Portable 4sum Audio Mixer

The perfect pocket companion for your mini synths?      04/10/18

Portable 4sum Audio Mixer

SyntherJack has been in touch to tell us that, based on his synth meets and home DIY experience he has designed a simple, portable audio mixer - 4sum. He believes that it is a great companion for mini synths, like Monotrons and Volcas and also makes an excellent first audio-related DIY project.

Main features:

  • 4 mono inputs / 1 stereo (double mono) output with separated volume controls
  • very long runtime (average 100 h)
  • small factor
  • beginner friendly build


Here's the mixer being use in a Monotron Duo/Delay jam...


Pricing and Availability:
Mixer can be bought via from patch.audio online synthesizer shop as a full kit.

More information:




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