MIDI Pedal Board, the electronics

Continuing from part 1 of this project, I’ll run through what I did to get my MIDI Pedal Board to more than just a (nice?) shell. All that stuff which makes it tick!

The case, all good to receive electronics!

Roland JP-4 IO Mod

For ages, I’ve badly wanted a MIDI mod for my JP-4, but the urge hasn’t been quite Kenton-bad. Needless to say, when I came across the Roland Jupiter-4 IO mod at the Jupiter forum sometime this february I was pretty amazed.. and shortly after, a kit in the mail! Kinda difficult to say no to a cheaper kit with better features.. ;)

Installation was a breeze and the added functionalities also gave me a possibility to receive a bit of RTFM from Laszlo (the creator of IO mod kit). Contrary to the installation instructions, I chose to drill holes for the MIDI connectors where the audio jacks are. There’s a relatively pointless warning plate right above the jacks and just so as it happens, the plate is about the size of two MIDI connectors. If the mod had to be removed, the drilled holes can be then covered with the original warning plate. Anyway, for the connectors to be installed like this, their cables had to be replaced to match the new location.

Boards and cabling installed

MIDI connectors

Not much else to say about this kit than recommend getting one if you have a JP-4 :)

MIDI to DIN sync adapter

A quick one to construct, upon stumbling across Colin Fraser’s adapter, I just had to give it a spin.. Here’s his description about it:

..details of what may be the smallest, lowest part-count MIDI to Din / Din to MIDI Sync convertor about. A big advantage of this design is that the circuit uses so little power, it can be reliably powered from the MIDI output socket of another device. The disadvantage is, it won’t cope with a PC that sends very irregular MIDI clock pulses, so YMMV.

..eventually, I ended up constructing two :). MIDISync1 was built to perfboard whereas MIDISync2 was built with sockects and parts only. The latter was moreover a test of “how compact I can make the adapter” and thus isn’t as sturdy as MIDISync1. The only “frame” MIDISync2 has are the two DIP sockets glued together and one could easily break it by twisting lightly from both DIN connectors. If the connectors were bridged with long screws or the whole unit was encased, the construct would be more solid of course.

Not much to it, so here’s what my adapters turned out like:

Top view of MIDISync 1

Bottom side of MIDISync 1

Top view of MIDISync 2

Bottom view of MIDISync 2

Colin’s page about the adapter is here.