Synth-drum CV

[Andrew Schrock]

On Wed, 3 Jun 1998, Andrew Puls Q-Bot Eye wrote:
> I am putting the plans together to build a percussion synthesizer.  I
> was wondering if I could use the same control voltage (percussive
> envelope generator) to control both the VCA and VCO or VCA and VCF or
> any combination of the three. Keep in mind that because this is a
> percussion synth the controls do not have to be as precise or complex
> as a regular synth,  this is why I am asking.  I realize that if this
> IS possible, the decay rates on all three (or two, or whatever) will
> be the same. I just wondered if this is possible,  or do I HAVE to
> build a seperate envelope generator for each of these devices?

Nah, you probably don't. I routinely run 1 ADSR stacked with bananna plugs
through both the VCA and VCF. Of course, *some* voltage loss is to be
expected, but frankly I've never had enough cause to waste another
envelope generator on it. The modular I'm discussing here is an ASM-1
which I usually run my midwest analog products drum machines through 
triggered by my paia fatman via midi. Just FYI. This setup makes a nice,
weird, squawky sound. (although the VCF on the ASM-1 doesn't respond to
being overdriven as well as I had hoped) Really strange things tend to
happen when I put the decay really long on the ADV-bass, sounds extremely
rubbery... the sound directly from the MAP boxes is nice, but not as
uhmmm... weird/gruff as I would like (altho IMO *so* much better than an
roland x0x drum box... <stifles a jaded yawn>). I routinely route
percussion through my modular to toughen up the tone a bit. I also sample
it so there's no need to be able to recreate some of the stuff. Some of
these sounds have turned out to be my handiest drum&bass samples! 

Hurm.. after I typed that I realized running the same ADSR through the VCO
as well might tax it a bit too much, especially if you want a full VCO
sweep. (for stuff like bass drums you might not even notice) And then
there's the question of if you would want the filter to have a different
envelope than the VCO. If you're really short on parts/time/effort you can
probably _get_away_with_ just 1 ADSR, but it certainly would be nice to
have 2. Hey, you could even just slip a simple AD generator in there from
a single opamp, that's not too hard, right? 

I'll probably run home today and play with my setup some more.. I haven't
had the time recently to get truely nifty percussive patches going. 

On a totally different note, I wonder if I'm still the youngest member on
the mailing list.. I bet I was when I joined a few years ago but I don't
know any more... I guess when I turn 20 in November I'll just be another
old fart, right? heh.. 

Andrew