I recently purchased a USB Midi module and noticed when I plug it in i'm getting some ground noise through my output module (even if my eurorack is powered off, i'll hear when the hard drive/fan starts cranking). I've isolated the issue to just be between the USB input to the MIDI and the output module, and when I remove the output module and go direct to headphones the noise is gone.
The MIDI is 2HP Midi, and the output module is Lifeforms by Pittsburgh. Its going into a 1/4" guitar cable into an audio interface. I don't get any noise when I do not have the USB cable plugged in to the MIDI module. What can I do to remove this hum?
Andrew br> br>