[sdiy] Polyphonic temp compensation in VCF's!

[Tom Wiltshire]

On 24 May 2011, at 18:57, David G. Dixon wrote:

>> I once took my Polysix around to friends house on a cold 
>> winter's day. Although it was only outside for five or ten 
>> minutes or so when I arrived the tuning was unplayably bad. 
>> And there's no autotune on a polysix...
> 
> Are we talking about VCFs or VCOs?  Were the Polysix's VCOs
> temperature-compensated, or were you using the VCFs as quadrature
> oscillators?

It was a long time ago. I only remember the very-cold-then-warmed-up Polysix going "Blong! Bling! Blang!" when you pressed successive notes - i.e. the voices were no longer close to identical.

Florian's point about the single exponential convertor is very pertinent, since that suggests that the problem was mostly from the filters drifting. Which is what we were talking about - crumbs!

T.