Secret CEM chip info...

[Paul Schreiber]

There is a chip that was a "test bed" Doug used to breadboard the CEM chips before production. It is many little useful pieces of CEM circuitry on 1 part. In fact, Doug's homebuilt modular synth uses a boatload of these to do all VCO, VCF, VCA, EG, LFO and mixers. Most functions need 1 to 3 of these chips, plus the usual assortment of R's and C's. And yes, I will try to get a photo of his synth (it's in the garage under a green tarp).

There are quite a few of these available. I will get the handwritten "data sheet" and scan it in the website. If there is
interest, I will try to make the parts available. Don't know the cost yet.

If the CEM rebirth does not pan out (should know by March 1st, still time to get those requests in!), there are plenty of these to go around. In fact, I will probably sell them in lots of say, 6 pieces plus the data sheet.

The website will up by March 1st at www.why.net/users/paults unless I get madder at my ISP and move it. Currently having FTP problems (sigh..sometimes I really DO miss my Trash80).

I asked Doug about the SSM filter chip versus the CEM. They are in fact completely different topologies. The SSM is really a "cheesy" part that has 4 CA3080 OTAs and a rather crude exponential generator. It generates quite a bit of third and fifth harmonics, which explains the "fatness". Sometimes electrically "crummy" is "superb" mucically. Just look at the fuzz box schematics. Sheesh..... The CEM filters were designed to be "cleaner" from a THD+noise value, plus SSM had terrible yield issues which caused many synth designers to switch to CEM.

Thanks for all of the emails so far. Do date, I'd estimate that the interest level is 50% of needed response to remask,but I really won't know for sure for 2 weeks what the actual costs and schedule will be.

Paul Schreiber
Synthesis Technology
paults at why.net