Hello Rich,

What do you mean with "main clock source" There are various clocks in a
synth like the OBXa. In a first look I find at least two generators in
sheet 1 of 3 for Upper Control Board in the service manual Rev. 3. One
of them is the normal CPU clock, the other drives the !INT, which is
assumingly the mainclock for the S&H stages.

Mux/Demux systems for modulation amounts run quite often on clocks,
which run independent from the CV-to-S&H-Demux clocking (I'm not sure
the OB-Xa uses such a concept anywhere).

Florian

Am 23.02.2015 um 08:55 schrieb richtrix@... [oberheim]:

>
> Random question. Anyone know what pins on which component I can find
> the main clock source for the whole unit I have access to an
> oscilloscope to read it with just don't know where to look. I know it
> will probably be on the main processor on the UCB though. Mine is a
> late model OBXa and suspect the clock may be a different speed than
> earlier units.
>
>
>
> Most Sincerely,
>
> Rich Clarke
>
>