if you mod them onto sockets, what do you get? and that's a lot of sockets if you want access to all of them. presumably all need TS connection, with sleeve attached to ground.
alternatively, could you just take the signal out to a breadboard, or patch into the Volca Modular?
Or patch back into the internal circuit somehow? eg: doing mods? (if so, such as?)
i've just drilled 5 holes in the back of my Keys

s'ok, i did a pretty clean job. but any suggestion that these cases were designed to take the average stereo minjack socket is a lie. you have to dremel (small dremel..) the moulded surface to get the socket to sit flat against the rear, and find low-profile sockets that fit under the pcb.
the plan was really to just add a MIDI out socket but i got a bit carried away.
so what have we here? ...
VCO out (?)
VCF out
VCA out
SQR1/2/3
SAW1/2/3
and 2 reset pins.
and they put MIDI VD/TX/Grnd in a really awkward place on this one.
any point in considering some switches? (make it even more of a swiss cheese)