I've tried to be helpful here a few times, and now it's my turn for help, and I hope I've stacked up enough good Karma in this case:
I've got two of these boards that came in with a pile of Moog Satellite parts I purchased awhile back. I knew of three different revisions of Satellite main boards, but this is a fourth, apparently later version for which I cannot find ANY info. The boards are obviously rigged for use inside a Thomas or CDX-0652 (White Elephant) organ, and the low-pass filter section and "modulator" section is completely different.
First, the "Standard Board", from a normal, non-organ-installed Moog Satellite:
And the section of the normal Satellite board relevant to this post:
Now the "Mystery" board:
And the relevant section of the "Mystery" board:
It appears at first glance that the normal low-pass filter (which is actually a 12dB Moog ladder) has been replaced by an OTA-based 12dB filter similar to the main VCF. I probably could flip it over and trace the circuit in my "Spare time" (yeah, right ) but I have become a bit lazy in my old age.
If anyone can offer any assistance, info, or even a link to a service manual that addresses this version I would be most grateful.
By the way, I've been working on three different Satellites and a Minitmoog, and in the course of doing so I have found MANY errors/differences in the schematics and parts list. As soon as I wade through all this stuff, I plan on posting some corrections later. One thing I'll mention up front in case anyone is considering using a main board from a Thomas Organ inside a regular Moog Satellite: It WON'T WORK without quite a few (albeit easy) modifications.