Hey all -- I have a project I'm working on that involves a
raspberry pi, a , and a small electret capsule ()
powered from that interface via PiP.
Everything works, but there is 60Hz mains hum.
I believe the the audio interface is providing a stereo 1/8"
jack, but it mixes to mono internally - the computer is only
provided a mono capture by the audio interface. (If I use a
different set of stereo PiP mics that I made which are wired to a
stereo plug, there is no hum, and both capsules hear audio in the
result, but the overall signal is weak.)
The mic capsule is wired to a stereo plug (using shielded lav
cable), but the signal only goes to one channel of that plug, so I
presume the disconnected channel is just feeding in hum, is mixed
with the signal in the interface, and that explains the hum in the
result.
Does my diagnosis sound correct? If so, what would you recommend?
Should I just wire the signal from the mic to both the tip and
sleeve of the plug, or will that mess up the interaction with the
capsule somehow? Or would it be smarter to get a mono plug?
Thanks!
-Casey
