Seems like I have figured out a way to barely tilt the assembly up a little by loosening the screws at the base of the rails. This seems to have eliminated the brushing issue, now to see whether the mistracking is reduced. Guessing I may have to correct azimuth soon to.
SME 312S issue
Have a vintage SME 312S arm mounted on a Technics SP10 MKII sitting in a Porter Plinth with a Kiseki Purple Heart cartridge and I and all others that listen to it hear mistracking at times in the final third of most standard LPs. Since it is happening on just about every record I do not believe that this is solely inner groove distortion. The most common theory(since the arm and cartridge was set up by one expert and then adjusted by another) is that upon close inspection, the bottom of the arm tube may be brushing against the top of the arm lift. The lift has been adjusted so that it can go no lower and I can find no information that seems to show that the arm can be adjusted independently of the lift(they seem to share the same platform). When a light is placed behind the platform and shone toward a viewer the gap seems smaller when the cart is down on a stationary record near the end than compared to the gap visible when the cart is down near the beginning. ASSUMING that this problem is being caused by this rubbing, I ask if anyone has had a similar experience, can tell me why the gap may be smaller toward the end of the record(manufacturer or installer error?),and what possible solutions(short of taking an exacto knife to the rubber pad on top of the lift or grinding a bit more of the curved area at the bottom of the arm away) might be possible. Have a friend with a near identical set up that was here listening today that will look at his gap tonight and report back. Have also sent an email to SME. Many thanks, LS
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Add a cartridge spacer may help https://www.ebay.com/itm/Delrin-Headshell-Cartridge-Spacers-non-magnetic-non-inductive-turntable-VTA... |
Actually, a cartridge spacer, if flat across the entire surface, will make the problem worse. The SME arm has this problem with tall cartridges or thick headshells. In order to open up space between the cue pad and the tonearm, you need to add a shim forward of the cartridge bolts and tip the cartridge down in front. Then lower the tonearm at the tower until the cartridge is level or obtains whatever VTA you were using. An Arche headshell enables this adjustment without a shim. Unfortunately it's expensive. |
As mentioned I seem to have stopped the serious mistracking by very slightly lifting the outer side of the assembly into a more level position. Seems odd that what was a well regarded arm has such inelegant ways of adjusting azimuth and VTA. I am somewhat lucky that mine has what I assume is an add on kit that includes a long VTA adjustment screw but even this requires you too loosen the entire assembly and then make a fine adjustment. Perhaps I will grow to master it but since loosening the assembly can possible affect the interaction of the bottom of the arm with the top of the lift, I may need an expert to show me just how little to loosen the screws to allow VTA adjustment without moving the entire assembly so much that the previous mistracking might return. My standard SME detachable head shell is not very thick and I do not think the Kiseki is very tall and from what I can observe lowering the tower may not increase the gap since I believe the entire assembly seems to be bolted together and moves as a single unit, could certainly be wrong or perhaps it is the tilting of the cartridge that might increase the gap, but from what I can tell nothing seems to allow you to independently move either of the two elements(since the lift is down as far as it can go) to increase the gap. My first listening post adjustment seems to indicate that the serious mistracking is gone. Now just have to have a cartridge whisperer come by and check on all the parameters since I made the base closer to level. Thanks again and please do share any data if I have failed to understand responses or my assembly. LS |
The best way to adjust azimuth with that arm is to acquire a removable headshell with built-in azimuth adjustment. Jelco offers a nice and inexpensive magnesium headshell with the feature. I think I have that same Chinese add-on VTA adjustment kit on my SME 3012R. It doesn't work well for on-the-fly adjustments, but is calibrated to allow repeatable changes to VTA. |