Envelope trigger circuit for guitar

[gstopp at fibermux.com]

     A good reliable trigger extractor would certainly need a lot of 
     "smarts" for a signal like a guitar - you got the right approach IMHO 
     in thinking that the comparator threshold needs to ride the input.
     
     A long time ago in my crazy mad-scientist blow-up-the-house teenage 
     years I made a guitar trigger circuit that worked every time, 
     guaranteed, no mistakes, no errors, no delays, always a trigger every 
     time you wanted one, no question about it.
     
     You're gonna laugh. Okay, it's kinda goofey, it may offend some, but 
     imagine that it will be the listener at the other end of the recording 
     process who will be impressed by your fluent guitar triggering style, 
     okay?
     
     Here it is: make a metal guitar pick, solder a long flexible wire to 
     it, make sure your strings are grounded to the guitar cord shield, and 
     build a trigger-when-grounded detector. Hit the strings (or bridge) 
     with the pick whenever you want a trigger. The material used to 
     fabricate the pick itself should be chosen by the user for the 
     appropriate flexibility, depending on your preference as a player. 
     Since I'm not a guitar player I can't be of much help here. I don't 
     even know if this will damage the strings....anyway there's my silly 
     idea.
     
     - Gene
     gstopp at fibermux.com


______________________________ Reply Separator _________________________________
Subject: Envelope trigger circuit for guitar
Author:  johns at oei.com at ccrelayout
Date:    3/11/96 5:57 PM


     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.
     
     Thanks.
     
     John Speth - johns at oei.com