on 4/4/07 9:52 PM US/Central, Eric Jacobs at [log in to unmask]
> Modern phono preamps with adjustable EQ: Everything I use and
> have tested is sonically challenged, or inaccurate, or lacks
> flexibility, or is very clumsy to use (ie. DIY plug-ins which
> require you to open the case up and fiddle with inserting Rs
> and Cs into the motherboard).
This was recognized by Stanley Lipshitz in his AES paper "On RIAA
Equalization Networks," 1978. It's in Disk Recording, Vol. 1
He writes in part -
Most current disk preamplifiers, including some very expensive models, have
audibly inaccurate RIAA equalization. This severely limits any conclusions
that can be drawn from A/B testing of such preamplifiers. These errors are
due in part to the perpetuation in print of incorrect formulas for the
design of RIAA equalization networks commonly employed....
> How many of you use your mono/stereo switch on your phono preamp
> when doing transfer or remastering work?
The answer to this question, as well as most of your others, depends (in my
case) on whether the purpose is a preservation transfer, or restoration for
current, commercial release.
Unlike tape, virtually all of my disk work is for current release, so I
simply use everything at my disposal to improve the audio for current use.
This is what my clients expect.
Typically, for mono program material the phono preamp output is stereo, with
de-clicking, phase correction, auto balancing and possibly more light
de-clicking, summing to mono, eq, etc., all cascaded and performed at the
same time. I use analog eq presets on a phono preamp for my own initial
reference, but never slavishly, and sometimes not at all.
I agree with Steve Smolian (and George Martin) - use your ears.
We all have our prejudices. I personally don't care for tube designs, since
they drift over time, are slightly microphonic, etc. Likewise, I don't like
(analog) graphic equalizers. Some clients love them because they can
interact with them more intuitively, but they are relatively noisy and are
not repeatable. I think they are best left to sound reinforcement.
At first, the engineer wants to acquire the best equipment, but gradually
the equipment will seem to own the engineer. Eventually the engineer becomes
Audio Restoration + CD Mastering