ms-20 modifications

DJMaytag djmaytag at
Tue Sep 24 07:20:48 CEST 1996

i've finally gotten around to opening up my ms-20 and i've been thinking
about adding some extra patch points and a few other things to it, more so
now that i see how much space is available inside the beast (you could fit a
body in there the thing is so big). i'm not exactly sure how to do
everything i want to do, so i've got a few questions.

first big question: there's a big metal (aluminun?) bar across the top of
the circuit board. is this a heat sink of some sort? and does it HAVE to be
there? sorry, i guess that was two questions.

anyway, these are the things i want to add:

        VCO1 audio output
        VCO2 audio output
        ENV2 CV output
        VCO1 PWM by LFO (a la ms-50) input (is this even possible?)
        LP VCF audio input (input between the HPF and LPF)
        and an extra input (w/ amount knob) for the filters and VCO's

        i'd also like to mod the speed range on the LFO, if possible.

anyway, i'm ordering the schematics tomorrow, but even with the schems, i'm
not exactly sure how to add/mod these things. i'm sure the VCO audio outs
would be no problem, just do 'em like the 606 indy outs, right? it seems
like the outs wouldn't bee too much of a problem, but the ins are what i'm
not exactly sure about. if anyone has any advice or experience they'd like
to share, i'd greatly appreiciate it.


djmaytag at

three things to remember about me:
1) i'm not a dj, (but i play one on TV)
2) i have no intentions of becoming a dj, (or an actor)
3) i'm not a washer and dryer repairman either

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