the box contains a circuit which reduces the voltage for the gate (the synthi needs about 4-5 volts to trigger while the Roland sh-101 for example outputs 8-11 volts.)
and two trimmers for accurate adjustment of the CV to 0.32 volt/octave which is quite different in the synthi , from the common 1volt/octave method. the box connects to the synthi with the 8 pins jones socket which i purchased separately.
i also applied an op-amp 'voltage follower' in the box , which makes the gate pulse more 'stiff' and acts like a buffer. that circuit alone needs a power supply but since i didn't want to modify my synthi or my sh-101, i used an internal 9v battery in the box which powers that circuit and a switch to enable it. apparently this wasn't a good idea since the voltage follower doesn't work OK. i will probably need to power it from an external power supply.
the box contains two CV and one gate inputs , one LED for the gate activity, and a switch to swich off the power for the voltage follower circuit. it works great with my x0xb0x (the sh-101 still outputs too much current i think, the sound is a bit 'dirty' with it, like its combined with another more 'silent' oscillator.
the x0xb0x can act like a hardware sequencer for the synthi , or , if connected to midi it can hook up the synthi to the entire system, using a regular midi keyboard or software sequencer.
the box was made with mahogany wood, and black acrylic surface - just some leftovers from other projects...