Intermediate RB1080 hum

[cfrahme52]

Lately my RB1080 seems to be producing an audible hum from within the unit.
The buzz can be noticed from a couple of feet away and is not amplified through the speakers. Appears to come from the left side of the chassis. Noticed it yesterday and after a moment it silenced itself with no intervention on my part. As far as I can tell, the amp is working normally. Is a component failing? Anyone out there ever experience this?

[madmac]

My Rotel amp hums on occasion as does my Marantz CD player but it's not bothersome. So long as the unit works and the hum does not bother you and it works, I would not sweat it. You could always try verifying that the power socket is grounded and/or all your wiring is ok.

[srb]

Often times torroid transformers will hum or buzz if there is some DC on the AC input, but I have also seen (heard) them vibrate a bit even if there isn't.

Although the RB-1080 transformer is in the center of the chassis, the vibration may be coming from its left side. I have cured a few vibrating transformers by loosening the center nut and rotating a degree or two and re-tightening. You will only have a small amount of possible rotation due to the length of the wires, but often only that small amount is needed to effect a mechanical change between the transformer and chassis.

Steve

[Dmantis]

Check your house ground or have an electrican do so. Do you use a high quality power conditioner/ Voltage stabilizer? If not I suggest checking out Panamax. The worse thing to do to a system is not have a solid back bone.

http://www.panamax.com/Products/A-V-Components/M5400-PM.php

[Rotel4Life]

I say 99% chance is transformer. My DVD xformer buzzes loudly. Tried rotating/loosen clamp down nut and retighten but didn't help. Something changed for the worse, right? Not sure if transformer failing or maybe some other (less beefy)component like a cap that may effect xformer... Checking house couldn't hurt but I wouldn't spend anything on it- likely no effect. You could try plugging into different circuits (outlet on different breaker) and/or plug in at someone else's house and see if any different. I doubt it. I wouldn't spend money until after trying it anyway.

[cfrahme52]

Thanks...

...for the thoughtful replies. I have the amp plugged directly into a wall receptacle. Just checked the power and it reads 119 AC volts. The outlet is correctly wired and along with the RB1080 my left Martin Logan Aeon i is sharing the bottom socket. My preamp, cd player and turntable are plugged ito a Tripp-lite heavy duty power strip/surge protector. This is routed to a different outlet, shared by the right ML speaker. Unfortunately all family room outlet circuits are wired to one breaker.