NE 566 + have you checked out the 8038

[MACHINE MEDIA]

> One chip I am currently planning with is the 8038 Function Generator chip.
> This is a lot more versatile, with Sine, Square and Triangle outs. There is a 
> Sine wave adjust pin, and a Duty cycle adjust (which works for all waveforms)
> enabling Ramp both ways.

I've looked at that chip also.  Harris has an AnswerFax system (407) 
724-7800, both the application notes for the ICL8038 (#2864) and a 
document entitled "Everything You Wanted To Know About The ICL8038" 
(#9013) are available.  Perhaps, they have another number for Europe.
I had them faxed to me about a month ago, but I haven't actually ordered any 
of the chips themselves. They state temperature drift at 250ppm/C, but from 
what I can tell the duty cycle varies over frequency.  This is less of a 
problem if you reduce the frequency range -- useful musical ranges are far 
less than the .001Hz to 300kHz stated for the chip, anyway.

PEACE OUT :)
MARK