I recorded the soundcloud snippet internally with the 6 track recorder (there i noticed that the noise is slightly changing when recording). Atm i’m going from the 301 directly to a intellijel headphones out, with normal amplication i can hear the noise very clearly coming from one channel, maybe in the mix it gets drowned, but often i set up 4x poly units, so the noise appears x4…no good 
@hyena
…well…that’s brave 
There’s a 301, ansible+grid, just friends, and two 1u intellijel modules in my minicase, should consume ca 1.3 A, so no problem on that front. Can you tell me which brick exactly you are using?