Hum starting between -85 to -80db

[Craig1512]

@Craig1512 I can try this either tonight or tomorrow - be mindful my 440 Pro has the CI Board.

Thank you @baddog i don’t think the CI board would have any effect on the phono stage? The only other thing I can think of here, is that it is power supply related. When listening to an LP around midnight last night, I did think that the hiss/hum/buzz was less obvious, but I had been trouble shooting this for most of the afternoon and evening, so I put it down to having spent too much time on this and going slightly mad! And surely the PS Audio power plant would clean up any noise! Mmm maybe I need to look into this one a bit more and see what PS Audio think.