Envelope trigger circuit for guitar
keen at austin.ibm.com
Wed Mar 13 20:21:05 CET 1996
> Can anyone recommend and/or point me to a good source (circuits or
> methods) for making or designing a good, reliable, and easy to use
> guitar envelope trigger? I want to use my guitar to trigger an
> envelope generator that will drive a VCF and VCA for guitar effects.
> In the past, I've casually tried to cook up cheap and dirty triggers
> using an envelope follower and comparator but quickly found out that
> it's not a simple job. The input signal can vary so much that you
> constantly need to ride the comparator trigger level to get a reliable
> trigger. I was hoping to find a more adaptive trigger that would be
> "smart" about the trigger level.
Don Lancaster's "CMOS Cookbook" has a circuit for using a CMOS opamp
to ride the level of a photodiode to pick off sudden transients in
light level, for all the reasons you note. Take a look at it.
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