I’m often in need of simple, dedicated circuits and out of utility, a recurring format has emerged. The Black Box Series is a growing set of utility boxes I have been making to augment my set-up and simplify signal/work flow.
These are all using Radio Shack’s tiniest project box.
One houses a meter that I found at a surplus store that was conveniently labeled “control voltage” so I used a resistor that sets +10/-10 volts at the extremes and use it to analyze control voltages on my modular synthesizer.
Another is a box I made to attenuate the output of my modular synthesizer. Rather than carry around a small mixer for this purpose, I built a stereo 1/8″ in/out attenuator. I usually send my signals to my Tiptop Audio Z-DSP at the and of the chain and come out stereo, then go through this box before going into a recording device.
The third is a box I made that allows my modular synthesizer to interface with an unmodified Synsonics drum machine.
Long ago I found a website that showed the pin outs for the 5 pin din socket on the Synsonics and this is clearly NOT a MIDI port. It has contacts for a footswitch accessory but I have made a box that just maps all four inputs/outputs to jacks. These functions are: Bass drum trigger in, high hat close gate in, bass drum trigger out, and 16th note trigger out. All super useful for modular use. I added an LED to show the kick drum trigger output. Above shows how I have it set up along side a Radel Digi-100 Plus tabla drum machine, which also accepts a voltage trigger input (it is meant to be used with another Radel product, but I have had luck using a fast clock trigger from my modular).
I should note that the bass drum and high hat trigger inputs are set up for footpedal use, so they are triggered when the positive pin goes to ground (when the circuit is closed, i.e. a connected footpedal wired ‘normally open’ is pressed). These will not accept a standard modular trigger pulse and behave as expected, but could be modified to do so. They will work with a gate, but the trigger occurs when the gate goes low, so it’s a little tricky.
Below is a short video of the test I did right after finishing the box:
PYRAPHONIC 