tri2saw (was:commercial synth circuits)

[Tim Cockram]

In message <1BF5E20E0C4DD111BBAB00805FE2D582979119 at nbgm336a.nbgm.siemens
.de>, Haible Juergen <Juergen.Haible at nbgm.siemens.de> writes
>What about this method (haven't tried it yet):
>Build a triangle VCO, and use an additional transistor 
>(matched) in the expo converter to get a second control 
>current. Use this current to charge a second capacitor,
>and discharge this capacitor every time when the triangle
>has a positive zero crossing. Shouldn't use more components
>than other converters, and all you get might be a little amplitude
>error in the saw wave.
>
>JH.

Good Idea
The Aries modular used this method quite succesfully.

It can be extended to do more bizare stuff too, especialy if you include
an independant reset circuit with a soft /hard sync input:- sink half of
the current... Sub octave,  1.5 times the current +5th, 2 times the
current octave up, or add offsets for linear detuning

It's quite easy to build a "fat" Moog 901 type oscillator bank (with all
of the ideosyncracies too). 
-- 
Tim Cockram