Hum from amp - should I worry?

I have a Meridian 557. IT doesn't hum unless I use XLR interconnects without using the shorter plugs into the RCA inputs. If you put your ear next tothe 557 you will hear a slight hum in the unit. Inaudible from a foot away.

Hey, thanks Tap3 & 7671 - I've been listening closely since my post went up and as you said 7671, the hum is now only audible when my ear is pressed against the face of the amp. When I first heard it, it was audible away from the amp, but it only lasted for a few minutes. Maybe there was a power service problem that morning. Who knows - the amp still plays great, but I just hope it's not a sign of something worse to come. Thanks.

Enjoy the 557. It is a great amp that has been missed by the audio industry!! When coupled to the Meridian 502 pre-amp and 508.24 cd player, it is awesome sounding.

7671 - that's the exact same component set-up I have...you are right, the 557/502/508 combo is killer. Now you've got me curious, what's your speaker/cable combo?

Electraglide FatMan on amp and Fat Boys on cd/pre-amp. MillerSound giant speakerwires(kock off of JPS superconductor 2 wires)two separate runs in bi-wire format and balanced Delta Lab silver interconnects on CD to pre-amp and pre-amp to amp.Delta lab power cords on electostatic speakers and line conditioner.