Albert Porters after market panzerholz plinths

Mapman, You are quite right that not all that torque is used during play. We like to think that some torque now and then is needed to maintain speed stability in the face of stylus drag, which can vary in degree related to the tortuosity of the record groove. Torque is also in play when the platter goes off speed for any other reason, like due to cogging, etc. I never saw anyone put any numbers on these forces, so I don't know how great or small they may be. If we ever had any real facts to go on, we would not need to have these rambling discussions.

Also my understanding of the panzerholz material used in Albert's plinths is that it is very rigid but lower mass than comparable standard wood materials, so I'm not sure that adds up either.

The Panzerholz used in Albert's plinth is very dense. It is made up of European red beech plies compressed under high pressure into a sheet about 1 1/4" thick. It's density is on the order of 85 lbs./cubic ft., which makes it heavier than than all but the densest exotic hardwoods.

John

i own 2 vintage tt's with Dobbin's plinths; a Garrard idler drive 301, and an Technics SP-10 Mk3 DD. i did also have a Dobbins plinth'd SP-10 Mk2.

so why do these plinths improve performance over the basic stock tt or OEM plinths?

my opinion, already touched on by others here, is that 60's, 70's and 80's 'even SOTA' tt's had their strengths and their 'areas of potential improvement'. obviously the strengths were that much more R&D could be directed to building motors since these companies were much more able to spend that money than the typical tt builder of today. OTOH their weaknesses were that the case work was an afterthought in comparison. system performace (cartridges, arms, phono stgaes) did not necessarily reveal limitations of the build quality back then.

it's not simply adding mass, or adding isolation. it's more a matter of engineering the precise plinth construction that will optimize the drive system. what is the best combination of materials put together in a particular way to allow the tt to have maximum livelyness, low noise, and drive which sounds the best.

i know that Steve Dobbins built many dozens of plinths before he sold his first plinth for the SP-10 Mk2. he did the same for the Garrard 301, and then again for the SP-10 Mk3. i know he experimented with many materials and ended up with a constrained layer design. eventually on the Mk3 he discovered that (in his opinion) mounting the Mk3 with the casework still in place compromised the performance due to the high torque of the Mk3 motor. the original casework allowed 'flex' and a slight smearing of the sound. eliminating the case and mounting the Mk3 'nude' inside the plinth performed better.

not every plinth designer necessarily agreed with Dobbins on that issue.

in any case; it should not be surprising that 30+ year old casework could be improved upon.

Dear Mikelavigne: We have to remember too that in the case of SP-10's or EMT these TT's were designed for Radio Stations/broadcasting more than to home audio systems.

Nice to hear that I'm not totally wrong about my thoughts on a nude ( non casework. ) SP-10 as a improvement.

regards and enjoy the music,
Raul.

Raul,

to be clear; my comment on the nude (original case-work removed) SP-10 Mk3 referred only in the context of installing the nude SP-10 Mk3 inside a custom plinth.

possibly that was inferred by your comment;

Nice to hear that I'm not totally wrong about my thoughts on a nude ( non casework. ) SP-10 as a improvement.

but that was unclear.

you could be referring to a nude SP-10 with no plinth. in that case, although i have not listened that way myself, i would be skeptical it would be optimal.