Mu metal for Brio Integratdd

Good point.   I did bring it to a certified tech who gave it a clean bill of health so to speak.   I may try the mu metal as per Amazon for a sheet at about $60.  Worth a try so to speak

How did the certified tech explain the hum?

Actually I had two techs look at it and both stated the close confines of the components in the 1/2 sized chassis is the likely culprit

I remain confused. I can't imagine a well respected manufacturer releasing an amp with audible hum.  Don't know which Tekton speakers you have, but do know they are a bit more sensitive than many speakers, but hardly anything over the top in that area (like horn loaded speakers.)

I've had a number of "half size" amps (Bel Canto, VTV, Schiit) and none of them have exhibited any hum, even with my ear next to the speaker. And I've always heard nice things about Rega products.

Sounds like you either have a defective Rega or, for whatever reason, it is just a bad match for your setup.  If I were you, I'd be moving on at this point.

I did some research and there are others noting same issue with this particular Rega.    I will try the MU metal since I’m curious if it could improve the situation.   If yes then I’m good to go.   Else I may switch to a Schiit amp set up