I bought a C9 and noticed a slight hum in my pedal board. I isolated it down to the power supply – the C9 does not do well with the 9VDC 200mA supply. It is fine with the OEM 9.6VDC separate supply though. *sigh* I have to now figure out a way to route that huge wall wart in my pedal board…..

Love the pedal – hate the hassle of the the power supply.