FetAmp : Simple and elegant solution to adding gain

These FetAmps were bundled with the new SM7B microphones we purchased for a studio rebuild. They do exactly what they say on the tin and give the 7B a much needed boost. For some reason though when used with our Alice Series A desk we get a very low level buzz induced to the signal chain and this affects all three FetAmps and channels in any combination. If I try them all on another mixer (D&R Airmate) the buzz disappears altogether and the gain improvement is crystal clear so I can only attribute the issue to the Alice desk itself. Luckily the Alice has a good 60dB of adjustable gain and these channel are superbly quiet so we weren't in trouble. I still need to experiment further with another Alice Series A in the second studio and probably just need to add some decoupling to the channel strip to soft this buzzing issue. After all they are classic mixers and need a bit of TLC from time to time!