SallyB
Well-known member
I have an amp that when placed on an inner shelf of a wooden rack it audibly hummed, the hum seemingly being amplified by the partially enclosed wooden chamber within which it sat. When the amp was sat on top of the rack there was no audible hum. Would also agree that when the hum is not audible at the listening position, you have the option of deciding to live with it if further investigation is not an option for whatever reason.