Hi,

Here's a slightly weird one.

Under certain circumstances (see below) I get what seems like a ground loop, with a loud hum (well, a few db's). It's rather high pitched. Perhaps 100 Hz. Possibly 200 Hz or not even related to the AC frequency (50 Hz in Sweden). The hum is present at both analog XLR inputs, but not the Inst input.

Anyway, it completely goes away if I disconnect the extension cable and connect the breakout cable directly to the BabyFace. This is the short extension cable that comes with the interface, not the 3 m one.

Question is: could this be down to a faulty extension cable?

The hum occurs under the following conditions (all must be met):
1) Breakout cable connected to the BabyFace via the extension cable
2) Dave Smith Mopho Key switched on (doesn't have to have audio or MIDI or USB connected anywhere)
3) Roland TD-12 drum sound module switched on (only used for triggering via MIDI, no audio I/O connected) and
4) MIDI cable connected from the TD-12's MIDI Out to the breakout cable's MIDI In

I've tried different MIDI cables. The hum occurs even if nothing (except MIDI In) is connected to the breakout cable.

Anyone experienced anything similar? Any tips?

Regards
/Jonas