Acceptable level of hum at max volume?

so i am noticing a faint hum when i set my amp to full volume. not sure if it's been there all along but i was tinkering around and noticed it. here is my setup: rega p3-24 w/ttpsu and herbie mat into jolida jd 9 into decware mini torii. if i switch the mini torii to the second input via the switch i get no hum, but when i switch back to the phono i can hear it. mind you this is at FULL VOLUME. my question is, is there an acceptable level of hum at these outrageous volumes. it's not present in the music at normal or even loud listening levels it's just something i noticed while dickering around. i've tried all the usual solutions to eliminating hum like cheater plugs and moving components and swapping cables. i even have a line conditioner. what say you enthusiasts?
Yes, some hum may be present, even with the finest systems, when the volume is completely ramped up.

You could choose to further investigate and locate the source of the hum and solutions could include running a dedicated circuit, the purchase of a power regenerator, or simply separating your signal cables from your power cords (and if they must cross make sure it is at a 90-degree angle). Sure, component distance, shielded cables, etc. should always be considered but, in my experience, the hum is always power related.

I would venture to say that acceptable hum would be that you have to put your ear next to the speaker to hear it. If the hum is audible from the listening position then that seems like a bit too much in my opinion - even if you will never play music at max volume.

Hope that helps.

Burt - Seattle Hi-Fi
My system is dead quiet, but have had hum from a bad tube. I find any level of hum to be unacceptable.