Temp. compensated VCO

[Henri Kovalainen]

 The board pic is now available at

 http://lyseolukio2.kajaani.fi/~dh/compvco.ps

 I found out that (at least in my case, it was around 0.5v) the saw
 amplitude varied quite much. So you might have to twiddle the feedback
 resistor (470k) on the buffer amp (which also sums the offset trimmer).
 The squarewave is generated with an op-amp comparator, so purists may
 find it to be too slacky, but it was good enough for me. I haven't had
 any latching problems with the comparator, but (supposingly) the
 compensation amp config has latched a couple of times when I have whacked
 it with a hard negative pulse from a lfo etc. Also a small negative spike
 might be present at the bottom of the saw wave, which didn't bother me,
 and if I ever design a waveshaper board for this one I'll include a
 clipping amp that will shave these off. The resistors values it the cv
 summing amp depend on which way you hook the pitch pots. I didn't connect
 the arrays leftover tranny to the negative rail (this was suggested in
 Rene's schematics) which hasn't caused any problems that I'm aware of.
 Hop, skip and jump with a wire if you want this to be done. I have used
 IRF530s instead of BUZ20s too, and they all seem to work properly.

 Also, I would like to point out that only proper feedback is appreciated,
 any criticism or flaming is ignored and therefore futile.
 If you don't like the design, skip it.

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 ianoftrueliberty. |  http://lyseolukio2.kajaani.fi/~dh
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