SergeModular

> > I don't believe there *are* any manufacturers models for the
> > 3900/3401 out there.
>
> I suppose an email to National Semiconductors (2900/3900) or
> Motorola (3301/3401) might be worth a try. Or try Bob Pease (c:

Actually contacting On Semi might be worth a shot (years ago - I think it was them - they were nice enough to provide an old app note, for the MC1495 multiplier, I think it was, which wasn't online at the time).

Nat Semi, in my experience, are a bunch of tossers! Again, some years ago I contacted them as there is/was a blatant error in their LM741 model - their support staff wouldn't even put my query through to their engineers, as I wasn't building a 100,000+ component/year's worth of business for them. Unfortunately in a fit of pique I deleted their condescending email - I really wish I had kept it now. Compare this to Phillips: when I spotted errors in one of their models, it was corrected at their website within about 2 days!

As for the Bob Pease suggestion, LMAO at the idea! :-)

> It's on my reading list, which is longer than my remaining
> life expectancy...

You have that problem too then?!

> The same circuit crops up in several first generation Serges,
> including the Neg, Pos and VCO. I tried strapping a decent
> current source to the VCO and it was much improved.

Maybe its poor control of the associated parameter contributed to its downfall as a useful 'circuit element', in favour of better methods?

Tim
__________________________________________________________
Tim Stinchcombe

Cheltenham, Glos, UK
www.timstinchcombe.co.uk