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In the Forum: Analog Playback
In the Thread: Ultimate Turntable
Post Subject: Back to the disc/platter interfacePosted by Paul S on: 3/27/2008
It appears that in most cases like the DaVinci, the gigantic platter is used only as rotational mass. And in most other cases where the manufacturer does speak of the platter as an impedance sink, either the platter material seems ill suited to the task or the disc is none-the-less poorly coupled to the platter.
I have recently seen two designs that attempt to seriously address the disc/platter interface without a vacuum holddown, namely the Townshend Rock V and the Walker. Both of these designs use an adjustable spacer at the spindle that is said to give purchase to a wide screw-down clamp that in turn is said to do a uniform job of coupling an avaerage disc to a platter that is designed to be a sink.
The Townshend eschews the vacuum because of the cost and because of ruumors of record damage caused by particle embedment caused by the vacuum's force. I have noticed no such damage in 20 years of using the (low pressure)vacuum, by the way, and I have never used the thin, soft mat Sota offers as a sop, either, since I prefer the sonic results when my records rest directly on the hard "interface" mat itself. Anyway, no "embedment" issues in my case.
The most interesting thoughts on "no vacuum", IMO, come from Lloyd Walker. He likens the sound/effect of the vacuum holddown to the sound/effect of driving along in a modern car with the window just slightly cracked open, where whatever "it" is "goes away" when you hit the button and the window closes tight. Walker insists that there is always noise from even the slightest leakage along the disc/platter/stylus interface, and he insists he eschews the vacuum because his system "sounds better".
Well, I have never seen a clamp that actually creates uniform pressure across a disc the way even a low pressure vacuum can do it. But I have not seen or tried Townshend's or Walker's systems, either. Townshend must be re-thinking his own system, however, since he has mentioned trying a rim weight to aid the center clamp. Again, the idea is more about the "impedance drain" than about just flattening the record, although that is a good idea, also, IMO.
Sad to say, neither of these otherwise-interesting TTs have provisions for multiple cartridges, although I suppose it would be possible to fit a multi-wand type arm onto the Townshend. I have to say I would really like to be able to easily use a mono cartridge and also I would like to have the option to play 10" discs and 78s, as well, and I can't do any of these things at present.
C'est la Vie.
Paul S
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