> From: Eric Frampton
>
> Yes, when forcibly enabled the channels sound completely
> normal otherwise.

Other question: when you forcibly enable the channels, does the first
oscillator sound in tune? I'm wondering if it gets part way through the
process on each channel before failing, perhaps failing on the pulse width
or the filter. If oscillator 1 is sour, then I'd concentrate on the "Timer
Interface Serial I/O" section. If it is in tune, then the problem may be
elsewhere.

The auto-tune measures the period at four pitches for osc 1, then osc 2,
then the pulse duration at two widths for osc 1, then osc 2, then the
period of filter self-oscillation at two pitches. Sometimes you get a clue
by where it fails.

If you need help figuring out the Timer Interface Serial I/O section, let
me know. Or, if you have spare parts, you could try replacing the ICs in
that section, and hope that fixes it.

--

Ciao, Paul D. DeRocco
Paul mailto:pderocco@...