Making The Spacehorn

Okay, so basically we’ve got two components: an Akai EWI USB, which is the cheapest member of the Akai EWI family, designed to be used with dedicated laptop software, and the Axoloti board.

The Axoloti is of course a virtual modular synth, not unlike the legendary Nord Modular. The first task that anyone who buys one needs to consider is building a casing for it. Naturally, I cheated: I found a building toy called Polyconstructo in a charity shop in Muswell Hill and attached the main board to a box made from that: it was also a useful chassis for attaching the four (analogue) knobs which I wired up to the board.

Creating a hypnotic engine

And then there was the 7 segment display: I ripped this out of an old MIDI controller and started thinking about how it could be deployed in a non-utilitarian manner: not to display data but as a hypnotic engine to help the player to tune into the Axoloti’s vibe.

What was surprising was how straightforward this was: find which wire is providing power, find which is the earth and then connect the rest to individual i/o pins. I say straightforward: there may have been a certain amount of swearing.

The programming ethos for the display is to connect any control signals that you can - and you can in most cases - to the individual segments. It doesn’t have to make sense: it needs to boogie.

From Oboe to Spacehorn

Anyway, this was the state of play about a year ago and I started concentrating on more esoteric matters like the idiosyncratic techniques for programming polyphony and sequencing using the Axoloti.

And then the Spacehorn arrived: as an occasional oboeist, and finding that I listen to far more jazz than rock these days, I had been considering wind controllers for a while. The oboe has a double-reed, unlike the cool single reeds like saxes, and isn’t immediately translatable to other horns because embouchure is very specific in wind instruments.

Anyway, I made the investment, I played with the packaged software - which occasionally makes a decent fist of pretending to be acoustic woodwind - but my real interest in this instrument was summed up by the two words that attracted me to the EWI USB in particular: those words are “class compliant” - the plug & play of USB MIDI.

Setting up breath control

I ran it through an old Roland Super JV, but that’s a pretty deep machine and my first attempts at understanding breath control were a little underwhelming. So I turned to the Axoloti.

The EWI attaches direct to the USB port on the back of the Axoloti and it powers the device. This is the first thing that I needed it to do. I didn’t want to be messing around with extra power leads. The Axoloti will talk to the EWI straight out of the box. Because class compliant.

Next thing was to set up breath control (CC-2) to modulate cutoff on filters and volume envelopes. It sounded the business immediately with a little fake Moog mono patch. Breath control is so much more expressive than a foot pedal or a volume knob. It’s like singing. You literally breathe life into the machine.

Finally: can I make all of that breath control make the 7 segment display boogie? Damn right I can! Set an LFO for each segment of the display and send that CC-2 data to control that LFO speed.

• Zali Krishna is a multi-instrumentalist improviser/songwriter/bricoleur and multimedia artist with fingers in many pies and his head firmly in the clouds. He plays electric sitar with drone duo Raagnagrok, and digressive guitar with psych-prog landscapists Durga, as well as recording and performing solo under many noms de guerres.