[net.audio] If I may step aside from the CD/LP Wars,...

rfg@hound.UUCP (R.GRANTGES) (06/07/85)

[]
If I may step aside from the CD/LP wars for a moment or so, I'd like to pass
on a couple of low cost gimmicks I have lately discovered that appear to have
a very high cost/effectiveness ratio. (That's the way you say it although it makes more sense as a high effectiveness/cost ratio)
I recently purchased from some mail-order (catalog) place - don't remember the name, but it was one of those expensive places whose catalogs come unbidden in
the mail if you get on the right/wrong lists - two gadgets that have amazed me
by apparently improving my enjoyment of my phonograph. Each was about $10 or $12plus shipping.
Ther first was a mat made of genuine carbon fibers that fits tightly over the
turntables center post. Assuming the turntable is grounded, the purpose is to
drain off static charges from the record. Now Years ago I saw an explanation
of why this wouldn't work. Unfortunately for me, I believed the explanation.
The truth is, it does work. Now I have tried a lot of things in the past,
and some worked sometimes. e.g., burning candles ionize the air - if you use
the right kind of candle. Beeswax works well, the usual petroleum derivative
candles don't. The "zerostat" gun to zap ions onto the record works for me
sometimes, but not usually and is too much of a pain to bother with most of
the time. This pad really works for me. There seems no trace of static
fields around the disc. dust blows off. I often don't even bother mopping
off the dust. The brush on the shure cartridge is sufficient. Gone are
all sorst of crackles and pops. 
Many of which I didn'r realize were static electricity caused.  THere is still
an occasional POP, or BANG, I don't know from what, but they repeat at te same point. This, of course works best on new teldec vinyl records, but Ive also played older garden variety records with about equal success. It <does> reduce
background noise.
Item is labelled "Omega One Sound Saver- Transcriber Co. Inc."

The next gem is a little, ivory colored plastic, three-legged record clamp.
It is marked "EON Canada Patent Pending." Eacj leg has a small rubber tip
which presses on the record. A central assembly slips over the turntable
center post, the three legs rest on the record. You press down on a plastic collar around the center-post collet. this puts downward pressure on the record
which is maintained by the collet's grip on the centerpost. After playing you
lift up on the collar and the collet pops off the spindle, releasing the
record.  It is my impression that this device is cleaning up the sound of my
records. The effect is subtle, but it seems to shift the reproduction from
disk in the direction of the "clarity" we have come to associate with CD's. 
I am not usually troubled with acoustic feedback - the margin of stability is
quite high, but it is reasonable to assume that long before a system will 
oscillate from acoustic feedback, the sound quality will be afflicted with
...muddy quality? I don't know. And I admit I could be mistaken, however
the difference seems big enough to me that I am now using this gadget
full time. It is a minor inconbvenience, but less so than trying to use the ZeroStat. It is extremely light, and is not going to affect my turntable
bearings one way or the other.
Good Luck, I recommend both gadgets highly.

-- 

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

ben@moncol.UUCP (Bennett Broder) (06/08/85)

No, the benefit of the record clamp is not imaginary, it is one of the
reasons that Oracle and Sota vacuum turntables sound so good.

There are 4 reasons that record clamps work:

--

1) Vinyl resonances

As the stylus accelerates laterally and vertically to follow the
groove undulations, forces are generated on the order of 1000 g.
All materials have inherent resonances that can be excited if enough
energy is applied to them, and vinyl is actually quite a "lively"
material in this sense.  Some of the brittle harshness heard in modern
music systems is actually a result of the stylus reading these
mechanical vinyl resonances, which have been excited by the stylus
itself.

2) Vinyl as an Energy Storage Medium

Vinyl is an elastic material (i.e. "springy")  This means that energy
that is fed into it is actually absorbed for a certain length of time
(like a spring compressing) and then released over a certain length of
time (like a spring expanding).  The drawbacks are as follows: as the
stylus plays a transient it generates a shock wave into the disc.  You
hear the transient and then you hear it echoing back as the vinyl
releases the stored shock wave over time.  The major audible effect is
a general blurring and smearing of musical detail, since this process
is going on throughout the entire duration of the playing record.

3) Vinyl as a Transmitter of Acoustic Energy

Acoustic energy in the air is reflected by or stored in the vinyl, and
is retransmitted back to the stylus as unwanted vibration.  Result:
further blurring of detail, usually accompanied by boominess in the
bass.

4) Warps

This is one we are all familiar with, and is again due to the
elasticity of vinyl.  Warps upset the stability of the entire playing
system, actually cause a change in the pitch of the music in the
groove that the warp deforms (warp wow) and in general create severe
subsonic problems throughout the entire reproduction chain.  A warp
also results in a portion of the record being suspended in free air,
which increases dramaticlly its susceptibility to all kinds of
excitation.

--

The above, excerpted from an Oracle white paper, is given in support
of their record coupling system, consisting of a special turntable
mat, a screw on record clamp, and a little spacer which raises the
record slightly in the label area.

I would highly recommend purchasing the Oracle Groove Isolator mat and
an appropriate record clamp.  The Oracle mat is completely flat
(sculpted ridges create air pockets under the record that resonate),
and made of a special damping plastic absorbs vibration before it can
be retransmitted to the stylus.  Try tapping the runout groove with a
pen and you will see what I mean.  On a normal mat the sound is a high
pitched 'tick', on a record clamped to the Oracle mat, a dull, barely
audible thud.  I think you will find that using a record clamp in
conjunction with this mat will yield improvements far more noticable
than using the clamp alone.

Ben Broder
..ihnp4!princeton!moncol!ben
..vax135!petsd!moncol!ben

dmmartindale@watcgl.UUCP (Dave Martindale) (06/10/85)

The Oracle clamp is particularly effective, I think, because of the spacer
under the centre of the record and the fact that the clamp exerts
pressure only in a circle at the outer edge of the label area.  When
it is screwed down, the record would be flexed in a manner that would
tend to apply pressure against the mat over most or all of the record
surface due to the vinyl's springiness.  

I haven't seen an aftermarket clamp that works in the same way.
Also, the Oracle depends on the turntable having a threaded spindle
to screw the clamp onto - could a clamp that just uses a chuck develop
as much force?

(When I was shopping for a new turntable last year, I considered an Oracle,
but eventually decided it was just too much money for me.)