MPA open-sourced, on sale

The complete design (PCB, bill of materials, firmware source code) for the MPA MIDI decoder has been posted under the Creative Commons Attribution-ShareAlike license. The source files can be found at the MPA support forum.

The MPA has been placed on sale at the Highly Liquid Store and will be discontinued after remaining inventory has been depleted.

The MPA (MIDI potentiometer array) is a general-purpose MIDI decoder with 8 independent 5V logic outputs and 4 independent digital potentiometer outputs.


Galanti Praeludium II console MIDI retrofit

Highly Liquid Forum user Jim U recently completed a MIDI conversion of a Galanti Praeludium II organ console for use with Hauptwerk virtual organ software. Three MIDI CPU units generate MIDI output from manuals, stops and pedals. Four MD24 units drive various LED indicators on the console. Additional project discussion can be found at The Organ Forum.




Highly Liquid user profile: Pastel Fractal

Chicago-based artist Alexander DeGraaf employs several UMR2 and MSA-T boards for his ongoing project Pastel Fractal. Alex uses MIDI control for robotics and live audience participation in addition to more traditional sequencing and synthesis functions.


Alex writes:

I have three sampling keyboards into which I have installed UMRs: two Yamaha VSS-30s and one Casio SK-8.  I use different samples on the keyboards for different compositions such as: my singing voice, a dog bark (sampled from SK-5), a TR-808 clap, a Doc Watson banjo riff, a Chet Atkins guitar riff, and some scatting sounds.

In my installation sculptures, I’ve used as many as two MSA-T MIDI Decoders to turn my MIDI note messages into voltage pulses for as many as fourteen small 24V solenoid motors. I’ve engineered these motors to reset immediately after being triggered, and I’ve connected them in various ways to percussive elements within the sculptures. In this way, I am able to MIDI-sequence robotic percussion strikes and sounds in sync with my compositions that are otherwise played by more conventional MIDI sound engines such as synthesizers, keyboards, and drum machines. The robotic percussive elements within the sculpture each provide a unique source from which sounds stimulate the inhabitant of the sculpture. I provide additional sound sources – besides robotic percussions and the main P.A. – by attaching small speakers to individual keyboards and drum machines so they may be hung around the sculpture or handed out to the inhabitants to pass and move about. Thus, inhabitants of the sculpture – also known as members of the audience – can contribute to the composition during a performance with these floating pieces of hardware by engaging buttons or keys within their reach.

More from Pastel Fractal can be found at Vimeo, Soundcloud, and Facebook.

Vintage Hammond drawbars as MIDI controller for Nord Electro 3

Highly Liquid Forum user cjfox rehoused a set of Hammond drawbars and replaced the original resistor wires with slide pots. Then he used a MIDI CPU to convert the drawbars into a MIDI controller for use with his Nord Electro 3.  The MIDI CPU configuration is posted in the project’s forum thread.