I can record sound from my microphone, but I get an loud electric hum at around 20% of the max level. This is no matter what software I use to record.
How can I get rid of that noise?
Soundcard: Analog Devices AD1984A
The only dials in alsamixer that change recording levels are Capture, Digital and Internal (which is hardlinked to another Internal). They all boost volume of both audio and noise.
The best config so far is: Capture 65, Digital 55, Internal 0 - and unplugging power supply(!) and head phones(!).