design philosophy was: (Compensating multi-stage feedback)

[tomg]

We ain't talking (Compensating multi-stage feedback) here...

That's fine for stuff  that does not need the opamp topology but I
think you guys are missing the point here. This is a building block
circuit that can be used for just about everything. Outside of the
EGs  ( and that's just because I haven't gotten to them yet) a
complete set of synth components can be built using the core of
the  circuit I posted yesterday (with a few small changes and a fet
here and there)...

The point is this.... There is more that one way, to build anything.

So here is *my* bottom line. Just because my favorite supplier
doesn't carry CEM3340s, SSM2040s, LM13600s, CA3280s
or "whatever"....I can still build what *I* want with what *I* have....
Anybody paying attention out there can too by now.  So I've done
my part....If you get it great! If you don't....sorry I can't help.

Tom



> >Bottom line for *me* is that until I see any groundbreaking article
> >on that subject, I'm either using integrated opamps, or
> >(and with increasing pleasure) discrete circuits that don't use
> >multi stage feedback at all. It's astounding how many
> >functions in a synth do not need the opamp circuit topology
> >(integrated or discrete) at all.
>
> 100% agreed. I'd even go one step further: The complete audio path can be
> done without negative feedback. (And hence no compensation.)
>
> The FET circuits we've seen lately were mostly not feedback (at least not
> over several stages), but still have very small THD. Devices with a square
> law characteristic (triodes, FETs) allow it to cancel most of the even
> order harmonics by symmetrical or push pull arrangements. And these
devices
> generate only smaller ammounts of odd order distortion, compared to the
> exponential law for BJTs.
>
> IMO much of the "transparency" and "resolution" that is attributed by
> audiophile circles to these kind of circuits has to do with the absence of
> multi stage feedback.
>
> Bye,
>  René
> --
> uzs159 at uni-bonn.de
> http://www.uni-bonn.de/~uzs159
>
>
>