[sdiy] Saw (not) TRIANGLE to Sine Converter PCB

[Peter Grenader]

Over the weekend, feeling the need to keep up with you guys, I built Jorgen
Bergfors' sine conversion circuit - the second half (sine conversion), and
drove it with a triangle wave from my newly-built Mark Verbos-modified
Buchla 258 circuit.

There is a tranny output midway through that VCO circuit that givesoff the
sweetest triangle wave known to man - figured it was a good place to take a
sample.

I had a couple of part sub required (the cap and resistor values in the
feedback loop of the output), but once I got it dialed in, itsounded and
looked as clean as anything I've seen.  One of the purest sines i've scoped
in a long long while.

I am having a slight problem though which I think is an after effect of the
part subs I made -->  the amplitude at the output tracks the VCO frequency
to a certain extent - weird.  At a certain point, about 1 k hertz, the
higher the VCO frequency driving the circuit, the less the amplitude at this
converters output.

it gets down right hard to hear up about 12 k.  I'm working on a fix, but
other than that, I am pleased as punch.

best,

Peter