Hi, I have a C2 that works well except it has a 50hz earth hum through the output- headphone and main out- it's set level, i.e. doesn't increase/decrease with the volume control. I've disconnected all connections except mains power obviously and it's still there. Checked for dry joints etc all over the boards and re-soldered some of the RCA connections and I've re-capped it, still hums. The balance control was knackered of course when I got it so I did the simple jumper by-pass. It stops humming if I turn off the output using the front switch. I've seen some C2s have a capacitor on the rear panel output RCAs, mine doesn't have this... Any ideas appreciated!