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Subject: Re: [motm] (unknown)

From: Adam Schabtach <adam@...>
Date: 2003-11-29

> I think the confusion is we've been talking about 'recording' and I
> think you're talking about just 'playing' the thing through various
> recording equipment.

Yes. Generally I don't record anything from my MOTM until after I've played
with it for awhile. Once I've set up a patch and it's doing something that I
want to preserve, I record it. At that time there is very little danger of
accidentally sending a large signal into another device, because I'm no
longer moving patch cables around. The situation I'm talking about is before
that: when I am moving cables around, and hence the possibility exists of
accidentally plugging the output of an oscillator directly into whatever I'm
using for monitoring.

> Well if you are just running the "10v p-p whatever wave" from the VCO
> directly into the board (which you probably will NOT be doing - eh?)

Well, why not? Paul's oscillators sound awfully nice, no?

More seriously, though, yes, it's unlikely that I'd deliberately patch a VCO
directly into a mixer channel. However, it's entirely likely that I'd patch
a VCF into a mixer channel, and I might be feeding that VCF with a VCO, and
in some instances the gain of the filter could be close to unity, no? Or
what's the peak-to-peak output of the various MOTM filters when
self-oscillating? Off the top of my head I don't know.

That actually brings up a whole 'nuther point: is anybody using a DI box or
some other input buffer between their MOTM and their console when recording?

> So protect all your equipment by learning about "Gain Stages" and you
> will be a-ok.

I like to think that I already know at least something about gain stages,
having been fiddling with synths, mixers, and recording devices of various
media for over 20 years. My point is that there is a much larger range of
signal amplitudes present in a modular synthesizer than in any other piece
of equipment that's likely to be present in a studio. This is particularly
true if you start mixing modules from different sources. Someone loaned me a
non-MOTM module recently, and its output was so low that I was quite
convinced that it had been damaged in shipment. In order to get a listenable
signal out of it, I had to turn up the input trimmer on my mixer a good deal
more than I do with anything else in my studio. As it turned out, this was
considered normal for this module. Had I accidentally plugged a 10V p-p
signal into that mixer channel, I would have produced an uncomfortably loud
sound at the very least. Yes, of course I was careful to ∗not∗ plug a 10V
signal into that mixer channel, but accidents do occur...

However, as I think about the gain stages that were present in that
particular configuration, a lot of this discussion hinges on the details of
the equipment itself. Maybe a system is going to be able to pass a big
signal on to the power amp and speakers, which could be a problem; or maybe
it's not--maybe it will just saturate and pass along a not-very-big but
saturated signal, which might be ugly but probably won't be a problem.

In any case, I think we've been 'round in circles enough over this. I'll
continue to attempt to avoid problems by monitoring at low volume levels and
keeping at least two attenuation stages between my MOTM and my powered
monitors.

True story: I did once accidentally patch an unattenuated Serge oscillator
output into a pair of powered Genelecs, with nothing with less than unity
gain (and with plenty of headroom) in between. I jumped about eight rack
units, I think. :-)

--Adam