Buzz/Hum from Cary SLI-80


When I turn on my Cary, a electronic hum is immediately audible. It does not increase in volume when I increase the volume control. It is not loud, but distinct. When I turn on the CD player, the hum remains. When I play a CThe hum is present in either Triode or UL mode. The Cary is plugged into a PS Audio UPC 200, which is plugged into silver outlet in wall. This is not a big problem, but shouldn't it be dead silent when I turn on the Cary? Could it be the tubes? Any suggestions welcome. Thanks
paulg1
Thanks for all the feedback. Will call Cary. By the by, the hum is from both speakers. Will also try a 3-prong to 2-prong plug from Cary into PS Audio. If that doesn't do it, I will try the 3-prong to 2-prong from PS Audio into wall outlet. I'm guess you mean one or the other, Ianman. Am sure I will sort it out. Thanks again.
I have a SLI-80 and its dead quiet. To clarify, is the hum coming from the speakers or from the Cary itself? If through the speakers, does the hum come through both speakers or just one? If its just from one side it could be a bad tube. To test you could swap the tubes from one side to the other to see if the hum changes sides. If so, then swap out one tube at a time on the side with the hum until it disappears.

Since the hum is immediate upon firing up the amp, it doesn't really sound like a tube to me, but you may want to try the above just to start ruling things out. As recommended, give Cary a call - they have great customer service in my experience.
cheater plugs can be a fire hazard.goolge jensen transformer "ground loop isolator" ...worked for me
Best thing to do first to be sure it is the Cary is to disconnect all components from it and plug it into the wall (if you have done this already my apologies). Is the hum still there? If yes then it is the Cary, if no, something further up the chain is causing it. Add one component at a time starting with the PS Audio until the hum appears. Cheater plugs are great for diagnosing the problem. You'll read all sorts of stuff here about the positives and negatives of their use on a permanent basis. I don't like them as a rule but sometimes you may just have to live with them, or get a balanced power conditioner.
Sounds like a ground loop to me. Try a 3 prong to 2 prong adapter on the AC cord. Also called a cheater plug. You can get them almost anywhere. Radio Shack, Home depot, the grocery store...
Should be dead quiet. Make sure transformers are not loose. But be careful to discharge power capacitors before opening the unit, as the voltages are dangerous. Also, call Cary for technical assistance. Good luck.
I used to own an SLI-80 and it was silent. Is there a cable tv coaxial cable nearby causing the hum?