two questions

[Rob Rickner]

Um, two completely unrelated questions her.  First, I want to use to
dual op-amps in the place of one LM324 for one of tomg's CV-Mixer
circuits, It's for two, I need one.  Second, in Marston's Audio IC users
handbook there is an equation-
FrequencyC=1/2piRC could somebody please explain what the units are.  is
resistance in ohms or kilo-ohms, is the capacitance in farads,
microfarads, or what?  Is the frequency just in Hz?  It's on page 30.
Also, does anyone know anything about the AM circuit on page 53?  Are
both inputs in the audio range?  And, in response to the request for a
VCA that runs on +/-9volts, the same book has several.
Rob Rickner cut/generic
PS, thank you to everyone who helped me out on my last couple of
questions.