The book!

 The Book of MIDI: A switchable MIDI to CV Interface.

  • Built from the PAIA MIDI2CV8 Kit
  • 110VAC operation
  • Provides 8 configurable (through onboard switches) Gate and CV outputs


I had built the DelphiChord synthesizer and a CV Keyboard for it. The problem I faced was that 99% of the keyboards and sequencers these days are MIDI controllers. I researched building my own, and this is very feasible. They are not that expensive to make. At the time, I was also designing the Slingerland Drum synth and was trying to figure out a way to trigger all those gates, etc. and use it for all the other synths I was planning. I did not find a decent DIY MIDI interface schematic design that I could program and allowed me to use it for any analog synth I build. But I did find an entire kit, you can build yourself, that had that functionality. It still falls within the DIY, but all of the parts come with this so there is a premium you will pay for having everything supplied. I generally stay away from complete kits, because I like to source my own components. The kit I got was from PAIA, a long established DIY synth and electronic company.

At least this way I could still build it in some wacky container, so it did not look like anything synthesizery or technology driven, until you reveal it by opening it.

The Book standing up

So I found these boxes at a thrift store, that looked like old books. Really cool looking too. So I decided to build the circuit board inside. And then when you opened the book….. like all books…. it showed possibilities!

Opening the book reveals the interface

Inside the book

The face plate is made from the ton of engineered wood sub flooring I have. It takes a beating, cuts well and is resilient to water (for short periods). I made the artwork in a coloured copier and decoupage it onto the wood. Then drilled out the holes for the jacks and switches, etc. I also added some copper tape to assist in the grounding of the jacks. Even though they are wired, and backup is still a good idea.

This, IMO is one of the best MIDI 2 CV interfaces out there. You can configure the board to meet a variety of needs and trigger/CV types, just by flipping some switches.

  • Pitch and Gate control of 4 synth voices.
  • Pitch, Velocity and Gate control of 2 voices plus Pitch and Mod wheel CVs.
  • Pitch, Velocity, Pitch Wheel, Mod Wheel, Release Velocity, Channel Pressure, Gate and Re-trigger.
  • 8 CVs from Continuous Controller messages.
  • Analog Drum Trigger Mode.
  • DIN Sync – 24ppq, Start, Stop and Continue PLU

Wow! All that and a bag of chips! There is even an add-on board to change the whole thing from 1 Volt per Octave to Volts per Hz used by some of the synth manufactures. The kit is designed to be powered by an AC wall wart transformer (not supplied), or you can do what I did and just obtain (through salvage & reuse) a 110 to 13VAC transformer, along with a switch and a fuse. I also used a 3 prong inset receptacle for the myriad of computer chords you can find easily.