Phasers - if you don't have enough already

[Don Tillman]

   From: "jhaible" <jhaible at metronet.de>
   Date: Sun, 30 Aug 1998 10:54:21 +0200

   >    But what if we want to replace the opamps with 4069's, too? 
   > 
   > Note that 4069 FETs are noisey when used as linear amplifiers.
   > (When they're voltage controlled resistors it's not a problem.)  

   Good point.
   It was not that much an issue in the Wasp Filter - it *is* as little
   noisy, but not that bad. But I can see that it could be worse with
   the phaser, because of the limited voltage across the FETs that
   work as resistors. What was maximum voltage for decent
   distortion ? 

Guitar levels, about a volt or so. (Depending on your tolerance for
distortion of course.) 

   And did you feed part of the audio signal to the gate to linearize
   the FETs, or was it a strictly low number of components device ?

I should have fed 1/2 the audio signal into the gates to linearize the
FETs, but I didn't know about that then.  Hey, I was only about 17
years old at the time!

Hmmm, I don't think any of the other FET-based phase shifters
linearized their FETs either.  The MXR Phase 90 certainly didn't.

  -- Don