[sdiy] SEM filter questions

[Tom Wiltshire]

On 22 Apr 2012, at 13:37, Doug Terrebonne wrote:

> 
> 
> --- On Sun, 4/22/12, Tom Wiltshire <tom at electricdruid.net> wrote:
> 
>> The OB-X is about the point at which it changes over. It
>> retains the CA3080 SEM filter, but the oscillators and
>> envelopes are already CEM chips.
> 
> No that's not correct. The only CEMs in the OB-X are the CEM3310 EGs. The oscs are 3046 based.

Sorry, my mistake. I've checked and you're quite right. 

> I have all the OBs right here. :)

Lucky you!

It's very interesting to see the evolution of the Oberheim designs from the SEM through the nearly-SEM OBX to the nearly-CEM OB-Xa and OB-8, all the way to the two-chip CEM voice (3374/3372) of the Xpander. It's a fascinating story, told in synth service manuals!

Tom