Arm board

[T-bone Sanchez]

Okay, Ive got a thorens 160 with which I'll use a sme 3009 s2. So far Ive made the top plate out of 2.5mm carbon fibre and now need to make the base. My question is how critical is the base to the sound? I wouldnt want to compromise the quality of the carbon fibre with something like mdf, however if it makes no difference I'll use what I can find timber wise. Originally I was going to use 10mm polycarb or similar but Im struggling to find a small off-cut.

Ta

[zanash]

Your right it will play an integral part in the sound of the player.

I had a 160 super many years ago.....and used MDF, plastic, perspex.

The MDF was actuall a lot better than the stock plastic thing the TT came with at the time. Plastic sheet ....sort of chopping board material not impressed but the perspex one was very good and the last one I made. It was easy to drill and cut and looked good when finished ....it was a square block cut to accept a helius standard arm.

If you can build up layers of the carbon fibre sheet "plywood effect" that ought to do the trick.

[T-bone Sanchez]

originally I thought about layering carbon fibre but the stuff aint cheap, its still an option though. Perspex was my next thought but like I said Im having trouble finding some. Do you think the harder the material the better?

[penance]

http://thefrazerco.com/

^ i got some acrylic from these people, quick and easy service and well priced.

[zanash]

It 15 years since I messed with 160 so can remember the exact route I took....but you need a good energy transfere between arm and sub chassis.......

how about bolts three bolts upright tighten the nut to the subchassis and loc with loctite add two more nuts use the lower to lock the upper fit arm board and another nut loctite in place....job done!

[7_V]

Corian acrylic is a good material - inert and dense. Your local kitchen fitting workshop may have some off-cuts.

Baltic Birch Ply is the wood I would move to from MDF for my speakers (if my new range used wood, which it doesn't).

You can also use 'dedsheet' or similar to dampen the material.

[T-bone Sanchez]

Acrylic seems to be the way to go. I'll look around for some but for now Im going to use some dense upvc board, its 10mm thick and is very easy to work with.

I take it that the idea is to stop the vibrations the sub chassis is picking up transmitting back through the arm?

[zanash]

No....it's to make the arm and sub chassis one unit ...so what affects one will effect the other ....but then there are other schools of thought.

[T-bone Sanchez]

So ideally we dont want any damping qualities at all in the arm board?

[7_V]

There's an interesting project based on the TD160/SME by Edgar Audio. Have you seen it yet?

Artex Turntable (http://members.home.nl/edgar.beers/artex.htm)

The Analog Department (http://www.theanalogdept.com/index.html) is also an essential port of call. They have a section specifically on the TD160.

Have fun.

[T-bone Sanchez]

Ive spent many an hour in the analogue department site but Ive not seen the other. I dont think your going to recognise this TT when its finished Steve.

[zanash]

Hum.....most arms bolt metal to metal on the top decks so I suppose that one avenue is no damping where as the regas are all damping [arm clamped to plinth].Its one of those suck it and see moments see which you preffer the sound of.