Back in the 70's, I did some work on a Mini-Moog (Model D) for a music conservatory. They were a nightmare to fix when the tuning went sour. There is a constant current source which feeds the 43 resistors in the keyboard string. The keyboard contacts just shunt resistors to generate a 1 volt/octave output for all the VCO's etc. Setting up the tuning requires precision selection and tweaking of the resistors, and any problems with the keyboard contacts or any resistor in the chain affects the tuning.
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Back in the 70's, I did some work on a Mini-Moog (Model D) for a music conservatory. They were a nightmare to fix when the tuning went sour. There is a constant current source which feeds the 43 resistors in the keyboard string. The keyboard contacts just shunt resistors to generate a 1 volt/octave output for all the VCO's etc. Setting up the tuning requires precision selection and tweaking of the resistors, and any problems with the keyboard contacts or any resistor in the chain affects the tuning.
For the technically minded.