I ran my Heresy's using my Mac MC40's and later upgraded to HeathKit AS101's, basically Altec Valencias in nicer cabinets.
Anyway, I have had several tube amps on those Heathkits and NONE of them hum. The HeathKits are around 100db/meter/watt efficient so they would be very unforgiving of any hum present.
Nothing so far has surpassed the sound of those MC40's, they keep going back into the rotation although a nice Scott 222B is in the lineup at the moment.
BillWojo