Technics SP-10 Tonearm Pod instead of Plinth/Base


Trawling through the Audiogon forums for information on a suitable Plinth for a Technics SP-10, I came across a post by Raul.
Instead of putting the SP-10 in a plinth, he just put the TT on three feet and then had constructed a separate base that only housed the tonearm. (I haven't seen a pic of this BTW)
Following on from Raul's 'Thinking outside the square' approach, I thought I might be able to buy, or have made, a stand-alone 'pod' or rectangular tonearm plinth that could sit along side the SP-10. Has anyone seen something like this that I could buy 'off-the-shelf'?
The advantage of this is that the tonearm is decoupled from the TT and therefore distanced from any vibrations generated by the TT.
A down side is getting the right geometry for the tonearm in relation to the distance from the spindle; and then keeping the pod in the right spot.
If this is all too hard, I might still go with a plinth. I notice an E-Bay seller in Taiwan is offering a Teak plinth cut for the SP-10. Anyone bought one of those?
All comments welcomed!
dsa
Hi Weisselk,
Well, your comments are borne from experience that I do not have- they are very welcomed- thanks. Did you ever try cement or a conglomerate for a plinth? It's heavy. It's cheap. But, would it be any good?
Lewm- I had good laugh at the "Fehhh" in your comment. I had to say it out aloud to get it. Fantastic, I had always wondered how that was written!
I suspected as much regarding the use of perspex. I think you are also being kind in regard to it's use with belt drive- still a bad idea methinks. It does, however, LOOK good....
Does anyone have a link for the dimensions of the SP-10 showing the unit graphically and the same for a suitable plinth?
Another challenge is the use of an arm with limited or non-existent VTA. I imagine that I would have to use a small block mounted on the plinth to bring the arm to the correct height.
Another person suggested that "a 12" tonearm is best because of the SP-10's large platter". Does anyone know what this means?
Dsa,
You can get an exact 1:1 template for the SP10 chassis cut-out from Soundfountain. It even shows exactly where to put the screw holes. It costs only a few bucks.

What that person may have meant re the 12-inch tonearm is that the square shape of the SP10 chassis makes mounting of many 9-inch arms awkward at best, if not impossible in some cases, because you cannot attain the needed pivot to spindle distance without some real gymnastics. Mounting a 12-incher would be much easier, OR you can consider removing the motor from the chassis. For one example, I really could not properly mount my Triplanar next to my SP10, can't get it close enough because of the way that the Triplanar pivot point is offset to the outside with respect to its mount and because of the square shape of the SP10. Admittedly, this is an extreme case.
Dear Weisselk: +++++ " This is yet another of those "to each his own" audio discussions " +++++

No, it is not absurd or " bad idea " ( it is only a different " road " and you don't have to like it. ) to run the Sp-10 with out plinth if you have the right " tools " ( including know-how ) to do it.

Certainly your bad experiences about means you don't have those right tools.

Anyway, if what function to you is a different " road " good for you this is the important issue: that you be satisfied.

Like Jsadurni I'm satisfied using no plinth.

Regards and enjoy the music,
Raul.
Dsa, I think there may be some confusion over the meaning of "pod" in this discussion, but I'll come back to that.

A couple of years ago when I got an SP-10 Mk2A, I started researching plinth design. Initially I cut out a 20" X 18" sheet of 3/4" particle board (not even MDF) so I could mount an arm to enjoy the table while designing and building a proper plinth. I experimented with different mountings, from the Technics bottom pan directly on a shelf to various absorptive materials either under the pan or supporting the particle board frame. I have not liked any springy support and the differences between stiffer support and no support are minimal. But unlike Lew I've not had any problem with the table moving from start-up torque.

Researching plinth design was initially disappointing since there is little info on SP-10s compared to all the rim-drive sites for their Garrards, Thorens, Lencos, etc. One good source for information is the DirectDrive site (see review of plinth materials) but I can't access them now to provide a link. Another is Soundfountain which has already been mentioned. Many great ideas are available from Albert Porter, even if you choose not to buy one of his plinths. I'm sure the OMA slate plinths are excellent but they are costly (at least for my retiree budget).

One other thought for plinth material comes from Townsand Audio, make a mold of the proper plinth and use plaster of paris, possibly including lead shot. Still messy but easier than concrete.

Since I had met Raul and had several discussions with him, I ask for his opinion. Here is where I think there may be some misunderstanding. When Raul says he favors a non-plinth design, my understanding is that he is saying it is not a standard box frame or solid wood plinth. Rather it is similar to what I'm using except even smaller in dimension - just enough wood attached to the platter base to mount the tone arm. Then he places his AT suspension feet underneath the bottom pan of the motor unit.

Many commercial turntables include what is called an arm pod but they are attached to the base mounting the platter/spindle housing in some fashion. I believe this is what Lew is addressing when he talks about the mechanical integrity of the platter/arm mounting. Very few offer an isolated pod for the arm which could simply be picked up by itself because of the lack of a mechanical connection, other than weight. While I'm not an engineer, much of my reading discussed the importance of stability between platter mounting and arm mounting. Given the microscopic undulations of the record groove, the need for such stability makes sense to me if we want to insure the only vibrations picked up come from the stylus in the groove. And even with a very massive separate pod to stabilize the arm, imagine moving it for the small increments required for proper alignment overhang and offset!

Anyway, for a long list of reasons, my proper plinth has not been built yet, but I must say my SP-10 sounds pretty good bolted up to the single 3/4" board.
Pryso, You got the same idea I had re Raul's non-plinth. When I described it here pretty much as you did, Raul posted that I was incorrect, that his tonearm IS on a discrete outboard mount of its own. While Raul is not alone in preferring that type of set-up, it does go against the prevailing philosophy that there needs to be some rigid physical connection between bearing and tonearm. I personally am not going to say that Raul's SP10 can't sound good. I have just made my own decisions in the other direction, in favor of mounting any tonearm in or on the same physical structure that houses the turntable mechanism. The analogy that is vivid for me is that of a race car driver who gets in an accident with or without his safety harness buckled up. The link between bearing and tonearm assures that both elements of the playback system remain coupled during those rough moments.