AW: Cloning the SSM2040 (was: SSM vs. CE

Haible_Juergen#Tel2743 HJ2743 at denbgm3xm.scnn1.msmgate.m30x.nbg.scn.de
Wed Jun 14 22:05:00 CEST 1995



> > I'm sure we could build a discrete replacement [of the 2040].
>
> That sounds very interesting! I'm willing to contribute, where do we
> start? Should we try to contact the original SSM designers? Who are
> they? Dave Rossum? You mentioned that you had been speaking to this
> guy at Voce. Was he involved in the design process? Was the design
> info transeferred to PMI and Analog Devices when SSM was aquired?

No, Dave Amels (from Voce) and I were talking about CEM3320 filters.
But going back to the roots of E-mu (and perhaps SCI) would be the way.
I can hardly believe that there is no one around in the net to know about
that. I rose this topic from time to time, but alas, not a single reply to 
really
could bring me closer.
What the hell is this circuit like, that is supplied by +/-15V, but has 
output
voltage limited to +/-1V ?? I thought about a very basic OTA with only one
current mirror (i.e. the output is directly connected to the collector of 
one
of the input transistors, like the (simplified?) schematic for the SSM2024
shows in the data book - but *this* kind of output stage usually needs a
virtual gnd summing node or a very small resistor for output voltages in the
some-hundred-mV-range. (I think that's the case with the SSM2044, too.)
But what about this +/-1V output capability of the SSM2040 ?? I think this
limiting characteristic is crucial. The 2040 sounds best with quite a lot of
overload! (But it can sound very smooth with "normal" levels as well.)

Any hints welcome, really!

JH.

 



More information about the Synth-diy mailing list