[net.audio] Turntable mats and clamps

prk@charm.UUCP (Paul Kolodner) (07/12/85)

Today I had some fun by calling the local hifi stores and asking about
turntable clamps and mats.  The original problem was that, after
having read on this net about this subject, I ran out and bought
a record clamp.  The trouble is that, since I have a manual turntable,
the cartridge can bump into the clamp at the end of the record, unless
I jump up, run across the room, lift the cover, and hit the cuing.
So I called to ask about a low-profile record clamp that would avoid this.
Well, the salesman told me that clamps and damps are out.  Today's 
high-end turntables are made of NON-DAMPING materials, like acrylic.
What say you all to that, eh??  He went on to explain that acrylic has
the same resonant frequency as a record, a statement which shows an
admirable ignorance of simple physics.  Damping takes out the harshness,
but music is sometimes harsh, blah, blah, and the logic started to
fade a little.
So waddaya say, folks?  Do we use rubber mats and C-clamps like
we used to, or do we go to glass?  
By the way, who knows of a record clamp with a low profile and which will
not bump into my tonearm?

rfg@hound.UUCP (R.GRANTGES) (07/12/85)

[]
I don't think it's fair for you to sic the whole net.audio pack of hounds
on your local hi-fi store guru, just because he's an idiot.  From your
article, at least he's an articulate idiot.  Why don't you give him an
opportunity to write to us all with his story in his own words.  Then
we can dismember him in a more fair and gentlemanly style.

-- 

"It's the thought, if any, that counts!"  Dick Grantges  hound!rfg

herbie@watdcsu.UUCP (Herb Chong [DCS]) (07/13/85)

In article <690@charm.UUCP> prk@charm.UUCP (Paul Kolodner) writes:
>Well, the salesman told me that clamps and damps are out.  Today's 
>high-end turntables are made of NON-DAMPING materials, like acrylic.
>What say you all to that, eh??  He went on to explain that acrylic has
>the same resonant frequency as a record, a statement which shows an
>admirable ignorance of simple physics.  Damping takes out the harshness,
>but music is sometimes harsh, blah, blah, and the logic started to
>fade a little.
>So waddaya say, folks?  Do we use rubber mats and C-clamps like
>we used to, or do we go to glass?  
>By the way, who knows of a record clamp with a low profile and which will
>not bump into my tonearm?

the salesman doesn't really know what he's talking about, if your
praphrasing is reasonably accurate.  i have used both kinds, as well as
glass, ceramic, and fibrous mats.  i'll stay with my conductive rubber
Angstrom and clamp.  you can try a Nagaoka rubber record clamp, but i
am of the opinion that unless the platter mat is of the right rubber,
you will not be getting all your money's worth.  the mission mat,
sorbomat, platter matter, or any of those type of mats are best, and
should be used with a clamp.  the key is very high damping in the mat
with tight coupling to the mat by a clamp.  if nothing else, your warp
problems will be reduced, reducing warp induced flutter.

Herb Chong...

I'm user-friendly -- I don't byte, I nybble....

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crandell@ut-sally.UUCP (Jim Crandell) (07/17/85)

> Well, the salesman told me that clamps and damps are out.  Today's 
> high-end turntables are made of NON-DAMPING materials, like acrylic.
> What say you all to that, eh??  He went on to explain that acrylic has
> the same resonant frequency as a record, a statement which shows an
> admirable ignorance of simple physics.  Damping takes out the harshness,
> but music is sometimes harsh, blah, blah, and the logic started to
> fade a little.

The salesman is obviously being honest with you.  Otherwise, he'd tell
you that a heavy damping material was what you need.  Of course, if it
takes out the harshness, since music is sometimes harsh, then
naturally you need a new moving-coil to put it back in.  Unfortunately,
he's actually a little behind the times.  The most recent research has
conclusively demonstrated that the best platter-mat material is a
foot-diameter sheet of diamond.  You see, the diamond has the same
resonant frequency as the stylus, and ....
-- 

    Jim Crandell, C. S. Dept., The University of Texas at Austin
               {ihnp4,seismo,ctvax}!ut-sally!crandell

wmartin@brl-tgr.ARPA (Will Martin ) (07/17/85)

Re: flat clamp wanted:

The old Radio Shack $5 (and overpriced at that) clamp (which I think
was/is the same as one of the English tweek company's models OEM'd to
R-S) has a low, flat profile, and comes out to just about the edge of
the label. In cross-section, it is:

                     --------
                     |      |
                     |      |
     ___------------------------------------___
  ------------------------------------------------

or suchlike. Mine grips my Linn-Sondek's spindle with tenacity (the
center hub screws on a split collet that clamps the spindle -- I guess
most use a method like that).

There is a glued-on turntable-speed strobe-marked paper ring on the top
that came unglued on mine; I never bothered to reglue it.

I use it or a little Denon weight (when I'm too lazy to bother with the
clamp) on a Marcof Glasmat. Sounds OK to me...

Will

mike@smu (07/25/85)

Audioquest makes a "low-profile" (how low do you go) clamp,
lightweight (plastic) so it won't disturb your suspension.  They've
got 'em at Omni Sound (Dallas, 931-6664). They are certainly not
as good as, say, a low-pressure vacuum, but they probably do some 
good...       M.H.P.

mike@smu (07/25/85)

Also, SOTA offers an acrylic mat designed to go with a clamp, so at
least that manufacturer doesn't find acrylic mats to make clamps 
obsolete...    M.H.P.