Try a "cheater" plug to temporarily lift the ground. If that clears it, you have a ground loop issue. If it doesn't clear it, remove all input cables. Is the noise still there? If so, you have an amplifier issue.
Leben cs300xs electrical noise in tweeters?
Hi!, I have a Leben cs300xs amp and I like the sound, but I discovered that the amplifier produces a little "electrical" noise in the tweeters of the speakers ( philips miniwatt with 91dB) if my ears are in tweeter... This is normal?.... Another owners of the Leben with the same experience?.... Thank you!