> This is a very good question. IMHO the value of an old Buchla or Moog
> is in the history of the instrument. After all, one can buy a modern
> modular synthesizer with much better audio characteristics (Signal to
> Noise ratio, CV rejection, etc.). :-) I would tend to favor replacement
> only when repair is necessary, and then with the closest modern
> equivalent. One can always clean up the noise later with outboard or
> computer processing. This way one can keep the historic accuracy of the
> instrument and still use it for recording.
I think perhaps I agree with you in principle but not in practice. :-)
It is true that much of the value of an older synth is its history, and
perhaps the goal of restoring a synth is to return it to factory-new
condition. But it is not necessarily true that one can buy a modern
equivalent with better audio characteristics. Yes, I put the word
"equivalent" into your mouth, but my point is that modern synths don't
always have the same features as older synths. So substituting a modern one
for a vintage model may or may not be a viable substitution, depending on
what you're after.
Your last two points are the ones that I find most difficult to ratify with
practice. First, I've spent a number of hours over the past several weeks
attempting to clean up noise in some location and voice-over recordings with
computer processing. I have some pretty good tools at my disposal and I
still wasn't able to achieve completely satisfactory results. The
long-standing studio advice about getting as good a signal in the first
place still stands, despite new-fangled noise-reduction techniques.
Second, it's not always the case that a historically accurate synthesizer
can actually be used for recording. I've attended recording sessions in
which some "vintage" synth was brought in for the occasion, and its
oscillator drift (or some other aspect) was so bad that it couldn't be used
for the session. Was this because the synth was old and uncalibrated? Not
always. We all know that one of the things we love about MOTM oscillators is
that they don't drift like older designs. I don't think many of us wax
nostalgic for VCOs that drift so badly that the instrument won't stay in
tune for the duration of a recording session, or less.
IMHO it comes down to the goal of the restoration: is the goal to return the
instrument to factory-new condition, i.e., a museum-style restoration? Or is
the goal to put the instrument into as "musically useful" a condition as
possible? I know that "musically useful" is a subjective term, which is why
I put it in quotation marks. Some people may find oscillator drift useful; I
personally do not. If the Buchla's performance (e.g., frequency stability,
noise level) can be improved by substituting new op-amps, personally, I'd do
that.
In short, I'd say it's up to Paul, based on what he intends to do with the
thing.
--Adam