design philosophy was: (Compensating multi-stage feedback)

[René Schmitz]

At 14:03 30.06.00 -0700, tomg wrote:

>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. 

Until enough people catch on with the 2SC1583, so that stock gets low. ;-)
Replacing the opamps in circuits with discrete opamps (well sort of) isn't
really that much of a new way of doing things. As you say its replacing one
building block with another.  And I think monolithic opamps will live as
long as there is a need for analog circuitry. But dual transistors will
eventually be more difficult to come by in the future. And maybe even lead
mounted singles pose a problem in a few decades....who knows?!

My point is not a single module in the audio path needs the opamp topology.
(Or more generally strong negative feedback amps.)

>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)...

Right, the diffamp is the key building block here. As it is in every opamp
or OTA.
One can build an entire synth out of nortons or fets or optocouplers or
just tubes. The point is always: Will this have interesting and new
properties?

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

Yet, there are more "revolutionary" ways and more "traditional" ways.
(I'd characterize traditional as using differential pairs. Either in OTAs,
opamps etc or in discrete form. I can't remember a circuit where none has
been used.)

>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....

Right! And I think its great, if you can find circuits with interesting
properties and sounds previously not archeived. And if not, then its still
fun!

Bye,
 René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159