Transformer Hum

I use a PS Audio Humbuster and this works well on my tube gear. It really quiets down those transformers.

Newbee may be correct, but his "solution" will not work in every case; in my personal experience I exhausted all the usual suspects (cable routing, cheater plugs, changing out tubes, swapping cables, both IC and power, even turning the amp around to see if positioning was the cause) and as a last ditch hopeful solution bought the PS unit. This did not remove the all the hum heard through the speakers, but a good part of it, but it certainly quieted the trannies tremendously.