Keyboard circuit (was Stretch tuning a resistor string)

[terry michaels]

Message text written by Harry Bissell
> On a related note, someone mentioned never having seen a temperature
> compensated constant current source in a commercial synth keyboard. <

A temperature stable constant current source can be made with an op amp and
3 resistors, such a circuit was used in  the Moog 952 keyboard.  

Terry Michaels