SME V arm: dynamic VTF or straight weight


I am using an SME V arm and wonder if anyone has compared the sound using the dynamic VTF (i.e. setting the dial to 2.0g) versus setting the dial to 0.0g and simply using the counterweight and an accurate scale to set VTF at 2.0g. Is there a sonic difference and what is the theory behind one versus the other?

I would think that using the latter method moves the counterweight closer to the arm's pivot point and effects how the bearing is loaded and possibly also the moment of enertia of the arm.

I have briefly tried to hear a difference, but couldn't and plan to do a more controlled comparison. Anyone's own experience would be appreciated. Thanks.

Peter
peterayer
Hi Peterayer

>>> The biggest problem with the SME V design is the difficulty of adjusting height. Every time I try it, the arm column moves slightly out of vertical because the VTA screw is off centre and I have to recheck azimuth <<<

My solution:
Make some hardwood spacers (small oblong blocks) fit between armrest and clamping assembly, loosen the bolts press down on the pivot bearing-bridge. The arm will ALWAYS be level with the spacer block. I have made these according to VTA requirement. I started somewhere from 1/2" which fits for a Windfeld. If the PC-1 is by X taller this must be added.
You can achieve quite easily the small differences Raul is talking about --- AND HE IS RIGHT THERE --- a 0.3mm difference can just make that difference to be more pleasing.

Greetings,
Axel
Hi all,
one thing came to mind when reading about silicone damping being considered a 'crutch' to make up for lack of arm to cart matching ---- but wait, there are arms that use 'damping' a their required part of operation!
Well Tempered (now a golf ball! in silicon), Schroeder uses a magnet, just to mention two. Others consider it an 'option' but actually seem to sound more 'right' with juice in their various bowls, I'm thinking of uni-pivoted designs.

Are these all aberrations to some 'true teaching' , I can not see that, honestly.

Back to the V damping trough, (an option with the less expensive IV, IV.vi, and 300 series). If you have a V, and feel like some purists, and want to remove it --- it leaves the arm with a rather unbalanced looking uncovered left side horizontal pivot bearing...
I listened with that 'hard wear' on and off --- ZERO difference.
I might mention it is not quite that easy to take it off in the first place, since it it VERY solidly bolted on, with some part catching under some other cover. Just before you get the idea.

Axel
Axel,
I agree with you about removing the SME V damping trough. I removed it for cleaning as per the SME instructions and then reinstalled it for aesthetic reasons. I can't imagine there being any sonic difference one way or the other. I don't think that "some purists" are using their arms with the trough removed, or at least I have'nt read of any. I think they just don't fill it with silicone. My silicon had become somewhat hard and I simply wanted to clean it out.

It seems to me that SME designed the damping trough for some sonic reason. They do not mention that it should be used when there is a cartridge/arm mismatch but this is territory that I know nothing about. Daniel's point about it being used to dampen resonances created by a cartridge/arm mismatch does make sense. I have not done a careful listening test. I wonder if this is about relative catilever movement between low versus high compliance cartridges and the stability of the arm moving across the LP.
Hi Peterayer
:-) nice to hear you are not A -purist- :-)

I think you got it pretty well down, in my estimate, by your comment:
>>> I wonder if this is about relative cantilever movement between low versus high compliance cartridges and the stability of the arm moving across the LP. <<<

Some notion I will share:
Look what your stylus is doing when being lowered into the start groove ---- pop - and wiggle, sometimes jumping quite nastily into the first music groove, ever had that?
Well, I do. Now the lower the compliance the less this seems to be the case. Why? Well, that another subject I guess.
Your PC-1 has 10CU compliance, I had a Dorian (now my son's) with 12CU, but I also had a Jubilee, and now Windfeld both 16CU.
The higher the compliance the more wiggle and jump, at least so far as to my experience.
Now, use just the smallest amount of damping you will find that this sort of disturbing effect is much reduced.

But now what about the sound?
Well, with a higher compliance cart it seems to be beneficial preventing some treble 'overshoot'. Do too much, the cart will very quickly sound kind of dull. The difference in my (and other's experience) is often not more than 1/8 turn up or down.
Want to call that a fix for a mismatch, fine by me. But I think it's just an additional tuning facility you either decide works for a cart or not, so you just deactivate it.

Same as to the varying levels of anti-skate.
So go ahead, tell me, that if I need anti-skate it's due to a arm/cart mismatch?! well I'm honestly not on that side, I simply use it, BUT with discretion.

It's a bit like the down-haul tension on a sail. There is no one tension fits all, now is there, ever?

So far my thoughts on the subject.
Greetings,
Axel