I've got a Blackstar HT-20. On it's own it maxes out in the hard rock range. But with an OD pedal it'll get to 80s thrash, which is about the level I want. The only problem is, with a pedal there's a lot of noise. Even if I turn the volume on the guitar all the way off, there's hiss. Do I need a noise gate? I've tried three different OD pedals, all of them have this problem. If I don't use a pedal the amp is almost completely silent.
Yeah, you could use a noisegate. Boss NS-2 is a basic place to start, but most swear by the ISP Decimator.
how do you have the pedal set?