DIY Music Machines – Mixer/Traktor contoller and 4-ch Audio Interface

Lots of progress on two parts of this project has happened in the last few months. I have a working prototype of the Traktor/mixer controller, with 3 fully operational channels and good Traktor integration as well as a USB 4ch (two stereo pairs) audio interface. They are not integrated yet but that will happen sometime after Burning Man.

Introducing Hyperion – Traktor controller/mixer module

After months of work I finally have a device I can use as a fully-functional DJ controller (still missing the audio interface). Pictured below is the prototype, showing three Hyperion modules and one Cenx4 module. The Cenx4 is currently a placeholder until I create a “master” module that integrates with the audio interface shown below.


Each channel strip gives me control of gain, EQ (3 or 4 bands with knobs to spare), simple looping, cueing, filter, fader… and I haven’t even mapped all the controls 🙂 The Cenx4 module allows switching between 3 layers:

  1. The default layer where the buttons in each strip are used to control effects/filter/etc.
  2. A browse mode that lets the user navigate Traktor’s browser, play tracks in the preview player and load tracks into the decks.
  3. A cue mode that lets the user select cue points, cue/pause, jump, etc.

More details to follow. Source code and schematics are available in the Pulsar Heavy Industries repo.

Introducing Narvi – 4ch Audio Interface module

What do we currently have?

  • 2 channels: Balanced outputs + line level outputs using TI’s “Higest Performance” PCM1792ADAC. Output stage consists of the high-performance OPA1632 op-amp.
  • 2 channels: Headphones output using TI’s PCM5102A DAC.
  • Both DACs are receiving 24 bit audio over USB, powered by an STM32F429 microcontroller.
  • USB asynchronous sample rate feedback provided by using a timer to measure MCK.
  • MIDI input, MIDI output.
  • Many supply rails created from an external +12V supply (+5V for powering modules – would be used in a non-standalone configuration), +/-15V regulated down to +/-12V for the analog output stage, +5V for the DACs, as well as +3.3V
  • Modular design: A DAC+Power supply board and a CPU board.

What’s missing?

  • Hardware: The stand-alone audio interface will have a simple character LCD + two rotatry encoders to control it. Boards have been ordered but not shipped yet.
  • Software: Need to fix a bunch of bugs, create bootloader, add LCD support.
  • Need to measure performance with an audio analyzer.
  • Need to cleanup and release code + schematics (work being done in this branch at the moment.

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