[sdiy] Buchla Lowpass Gate Switch

[harrybissell]

The S-K filter is absolutely famous for severe interaction with the
input level...
especially in mid to high rez applications.  Personally I find it to be
a "touch tone
telephone" sound (before the FCP was invented :^)...

You might have even interfered with the overall Q of the S-K filter by
making those
resistances too radical.  Also possible that the mismatch between cells
caused an
artifact ???

One thing I can say for the LPG...   it has some amazing sounds for an
economy
of components !!!

H^) harry

Peter Grenader wrote:

> Well, I'll tell ya...My average signal strength in my system is
> somewhere around 7 volts. A Buchla's what - 2?  The thing was kazooing
> like a banchee in medium to high res configurations.  So, using a
> divider I dropped the amplitude at the input to 2 volts, then brought
> it back up at the end with another op amp and .... problem gone.
>
>
>
>
>
> I dropped the amplitu mark verbos wrote:
>
>
>      I still think the distortion is from somewhere else in the
>      circuit. Those op-amps have a fair amount of gain in the
>      middle there. Especially at narrow bandwidths, I think you
>      may have been railing them with your 10 volt signal.
>      Remember that the circuit is intended for line level.
>
>      Mark
>
>
>      Peter Grenader wrote:
>
>           Re: [sdiy] Buchla Lowpass Gate Switch I was
>           unclear.  I was meaning if you overdrive a vac in
>           general, not necessarily  in this circuit.  I've
>           did it on my 291 clone.  I had to attenuate the
>           input a bunch so it wasn't kazooing on me and then
>           bring it back up to volume on the other end.
>
>
>           mark verbos wrote:
>
>
>                wait a second.... overdriven? Isn't it
>                just a resistor? Something else int he
>                signal path must be causing that, no?
>
>                Mark
>
>
>
>                Peter Grenader wrote:
>
>                     harrybissell wrote:
>
>
>
>                          If you are looking
>                          for "full on" by all
>                          means blast as many
>                          photons as
>                          possible... but
>
>
>                     Careful on this.  Vactrols
>                     make anything going through
>                     them sound like a
>                     kazoo when they are
>                     overdriven.
>
>
>
>