SME 3009 S2 coupling rubbers

[southern_tango]

Hello everybody, quick question, where could I buy replacement coupling rubbers for a SME 3009 S2 non improved as in  my recently acquired one, they are perished?

Tried to check on multiple posts but couldn't find anywhere in Australia, apart from apparently someone used to sell a Teflon replacement, and most places overseas, with money exchange and freight charges there price is pretty steep.

As always any advice/ info will be greatly appreciated.

[rovellas]

I see you're getting no replies here.   I too have wondered the same thing in the past.

The reply I got from an experienced hifi dealer I visited in person was to just forget about the rubber couplers and just screw the arm mount plate hard down to the armboard / deck of the turntable.  
This advice didn't completely satisfy me I confess, although I could see that it made sense for some decks.

I think that the answer may be to go to SME themselves - https://www.smetonearms.com/index.php?main_page=product_info&cPath=3_10&products_id=3
 

Not even expensive - for them.

 

[rovellas]

55 minutes ago, rovellas said:

I think that the answer may be to go to SME themselves - https://www.smetonearms.com/index.php?main_page=product_info&cPath=3_10&products_id=3
 

Ah but that's my mistake - that link is for a 3rd-party company in the US that I have heard good things about.   USD$15 for a set of mounting grommets seems cheap tho

SME themselves no longer seem to list any spares on their website - back when they did, they seemed to hold a very deep range of near-antique parts as available to order.
But now, I guess you'd need to email service@sme.ltd.uk, and ask.

[Warren Jones]

Ditch the rubber grommets, they allow the TA to move microscopically. Every SME I have installed I don't use the rubbers, I screw the mount directly to the TT or arm board with washers under the screws.

[southern_tango]

I guess that I didn't explain myself properly, my problem was the coupling rubber that sits inside the stem of the counterweight between it and the arm tube.

It has a tendency to perish and the counterweight and slide weight gets loose ( a bit hard to see in the pic)

Problem is ,there is no one that stocks those parts here in Australia and so far the closest one is direct from SME.

Also I thought by now should be a better solution than rubber as we are talking around 50 years difference and upgrades should been developed for such a popular tonearm...  as replacing the old connectors with RCA terminals to use different cables...

As with the grommets ,it should be 3mm rubber grommets or rubber O rings to replace them...

[aussievintage]

 

Just now, southern_tango said:

I guess that I didn't explain myself properly, my problem was the coupling rubber that sits inside the stem of the counterweight between it and the arm tube.

 

Yes, I thought they were on the wrong track.    On an old arm, I wound some plumber's teflon tape onto the spike, until it was a firm fit for the counterweight.  I know that alters the resonance as the teflon is firmer than the rubber, but in practice it seemed to work well.

[southern_tango]

4 hours ago, aussievintage said:

 

 

Yes, I thought they were on the wrong track.    On an old arm, I wound some plumber's teflon tape onto the spike, until it was a firm fit for the counterweight.  I know that alters the resonance as the teflon is firmer than the rubber, but in practice it seemed to work well.

I have seen a pic of one like that the other day.

[southern_tango]

I was thinking maybe to 3D print the coupling , in one piece using TPU as it is flexible.

Did a sample on PLA to get an idea and recon it is doable ( even with my cheap pos printer)

Now question time:

 

Does a more solid coupling affect the the resonance of the arm as for example the S2 improved is solid instead of a rubber core?

 

Did anybody try the Teflon version of the coupling?

 

Does the difference in weight of the couplings affect the tonearm?

 

Could using a non original part hurt the performance of the arm?

And it's value?

 

So, the most important question

Should I order the part from SME or try my 3D printed version?

 

BTW a couple of pics of my RCA terminals, please don't shoot me...

 

 

 

[aussievintage]

6 minutes ago, southern_tango said:

Should I order the part from SME or try my 3D printed version?

 

I'd try your own 3D printed one

[rovellas]

8 hours ago, aussievintage said:

Yes, I thought they were on the wrong track.

Apologies for misunderstanding. 

The coupling rubbers are also available seems - at the same smetonearms.com US site I mentioned earlier.

But yeh the teflon 3D printed DIY sounds the more exciting prospect if you can do it, and it sounds like perhaps you can.

I have an S2 improved but have never had the back of it off to inspect it.

Those RCA terminal mounts look good !

[southern_tango]

2 hours ago, rovellas said:

Apologies for misunderstanding. 

The coupling rubbers are also available seems - at the same smetonearms.com US site I mentioned earlier.

But yeh the teflon 3D printed DIY sounds the more exciting prospect 

 Unfortunately my parts are going to be TPU, which is plastic but flexible, if that fails, got a quote from SME for £29 for them posted, which is the cheaper I have seen but, again it is a bit to much for two little pieces of rubber and as I said it surprised me no one came with a better solution.

Your S2 improved doesn't have that problem the counterweight runs on the extension while the sliding load weight is supported by a spacer ( no idea of material) that is what gives me the idea of how necessary is the rubber to decouple vibrations.

[Warren Jones]

17 hours ago, southern_tango said:

Does a more solid coupling affect the the resonance of the arm as for example the S2 improved is solid instead of a rubber core?

 

Did anybody try the Teflon version of the coupling?

 

Does the difference in weight of the couplings affect the tonearm?

 

I would opt for the rigid coupling of the CW stub, decoupling the stub so it can move is a bad idea as the CW can then resonate and it's the tail wagging the dog.

 

These plots are of a Technics EPA-100 with OEM CW setup which has a weight in oil inside the CW that wags. The first plot is completely stock and the second plot is a new rigidly mounted CW and stub.

 

Note the massive reduction in CW induced sidebands at 8.5Hz. This was significantly audible as improved imaging and detail.

 

Those 8.5Hz sidebands at -47.8dB down will be present on every musical note, and -47dB is audible.

 

Edited January 21, 2024 by Warren Jones

[southern_tango]

Those graphs are pretty interesting Warren Jones ,  I still don't understand why they used the coupling rubbers while nearly all the tonearm wand go from the headshell connector to the CW and some even the headshell is part of the wand.

Let's see when I get the TPU filament ( guess it is going to be 100% infill ) .

Don't want to risk damaging the tonearm otherwise would try PLA  in different infills to see if there is any difference.

Or thinking about it, if ever finish fixing my lathe could have used Teflon or delrin both with interesting properties...

Edited January 22, 2024 by southern_tango

[aussievintage]

8 minutes ago, southern_tango said:

Those graphs are pretty interesting Warren Jones ,  I still don't understand why they used the coupling rubbers while nearly all the tonearm wand go from the headshell connector to the CW and some even the headshell is part of the wand.

 

Indeed, it would be nice to know why SME mounted the counterweight on rubber couplers.   I would hesitate to conclude that they didn't know what they were doing  , and a rubber coupler is very different to  weight in oil.

 

SME made fixed headshells as well as bayonet mounted btw.  The main thing was to reduce mass IIRC.

[southern_tango]

3 minutes ago, aussievintage said:

 

Indeed, it would be nice to know why SME mounted the counterweight on rubber couplers.   I would hesitate to conclude that they didn't know what they were doing  , and a rubber coupler is very different to  weight in oil.

 

SME made fixed headshells as well as bayonet mounted btw.  The main thing was to reduce mass IIRC.

They could have done a full length wand as blade pivot can screw on top anyway...there must be a reason, for sure but that is beyond my knowledge or intellect

[Powerglide]

I purchased a set from the link @rovellas posted, came out of Canada $50AUD landed. Get a new set of grommets for the mount as well, I’m in the camp that they are important for isolation (depending on your TT and plinth) 

[southern_tango]

Well, I got the TPU filament and made the coupling, instead of a 2 pieces, I made it only one but with a recess so the front and tail makes contact with the external tube.

Fitment was tight , so I think, no glue was required and only visible difference is in the spacing ring, hopefully I didn't ruin the performance of the tonearm with my idea.

[aussievintage]

Looks good.  I am sure it'll work well.