Linkoping,
I know how frustrating this can be. I just had this problem when I changed preamps from an ARC to the TAD-150 by Bizzy Bee. I put a cheater on the preamp power cord and it went away. What kind of surge protection are you using. If monster, there were problems with some of the TAD-150;s . As soon as the surge protector was changed the problem went away. There are different kinds of isolation devices that you can get on audiogon. Tripp lite makes some good ones. If it is a 60HZ hum that is usually a ground loop problem. If higher pitch buzz maybe some component in your electronics is wearing out. If you have a turntable make sure that the ground is connected securely to the ground terminal on the pre. good luck!!!! Let us know how you solved the problem. May help some other people on this site.....
Eagleman
I know how frustrating this can be. I just had this problem when I changed preamps from an ARC to the TAD-150 by Bizzy Bee. I put a cheater on the preamp power cord and it went away. What kind of surge protection are you using. If monster, there were problems with some of the TAD-150;s . As soon as the surge protector was changed the problem went away. There are different kinds of isolation devices that you can get on audiogon. Tripp lite makes some good ones. If it is a 60HZ hum that is usually a ground loop problem. If higher pitch buzz maybe some component in your electronics is wearing out. If you have a turntable make sure that the ground is connected securely to the ground terminal on the pre. good luck!!!! Let us know how you solved the problem. May help some other people on this site.....
Eagleman