I recently bought a Blackstar HT-60 Stage Amp, and although i'm happy with the low end on the clean channel; the two drive channels really don't give me enough. I'm aware the amp isn't really worn in just yet and I know it will probably loosen up in time. (was thinking of running an oscilator on it and going out for the day)

Would anyone recommend replacing the tubes with some that would warm it up a little? Not something i've done before so would appreciate some advice.