[sdiy] WASP filter

[JH.]

There have been a lot of publications which showed how to use CMOS
inverters as opamps in filters. The idea was that, while a CMOS gate looks
pretty bad in DC gain and output impedance at DC, the situation was
reversed at the upper end of the audio spectrum - if you compare them
to cheap 741 or LM324 opamps.

The Wasp expanded this idea to voltage controlled filters.

At least that's what it appears to be.

I haven't investigated if the Wasp predates these other publications or not.

JH.



----- Original Message ----- 
From: "Aaron Lanterman" <lanterma at ece.gatech.edu>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Sunday, February 19, 2006 3:57 AM
Subject: [sdiy] WASP filter


>
> > IMO a good combination is to use CMOS for the buffers, just like in the
> > famous WASP filter. Hi Z input, and ok-ish drive capabilities.
>
> I've always wondered - did the WASP designers do that because they had a
> brilliant idea for a cool new sound - or did they do it since they could
> get CMOS cheaper?
>
> - Aaron
>
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