Casio sk-2100 -Ranting about breakout boxes

[sk-1]

The problem being that two of the mods are directly in the signal path and without the extra controls in place the synth just won't work at all. The second you removed the breakout box the SH101 will just stop.

I thought about that problem too, believe it or not.  With a breakout box I totally see how having a DB-25 connector would cause the circuit to be left permanently open, or permanently stopped, as you put it.  The only way to overcome that problem would be to plug in a loop-back plug/dongle that would allow the circuit to follow it's original path.  But because that would just create the hassle of having another task to perform in order to have the machine operate in it's default-mode, I would consider installing a switch and wiring the loop-back internally.  So for example; if I wanted to use the break-out box, I would flick the switch to open the circuit and plug in the break-out box.  This procedure would close the circuit again but all my circuit-bending controls would now be connecting the circuit together, allowing me to bend it.

It's a solution that would work, but it's a little complex to implement so it would take some extra planning and designing of course.  The nice thing about mounting the controls directly on the surface of the toy/instrument is that it makes the design more simple and easier to install.

Its like buying an original 1956 Les Paul Goldtop guitar and sticking it in a vault to wait until it becomes worth more money. These things are instruments, they are made to have people mess around with them and make weird noises with them. Just make some noise.  

I see what you're trying to say.  I know I shouldn't be putting so much emphasis on it's condition but plenty more on it's playability... which is where circuit-bending comes in and increases that particular factor.  I feel I need to start a pile for bending so I have something to cut my teeth on first.  I dont want to rip into my nicer boards until I feel I am skilled and experienced enough to build a top-quality, professional looking circuit-bent keyboard.