[sdiy] VCO IC

[Paul Perry]

The original ICL8038 was a pretty flawed concept (though Thomas Henry
managed to get it to behave, with some ingenious workarounds.. anyone have
the circuit up anywhere?).
Whether the XR-8038A is better behaved I dont know.
Certainly, the XR2206 was a better thing to use, if you wanted a VCA in
the audio range. I'd rather use one of those for a signal generator.

But the other thing wiht a signal generator, is that you might be better
just
making a 'standard' synth VCO, with a octave/V control, because then the
frequency control is not cramped up one end. For a signal generator, you
don't have to worry about the temperature compensation either.

My favorite audio sig generator is the one in the LM13600 notes, doing the
triangle/square, with another (carefully overdriven) half of a LM13600
distorting the triangle to a sine.
With an exponential converter supplying the control currents, you get a
great sweep.
The sine is just as good as a 8038 too (about 1.5% error)

paul perry Melbourne Australia