How much hum is normal from a new tube amp

I have a KT150 amp. There is a very faint hum from the amp on start-up, that goes away once it's fully on and warmed up for a few minutes (it has a 2 stage power up process). Otherwise it is really quiet. 

I sometimes hear a very faint hum/clicking sound from one speaker but I have to get very close to hear it and I know that is from the modem.

Which amp do you have? If I can ask.

Of course - details in my profile but it’s a Rogers High Fidelity EHF-200 MK2. I’ve had it just over 2 months. Very happy. It replaced a Raven Audio Osprey which was fantastic but I wanted more power to drive my Harbeth’s.

Correction, sorry.

There is a very faint hum from the amp on start-up, that goes away once it’s fully on and warmed up for a few minutes

The faint hum on start up is from the speakers - fades after 10-15 seconds - the amp is dead quiet.