[sdiy] VCO that goes SHARP in highest octaves??
diy at artefacts.nl
Thu Jun 16 08:48:01 CEST 2022
Are you sure the problem is in the higher octaves, didn't you compensate
for a problem on the low end resulting in the oscillator going sharp in
the higher octaves? I had this twice with a Jupiter-8 oscillator, once
it was caused by flux and the other time by a leaky FET.
Op 16-6-2022 om 03:37 schreef Neil Harper via Synth-diy:
> On 6/15/22 21:04, Mike Bryant wrote:
>> I can't remember the original details or the circuit, but have you
>> tried replacing whatever creates the exponential conversion ? It
>> may be the gain of it changes at higher input voltages more than any
>> correction circuitry allows for.
> hi Mike,
> pretty much the last thing I haven't swapped out are the opamps,
> LM137000 and the matched pair transistors. At this point I've just
> accepted that there's a +10-20cent error at C8, because the transistor
> pair SMT package I used is VERY small and I can't picture being able to
> remove it and tack on some regular handmatched TH transistors to see if
> that fixes the issue..
> /// Neil Harper
> /// Every Wave is New Until it Breaks
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