs when they introduced their own headshell, unless they thought the 2mm difference would simply be absorbed within the +/- 12.7mm compass of the sliding bedplate adjustment.

montesquieu
14-05-2018, 11:09
I'm still mystified as to why SME deviated from the 52mm stylus to headshell flange distance of the SPUs when they introduced their own headshell, unless they thought the 2mm difference would simply be absorbed within the +/- 12.7mm compass of the sliding bedplate adjustment.

Yes this really annoyed me too when I had an SME 12in arm (M2-12R) as it meant there could be no co-existence between SPU and SME headshells without completely resetting the arm on each change as a result the SME headshells stayed in the box.

Barry
14-05-2018, 11:29
yes i checked, defo 303mm.:scratch:
I think there is some variation on the models. As I understand it I have the 3012 mk2 (we initially thought it was the Mk1 but it has a one piece main counterweight and i believe from research that the Mk1 had a 2 piece main counterweight, not including the separate rider weight)

As i said I think there is a grey area to which is what on models and then we can only come to the conclusion different models
have varied spindel to pivot distances. Confused... you will be!

The Mk. I SME used a very thick bedplate as well as 'tall' locking nuts, compared with those parts of the Mk. II arms. The Mk. I also had a very wide adjustment of azimuth, allowing the headshell socket to be rotated at least 45 degrees so that EMT/Neumann cartridges could be used. The Mk. I's also used a different 5-way connector at the arm base, whereas the Mk. IIs used a modified 4-way Belling & Lee 'Unitor' connector.

In those days, there was no standardisation of the position of the stylus relative the to cartridge fixing. So the designation 9" or 12" was only notional. The original SME arm was designed by ARA for his own use and with Ortofon SPUs in mind (that is why SME adopted Ortofon's headshell coupling, and originally the arm was sold without a headshell; that came later as an optional extra), the effective arm length was not quoted at all. Likewise the spindle to pivot distance was only nominal because this distance is adjusted to achieve the desired overhang, where again in those days, the only concern was to achieve a null-point at the end of a 12" diameter record, to try and minimise end of side distortion.

WESTLOWER
14-05-2018, 12:02
The Mk. I SME used a very thick bedplate as well as 'tall' locking nuts, compared with those parts of the Mk. II arms. The Mk. I also had a very wide adjustment of azimuth, allowing the headshell socket to be rotated at least 45 degrees so that EMT/Neumann cartridges could be used. The Mk. I's also used a different 5-way connector at the arm base, whereas the Mk. IIs used a modified 4-way Belling & Lee 'Unitor' connector.

In those days, there was no standardisation of the position of the stylus relative the to cartridge fixing. So the designation 9" or 12" was only notional. The original SME arm was designed by ARA for his own use and with Ortofon SPUs in mind (that is why SME adopted Ortofon's headshell coupling, and originally the arm was sold without a headshell; that came later as an optional extra), the effective arm length was not quoted at all. Likewise the spindle to pivot distance was only nominal because this distance is adjusted to achieve the desired overhang, where again in those days, the only concern was to achieve a null-point at the end of a 12" diameter record, to try and minimise end of side distortion.

Great information Barry, thank you.

The Black Adder
15-05-2018, 09:28
Up and running in my new plinth.. Lookin' and sounding great. [emoji7]

Some pics with the Schopper arm board and some with the matching ply wood arm board.

Currently running with the Schopper but the matching arm board looks lovely too.

https://uploads.tapatalk-cdn.com/20180515/58cd923f439781785cb39ecc84557df9.jpghttps://uploads.tapatalk-cdn.com/20180515/ebaf5a037439afccf8ed3ba50e5847ba.jpghttps://uploads.tapatalk-cdn.com/20180515/08f3f1cf3feb383c165e6e4cc4502f6d.jpghttps://uploads.tapatalk-cdn.com/20180515/b5807233ebd987ebf0e669eb92e3470a.jpg

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montesquieu
15-05-2018, 09:55
Looks fab!

WESTLOWER
15-05-2018, 12:06
lovely!! well done.

The Black Adder
15-05-2018, 15:30
Thanks guys [emoji16]

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