[sdiy] ASM-1 VCO questions--please help

[synth at charlielamm.com]

I am slowly getting this to work but still have a few issues.

1) Pitch of VCO when summing opamp is set to 0V rel. to ground doesn't
seem to be working correctly. I have read in the archives that the VCO
should produce a frequency of around 900hz when there is no modulation
(which I read to mean: Pin 1 of cntl op amp summer, or the "op amp" side
of the 56K resistor R13, reads 0V on fluke)

My VCO produces more like 6K.

2) The thing won't scale.  It goes up in pitch when I play my kbd, but I
can't get it to track evenly beyond 1 octave.  Maybe related to issue 1?

3) I have tried adding a 10K trim in series with the 150K resistor to give
a high-note tweak.  No help.

4) This is my own board layout.  I am willing to entertain that I "didn't
lay it out correctly" although the basic functionality (ramp + pulse out,
PWM, PW, general behaviour of the VCO) seems to be OK.

The thing just won't scale.

Any suggestions?  I am using 1% for all resistors in the exp converter and
5V ref for the comparator.  Everything else is 5%.  I am using a 22pf
ceramic cap for C3 and a 2n2 Mylar C2.	I am using a 1K 1% metal film
instead of the tempco.

Thanks!