LED lights in close proximity can cause some interference. I have some on my TurnTable base and I turn them off when listening to the TT. It's far enough away from my amp though.
Yes, I don't care what they say about LED lighting, replace the bulbs with halogens as they burn out. And if you have light dimmers they don't work with the cheaper LED bulbs. I just hate that eerie fraction of a second between turning the light switch off and the bulbs going dark.
But one more thing that's not a matter of opinion, it's DVD players and such...put them too near your tuner and they squawl like a hurt cat. Don't stack the DVD player etc in the same stack, move it over toward the TV equipment side. Other things like that cause the same problem.
Another thing...don't use the wall socket screw for grounding, leave all 3-prong AC plugs intact (don't cut the bottom prong off for a two-prong outlet, have those old outlets properly replaced with new 3-prong ones).
Ground your preamp to the amp and phono etc to the preamp, or ground what goes directly into the amp on the amp and what goes into other components to that.
The other possibility, and it's not so uncommon, is a simple broken cable or speaker wire, or that the RCA jacks need cleaning.
