Hum Issue

[TheSapeur]

When plugged into my computer USB hub , there is a hum over the speakers. This is not present when powered from a USB charger. Also, I have the same issue when my CR78 is plugged into the analog output mini stereo Jack of the Midronome. This does not occur when it is connected via midi and a future retro Swynx synchroniser box. How can this be explained, please?

[Simon]

Yes this fit perfectly the description of this well-known issue.
Unfortunately it's a hardware issue, caused when you have a ground loop in your setup.

There are many workarounds and solution - see the linked post

Simon

[TheSapeur]

Thank you , Simon. This is an excellent product - thank you for creating it. Bruno