[sdiy] parts watch

[Grant Richter]

> You could go the the voltage divider design and just live with the small
> amount of tempco shift that gives you, or you could go to slightly smaller
> input resistors (91k ?).

According to good old Electronotes, the theoretical point is 18 millivolts
per octave at room temperature. (100K/1.8K) I know that is only an
approximation. You could always trim the resistance at the input rather than
the output (91K in series with 20K trimmer?) for exact 1 volt per octave.

Otherwise a 56K over 1K tempco the the expo trannie base gives good
performance with an input stage gain trim.