Message 599From: "Steve Ridley"
Date: Fri Dec 26, 2003 8:09 pm
Subject: Re: [resergence] Quick VCA/VCF Submodule Question


The VCA submodule schematic shows one of the opamps with a 47pF cap in its feedback loop, the other with one that's 82pF. The actual PCBs show 47pF in both positions. Should I stick to the values on the schemo or is OK to use two 47 pF caps?

The one I saw has 47p in both positions and the one Dean looked at had 47p and 82p. I don't think either of us made a mistake, so it seems both versions exist. The question is why. Either it was one of the many changes or upgrades that Serge made over the years, or he used different values depending on the type of module (and the position within that module).

I think the first explanation is the most likely, but I don't know whose sub-module was the most recent and what modules they came from (mine were two "orphans").

I'd go with 47pF but watch out for any signs of instability.

Steve