Bass Big Muff hum problem

[NeKaS]

I bought a Bass big muff on internet last week and I've received today. I immediately grab my bass and tried the pedal but unfortunately all I could hear was a really loud hum (I think this is the word). After playing with the knobs I manage to get some sort of fuzz, however the loud hum was still there. I was wondering whether if I'm doing something wrong or is just that the pedal is broken. I've attached a sound clip so you can judge. It goes clean, BBM with no bass, mids at 12 and treble maximun and finally cutting off the treble and bass all the way up.

[McSpunckle]

That can't be right. I've built pedals that did something similar (lots of noise, not very distorted sound coming through) if the power ground wasn't connected.

You shouldn't be doing anything wrong, unless your power supply is messed up. I'd think if it were a cord you'd here a pretty bad hum with it bypassed too.

Take/send it back and get a new one.