[sdiy] Spice model for CA3080 OTA

[yves usson]

Hi

A friend of mine bought a built one based on AM PCB and it was not 
working (same as you described),
he returned it and had it replaced by a new one. This one seemed to work 
for about 10 minutes and then
muted completely. This friend asked me to fix it. I tried various things 
(replacement of ICs...) and run some
measurements and got the same as you. No signal at the first OTA output 
and the outputs of the OPAs are stuck
to the negative rail. I was starting to suspect a bad PCB but what you 
say about breadboarding let me think
it is more a general design problem. The only thing I have not tried is 
to replace the OPAs by  old 301s as in
the original design.

Yves

Le 16/10/13 05:50, Pete Hartman a écrit :
> I'm looking for a CA3080/LM3080 Spice model.  I'm troubleshooting a
> few ARP 4023 filters that all seem to exhibit the same basic problems,
> AND building it on a breadboard (albeit with slightly different
> values/components because of what I have on hand) I get the same
> results--no sound.  Not on the output, not on the end of the first
> filter stage, nowhere other than the input.  Between the breadboard
> and being told that this same PCB has been built and worked, I don't
> expect I have a circuit board problem.  I didn't do the builds myself,
> BTW.
>