Are you sure about this? In Chamberlain's "Musical Applications of Microprocessors," a VCO calls for a Q81, which is labeled in the schematic as a 2k resistor. Ryan > I assume that the Tellabs Q81C is no longer available, and I'm not sure what > to substitute for it, as it's a 1K device. The tempcos I see these days are > 2K devices. Hmmm...