[sdiy] New Vco

[tomg@efm]

Hi Rene, Neat! I did a quick proto-board works ok. Seems to
go flat about 3 octs.... and I couldn't get a saw output.

It's not really new though...Roland used something much like it
it 1980 for the MRS-2. It was very convoluted running to a 555
and back to a 4052 for division.

They used a much simpler version for the MRS vc-adsr.. You
may remember I posted it a few years ago......anyway here's
something you may want to look at.  It's good for a little over
4 octaves....It doesn't have a true saw out ether. I can give it
one but it cost another opamp and fet....might as well build
Terry's vco at that point.

http://people.atl.mediaone.net/efm3/vco-mrs-1a.pdf

Tom



> Hi all,
>
> I've put up a new VCO design. Based on a 4069 hex inverter
> and tree transistors. No difficult to obtain tempcos and yet
> compensated.
> A more detailed description and some constructional hints
> are located at: http://www.uni-bonn.de/~uzs159/vco4069.html
>
> Have fun.
>  René