[sdiy] OTA performance (was SSM chip reissue)

[Roman Sowa]

The idea of using zeners is to limit the signal inside the integrator 
and keep it away from overdriving it that leads to nasty squeeky noises 
out of tune. Doing that outside integrator is totally different approach 
of keeping SVF stable, more like addition of diodes in the feedback of 
the filter.

Roman

W dniu 2017-04-26 o 14:02, Andre Majorel pisze:
> On 2017-04-26 10:06 +0200, Roman Sowa wrote:
>
>> At low cut off frequency, when integrator currents are really
>> small, Zeners are damping the oscillation, because most of the
>> current is eaten up by the zener, not the cap - at that small
>> current their voltage is way much smaller than, say, at 1mA,
>> the top of VCF frequency.
>
> Any possibility of putting an op amp between the BP output and
> the Zener diodes to buffer the signal ?
>