While we're talkin' about SSM VCA's...

[gstopp at fibermux.com]

     I guess what I'm trying to do is come up with some discrete designs 
     for all types of synthesizer modules to get around the chip 
     availability problems. Also building discrete circuits gives total 
     control of all parameters, like pulse width modulation thresholds and 
     envelope times and low/high frequency ranges etc. You can bring out 
     all the guts for input and output, and whether or not these get used 
     is the option of the builder. And always the goal is to make them with 
     parts that anybody can get, not just industry engineers who play golf 
     with distributor reps every week.
     
     Chips, whether they are available or not, are really intended for mass 
     production. You can see that AD chips are geared for console 
     manufacturers, for example. Some of them have specifications that are 
     so good that it's hard to justify building a discrete version, like 
     the AD multipliers or the SSM precision parts, but they cost a lot of 
     money and you have to special-order them.
     
     Some DIY gear is a one-time deal, for personal benefit. I can safely 
     say that I'll never build another Frequency Shifter now that I have 
     one, and it's got four AD532's in it (which are considered obsolete by 
     AD, BTW). But how will we ever not need another VCO? Or VCF, or 
     envelope generator? These modules are the bread and butter of analog 
     enthusiasts, and even when one enthusiast gets his fill and calls it 
     quits, another young one sprouts up with a fresh demand.
     
     - Gene
     gstopp at fibermux.com
     


______________________________ Reply Separator _________________________________
Subject: While we're talkin' about SSM VCA's...
Author:  Christopher List <Christopher_List at sonymusic.com> at ccrelayout
Date:    4/12/96 4:47 PM
     
ps.
Gene, are you staying away from the in-production SSM chips as well? - For fear 
that they might be discontinued? BTW, thanks for the VCF posts....