Hi Stuart

> anyone here from auckland

David Bulog might be around here (though he is mostly an Roland addict).
And you should not miss to get in touch with Murray from kiwitechnics.com

> will the diy synth vca work for control signals or only for audio

I don't know

> i'd also be interested to know where in the circuit the resonance feedback is injected.

That is described in the owners manual: JP2, the pin is described as
"VCF RES IN".

> that's probably one for dieter, or is the schematic out there somewhere

I'd be interested in the schematics too.

Florian