[sdiy] ASM-1 VCO section update

[Magnus Danielson]

Dear fellow Synth-DIYian,

I've just uploaded an updated ASM-1 description where I tries to
describe in some greater detail what is happening in there in the
VCO. Not everything is being described in detail just yeat, but I'd
like some feedback of how you perceive the road I am testing out, if
you like the style of the description etc.

I've also added a long overdue modification description which should
have been in the original curcuit way back in 96 or so. I hope the
rational for this mod is sufficiently covered in the text I just put
up.

Sorry for the ASCII formulas, they are not pretty, but they do the trick.

Cheers,
Magnus