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From: kimr@tektronix.UUCP (Kim Rochat)
Newsgroups: net.audio
Subject: Re: VTA adjustments of Cartridges
Message-ID: <5208@tektronix.UUCP>
Date: Mon, 18-Mar-85 15:27:52 EST
Article-I.D.: tektroni.5208
Posted: Mon Mar 18 15:27:52 1985
Date-Received: Wed, 20-Mar-85 01:56:48 EST
References: <705@voder.UUCP>
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Organization: Tektronix, Beaverton OR
Lines: 68

First, for the entertainment of the audience, there are a large number of
cartridges that have vertical tracking angles that are impossibly too large -
The Sonus line springs to mind - VTA with the top of the body parallel to
the record has been measured at 35 degrees, and the back of the cartridge
hits the record before you're anywhere close to the right VTA.  However your
Audioquest 404 doesn't suffer from this problem.

Second, the shape of the stylus affects the sensitivity of the VTA adjustment.
Spherical stylii are impervious, elliptical more sensitive, and line contact
(Shibata, Micro-Ridge, Van Den Hul) being the most sensitive, proportional to
the length of their contact line.

You should first make certain that the cartridge is properly aligned in
all other parameters, using an alignment gauge.
There are 2 methods I use to adjust VTA.

1) Treble brightness/tone.  You ought to be able to hear this with a
   JC Penny's special.  When the VTA is low, the lower midrange is pronounced
   and muddy, and the treble is depressed.  When the VTA is high (usually the 
   case), the treble is zippy, zingy, and harsh.  Violins sound steely instead 
   of organic. Cymbals sound harsh and painful (at loud levels) instead of 
   having a pleasant "ding".  It's best to start with the back of the arm
   as low as it will go, and raise it in small increments until the treble
   becomes alive, but not harsh.  Try a piano recording, and adjust it
   up until you can hear life-like hammer strikes (they'll be absent with
   a low VTA), or use a violin recording and adjust up until you're aware of
   the "bite" of the bow, which is also absent at low VTA.  Female vocals
   are also particularly good.  The sibilants (f, s sounds) should be 
   clearly audible, but not hissy or SSSSSSSSy.  VTA too low makes them 
   inaudible, and too high makes them spitty.


2) Soundstage.  This effect is more subtle, and requires the use of stereo
   miked recordings.  When the VTA is too low, there will be a hole in the
   middle of the soundstage.  When too high, the sounds will be squashed
   together in the middle.  Wilson Audio recordings actually have written
   descriptions of what the proper soundstage was like, and what it will 
   sound like if the VTA is off.  It's best to try this on a stereo-miked
   piano recording, and adjust until the piano assumes normal proportions
   (e.g. not squished up or stretched out with respect to its apparent 
   height.

Since the proper VTA for each record is different, you'll have to be aware
of the general class of effects adjusting the VTA has, and listen critically
to each record to analyze the sound for characteristics that might indicate
an incorrect VTA.  Some recordings (like organ) lack the obvious indicators
and are therefore more difficult to set VTA on.

I do adjust VTA for each record I play, and pencil the setting from my
calibrated arm onto the liner of each record.  My arm has a 7mm total height
adjustment, which is not quite adequate to cover the full variation of records.
Note that this allows for about 2 degrees of VTA adjustment in my 242mm arm.

For my previous cartridge with a Shibata stylus, I adjusted arm height in 
increments of 0.25mm (changing the VTA about 4 minutes).  My current
cartridge has a Micro-Ridge stylus, and I have to adjust it in increments
of 0.125mm, for a 2 minute VTA change.  The difference of this small a change
is clearly audible on a good quality recording when you're changing between
"right on" and slightly too high or two low.  If you're way off to start, it
won't make much difference.  You can do a "binary search" (if your arm height
is calibrated) to converge on the proper VTA.

I know this all sounds like a lot of fooling around, and it is.  But the
rewards are worth it.

Good listening,
Kim Rochat
tektronix!kimr