wasp (was: Re: [sdiy] Comparator = Opamp ??)

[Don Tillman]

   From: WeAreAs1 at aol.com
   Date: Wed, 7 Mar 2001 22:25:15 EST

   The FET-attenuator-driven-by-envelope-follower thing is used in
   quite a few FX circuits, such as the Maestro Ring Modulator and the
   original BOSS CE-1 Chorus.  It gets the noise reduction job done,
   but tends to mess up the decay of low-level signals.  Also, when
   the gate is open, the background noise is usually very audible,
   especially with lower level signals.  Companders tend to behave in
   a less obtrusive, more musical fashion. 

Companders can also be a musical disaster.  My favorite worst case
scenario was a DBX cassette recording I made of myself playing guitar.
This was a completely mellow jazz guitar sound, think Pat Metheny or
Wes Montgomery but with a lot less talent.  A deep bass sound with
almost no highs, so you wouldn't think it could possibly cause any
electrical problems.

But the playback was unrecognizable.  The companding DBX noise
reduction added a loud "chiff" to the transient of every note.  And
since there were no highs in original transients, the chiff was extra
inappropriate.

I hear a similiar effect playing a Wurlitzer piano through a BBD
chorus. 

  -- Don

-- 
Don Tillman
Palo Alto, California, USA
don at till.com
http://www.till.com