[sdiy] Cheapest, simplest but still reliable VCO & VCA for polyphonic project

[Karl Ekdahl]

Hi list, so i wanna make a poly synth and as usual i'm looking for the cheapest possible VCOs and VCAs that'll still cut it. Note; i'm not after absolutely perfect pitch or anything, in fact i'm going analog to avoid this.

>From what i can see online the simplest okay option seems to be the ASM-1 style VCO, yes? For this design, how important is it to use a ca3140, i've seen similar designs using standard TL0XX opamps. Also i've seen design using LM394 instead of MAT-02 and recent discussions have even suggested that any discrete transistors from the same batch are matched enough for it to work straight-off, is this true for a poly synth? As for tempcos, is there a big difference inbetween 3300ppm and 3900ppm, my experience tells me that SMD is good here because you can very easily glue the resistor directly to the transistors with very good thermal contact - any sources for these? Anything else i should think of?

Next question is in regards to the fact that since i'm doing a poly synth where one set of knobs controls all the voices, i'll have to make *every* parameter voltage-controlled, so i'll need a hell of a lot of VCAs. Any suggestions on good, cheap and very low parts-count VCAs? I'm guessing a LM13700-design.. ?

Thanks

Karl


      __________________________________________________________
Låna pengar utan säkerhet. Jämför vilkor online hos Kelkoo.
http://www.kelkoo.se/c-100390123-lan-utan-sakerhet.html?partnerId=96915014