Keyboard circuit (was Stretch tuning a resistor string)

[Don Tillman]

   From: "Tim Daugard" <daugard at sprintmail.com>
   Date: Tue, 18 Jan 2000 14:40:20 -0600

   Some one said use a voltage regulator for the keyboard resistor
   string. 

Who said that? 

   There are some benefits to useing a regulated current source
   instead of a regulated voltage source

I'll say!  The major benefit is when the player hits more than one
note.  With a current source the output is the lowest or highest
of the notes played.  With a voltage source you'll average in some
unmusical way unless each of the key switches is double-throw.

The only synth I know of that feeds the keyboard resistor string with
a regulated voltage is the Moog Taurus I.  And that uses double throw
keyboard switches.

  -- Don