SH-5 helper box

SH-5 with helper box in the near darkness

Instead of putting the Juno-6 DCB/MIDI converter thing in a box, trying to fix the envelope and chorus noises in the Jupiter-4 clone, or actually trying to make music, I made this helper box for my SH-5, which doesn’t get as much love as it should.

Basically there’s a switch on the front to allow me to flip between playing the synth from the keyboard or the CV/gate inputs, which saves all the faffing about around the back. Also there’s an attenuator for the VCF mod CV input, and as a bonus prize, the switchable portamento nicked off the MC-202.

Here’s a demo! Only I don’t do very much demo-ing of the actual box, oh well.

Bass is System 100, strings bit is JX3P, drums are TR-606 (and I need to start using something else, because I think I’ve worn the 606 out for now). The MC-4 is varying the VCF CV a bit, and I’m switching the portamento on and off using the MPX output on the channel.

Here’s the portamento stripboard:

SH-5 box portamento stripboard

I’d publish the layout but it’s all wrong, the Kicad symbol for the LM317 that I happened to pick had a couple of the pins swapped – luckily I noticed before I soldered it up. In the end the simplest thing to do was to insulate one leg and just bend them round into place.

It’s run off 12V DC, regulated down to 9V by the mini LM317, so it won’t cover the full 10.67V of the MC-4 but pfft, I can live without that octave. The LM358 won’t quite go down to 0V either, but the SH-5 goes low enough anyway from the octave switches, it shouldn’t be a problem.

Here’s the mess inside: just ram it all in, it’ll be fine:

SH-5 box innards

…although I did insulate the base and the back of the circuit board.

I cut two holes in the front by mistake, so I bunged a power light on there (always forget to do those usually, they’re handy) and just a LED lens to cover up the other one. I wished I’d included a LED driver to show when gate or MPX was on, but there wasn’t a lot of space. I got lucky that the board fitted vertically in the pedal box.

Speaking of which, I love these Hammond pedal enclosures. Even though they’re a bit boring looking. Maybe I should’ve bought one of the bright orange ones instead.

Anyway it’s good to integrate the SH-5 a bit more. Also I could do with some sort of mega-switch-box as well so I could flip between triggering synths from the MC-4 without having to unplug things. One for another day. Probably I should actually try and make some music as well.

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