ECHO Development System 2019 - 2021

ECHO Development System

Echo was our first project to use the Teensy 3.5 32-bit processor.

Essentially, I wanted a simple development system that could form the basis of any number of products, be it a synth, a drum machine, a sequencer or anything else we could dream up. Hence, the front panel design is rather minimal. Just six potentiometers, eight push buttons, five encoders and a display. Like I said, minimal.

We used Echo to develop the following:

  • Echo - a basic monophonic synthesiser that worked well. Sound-wise, it used the standard Teensy audio library and sounded quite good (until you turned on the library reverb).
  • iDrum - a four-voice Midi drum machine, the voice design was a mix of virtual analogue synthesised drums and samples, with filters, effects and panning for added colour. We got that one right. The final version let you load samples from an SD card so it was a very useful tool. I still remember the general feeling of euphoria when I loaded in a small collection of Linn Drum samples and.. yeah... that...
  • KP-01 was a Karplus-Strong synthesiser that sounded promising but ultimately didn’t really deliver. One to work on in the future, perhaps.
  • Swarm was a monophonic SuperSaw synth with sawtooth and square wave sound sources, LFO modulation and a few other tricks. This was a real high point. Instant trance. The algorithms were immediately added to Plasma’s tool kit.
  • Fader16 Control surface / DAW Interface - USB Midi interface with 16 faders, pots, switches and encoders, all user-configurable. This became one of our standard in-house development tools.
  • nLiten - eight track, 16-step sequencer, very much influenced by the Arp Sequencer
  • Pro-DGI - Eurorack monosynth, currently in development
  • Smart LFO - currently in development
  • Smart ADSR - currently in development
  • uSeq - tiny step sequencer. No longer in development...
  • Delta was an emulation of the Korg Delta String Ensemble / Synthesiser. Will be available as a downloadable for Plasma and Zyra.
  • DrumLinn - an emulation of the Linn Drum. Will be available as a downloadable for Zyra.

So, why didn’t we launch any Echo-based products? COVID, that’s why, coupled to the worldwide shortage of microprocessors. Sourcing the processors at the heart of the Teensy 3.5 and the 3.6 became a nightmare. Those distributors still carrying limited stock started demanding silly money and the project ceased to be economically viable.

We built five prototype Echo machines. They’ve all been given a home. I kept three because they were so useful.

The good news is that the code we developed for Echo will run very happily (and a lot faster) on the Teensy 4.1 so... This led to the development of our Mozart board. More on that later...