Technics SL1200 plinth damping

[mulane]

I'm new to the world of DD turntables and I'm currently fitting a self-made aluminium armboard to my Mk2 techy and have had to take off the rubber base and the hard intermediate damping layer (IDL?) which I had to drill to make room for the armboard screws.

While the IDL was still on the deck I prodded it all over and was very surprised to find that it actually rattled in some spots against the aluminium top casting! The screws were all tight. It did not seem to be a very good application of "constrained layer damping" as I understand it. It also seems to be quite thin in many places-often just 3mm.

I've read on Audiogon that someone covered the aluminium top casting with plastic cling wrap and then applied a layer of liquid silicon on the IDL before screwing it back on. He stated that this seemed to bring about an improvement in sound.

Has anyone tried this? I would be intersted in a discussion about the Technics plinth and how effective it really is.

(yes I have seen Frogspits laminated DIY plinth and cannot wait to hear how it sounds.)

[mulane]

I thought, as I reattached the rubber base, that maybe the rubber squeezes the IDL tightly to the aluminium top, and that I had been too hasty, but when I tap the rubber base it still rattles in places, mmm...

Anyway, here are a couple of pics of the JH Formula IV (with glued-on Denon magnesium headshell and AT33PTG) on the deck.

[scoobs]

I did the very same thing with my old 1210, I bought a used one off ebay to play about with. I used silicone sealant, and also large amounts of arboseal compound (blacktac) and to be honest neither worked very well, the underside of the chassis is too contoured to allow for a proper coupling between the two layers, some areas have several mm of clearance and others have maybe 1mm or less clearance as you have alluded too. I think the only way to sucessfully do it would be to pipe a large amount of silicone between the two, compress them and trim the excess from the edges, but you are left with the problem of not enveloping the pcb for the start button, pop-up light and pitch slider etc. It is a challenging project and I gave up on it and bought a self contained motor unit tt.

[Mike]

It is a challenging project and I gave up on it and bought a self contained motor unit tt.

What would that be then?

[scoobs]

What would that be then?

oops, sorry for hijacking.

[Mike]

Looking veeerrrryyyy nice too!

[scoobs]

Cheers Mike. Have you had the 3000 back yet?

[Mike]

[Marco]

Bloody Vantage take forever to get their arse in gear - a bit like Expert Stylus

You've got far more patience with these things than I have, matey!

Marco.

P.S Scoobs, looking cool mate - verryyy cool

[Mike]

Bloody Vantage take forever to get their arse in gear - a bit like Expert Stylus

You've got far more patience with these things than I have, matey!

All will be well young grasshopper!

Some things are worth waiting for.