You probably have a ground loop. Assuming that is correct you need to identify the source. I suggest you not only disconnect but unplug everything connected to your amp (except the speakers of course). Turn the amp on. Any buzz? I suspect not, but if you do its likely something is wrong internally.
Assuming there is no buzz, plug in a component (do not connect it with IC's). No buzz? If not the turn off amp and connect IC's. No buzz. Repeat process with other components until the buzz appears.
When the buzz appears attach a cheater plug to the PC on that component replug in in and see if the buzz goes away. If it does you are in hog heaven. It is not unsafe to operate your system so long as the amp is fully grounded.
If nothing eliminates the hum and the hum is really low in volume, i.e. heard only with your ear at the speaker grill, you might have just heard the amps noise threshold. This is not uncommon with very efficient speakers and its not a big deal.
Assuming there is no buzz, plug in a component (do not connect it with IC's). No buzz? If not the turn off amp and connect IC's. No buzz. Repeat process with other components until the buzz appears.
When the buzz appears attach a cheater plug to the PC on that component replug in in and see if the buzz goes away. If it does you are in hog heaven. It is not unsafe to operate your system so long as the amp is fully grounded.
If nothing eliminates the hum and the hum is really low in volume, i.e. heard only with your ear at the speaker grill, you might have just heard the amps noise threshold. This is not uncommon with very efficient speakers and its not a big deal.