Gamut D200 Mrk II hum/buzz issue

Hello all, quick question to those with these types of amps (mrkII or III...heck or even mrk I for that matter)

Does your amp make a slight bzzz when no sources are connected/on/muted? I have gone through every check and I know for sure it is not:
1 - grounding issue
2 - pre issue
3 - cable issue
4 - power issue
5 - underpants gnomes issue...(dont ask)

I dont have super sensitive speakers either...only acoustic zen adagios (88 db)...maggies MMG (86 db i think)...JBL 4312C monitors (91 db) and my theil 2.4 (88-89 db). I hear this noise on the Zens and the JBLs and the Theils..but not the maggies (I think that the planar design helps possibly mask the noise..?) Anyway...I got to the point where I had absolutely NOTHING connected to the amps except the speakers...and still could hear the noise. The buzz/hum DOES NOT get louder when the volume is turned up. Does anyone else have this issue with their d200's? I have cheaper equipment that is dead silent...even tube...any help would be appreciated.

Thanks

Spiro