Clamp or weight for Technics Direct Drive?


I'm experimenting these days with a Technics SP-15 on the nice heavy Technics SH-15B2 plinth. Right now I'm running a Denon 103R in an Audio-Technica ATP-12T, and so far I like what I hear.

I'm wondering about using something to stabilize the records. I've generally used a clamp in the past, but the SP-15 has a very short spindle, and the collet on my Michell clamp doesn't reach down far enough to grab it. Is there an inexpensive clamp that would work? I could put a thinner mat on the platter, but the Technics OEM rubber mat is nice and does a great job of damping the alloy platter.

Would a record weight be preferable to a clamp? Seems like the Technics has at least some similarities to the heavier non-suspended tables that use a weight. Just not sure if the bearing in the SP-15 is stout enough to take the extra pressure.

If anyone is using a clamp or weight with their SP-10, 15, 25 or SL1200, I'd love to hear about your experience.

David
armstrod
Ekobesky,

I considered the KAB rubber grip for a prior turntable, but I haven't had the best of luck with clamps that use friction fit rather than a mechanical collet. They seem to lose their grip over time, and then won't stay down on any record with a serious dish which, of course, are the ones that need clamping the most. Do you have experience with the KAB product that the grip stays tight? I'll also email Kevin at KAB and see what he thinks.

Thanks for the reminder that this may be a good solution.

David
A friend of mine machined a stainless weight for my SP25. I had used the 25 for a few months prior without any clamp or weight. Since getting the weight, I haven't played an lp without it. It brings the sound into focus and is very noticeable. The motors in the Technics SPs seem to be robust enough that I haven't had any problems mechanically at all, and I trust the bearing is doing fine also. I also use the ATP-12T arm and it seems quite good.
My JA Michel record clamp wore out yesterday morning. I had been looking at the HRS clamp but it looks way too heavy for a 1200.

Fortunately I found this NOS clamp this morning:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=012&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=220105797204&rd=1&rd=1

Looks like it was designed with DD decks in mind.

***
Psychicanimal,

Taunting me with your one-off eBay find? :-)

Actually, that's exactly what I'm looking for, but your vendor doesn't appear to be offering any more and a search reveals no sign of the OEM.

The HRS clamp is interesting; it weighs about 10 oz. Do you think this is more weight than a Technics bearing can take? That's one of my questions. Also, the HRS is $195, pretty spendy for this application.

I've also found that there is a Rega version of the Michell clamp, specifically made for the short spindle Regas. Is this the version you were using on your 1200? How well did it work?

David
I use a Michell clamp on my SP-10 MK II which has a thick mat. There is plenty of grip. Perhaps I have a longer spindle. It fits plenty tight.
David

I use a heavy Audiolife sub-platter on my SP-10 Mk2 with a heavy brass record clamp. I have also used an AT-666 sub platter as well but the 5Kg Audioplatter fits and gives the SP-10 better grip and micro-dynamics to the point where I can say the performance is comparable to my Micro-Seki RX5000 - comparable, not necessarily the same. The torque on the SP-10 is so great that the start up time is still fast. I don't think there will be any issue with the bearing as the extra weight will not stress the lateral forces.
Okay, so I think I should try a weight - seems like that will be a good match for the SP-15. Can anyone recommend a decent inexpensive one? Turntable Toys on eBay has 2 or 3 different models with slightly different weights, sizes, materials and prices. Has anybody used any of them? Where did you buy the one you have? I'm guessing the critical factors are whether the bottom is milled flat and the spindle hole is dead center. I'm not really concerned about cosmetics. It can be a maximum of about 1.5" high.

David
Psychicanimal,

I've done just that. I also wrote Kevin at KAB and he said he thought the Record Grip would work, but that a weight might be even better.

Was the Michell clamp you were using the Rega model for short spindles?
You could get one machined pretty cheaply. I have an audio friend who is a machinist and he made me one very similar to this one. Said it took about 20 minutes.

http://www.soundfountain.com/amb/puck.html
The SP-15 and SP-25 are virtually identical tables mechanically, differing mainly in their electronic control and speed precision (and of course the 78RPM capability of the SP-15). Both tables have a very high-torque motor, and their bearing is of high quality, and very durable. I use the superb clamp available from Pro-Ject (Sumiko in the USA); it is VERY heavy, and doesn't "phase" the start-up time or rotational accuracy of my SP-25 at all. You may, if you want, desire to have the brake potentiometer re-calibrated to obtain the same stop-time, now that you have the extra weight of the clamp to deal with. Furthermore, it's not really a clamp, but rather just a heavy weight, as it does not clamp onto the spindle at all; it just sits on it. It is therefore extremely practical, easy and a pleasure to use on these tables (and for those lucky SP-10 owners as well). You should have no worry whatsoever about whether your SP-15/25 is durable enough for a heavy clamp. I have obtained superb results from it.

I hope this helps.