Glim: Got your message.... Can think of two possible sources: Ground loop Incorrect connection polarity at wall plates. For testing purposes "float" the ground in your front end components to see if the hum disappears. If it does you have a ground loop problem connections for both front end and amp should be at the same potential. (Check safety on local code) If above doesn't show improvement check that polarity connections are OK, i.e. that the lowest potential is obtained at the components chassis. . Suggest to try a cheater plug for this if you reverse connection polarity and noise is gone that's the source keep in mind that you need to keep ground connection though for this test or mixed results between reverse polarity influences and ground loops will be obtained (REMEMBER SAFETY FIRST KNOW WHAT YOU ARE DOING OR HIRE SOMEONE THAT DOES). If you have a power conditioner where you have hooked all your front ends by lifting ground for testing could also provide the answer. (Cheater plug) If capacity allows and for testing purposes you can plug the amp to the power line conditioner and see what it does for you. Don't over power the PLC but try to see if noise lowers without major power demands from amp- Need more details to help out. Could you be more specific on the connections? Amp to wall dedicated wall outlet, and front components to power line conditioner? Regards
