I have a 1971 Twin Reverb, and it sounds pretty with the Eminence Tonkers I put in it. The only thing is the bass could be a little tighter. Can adjusting the bias either a little hotter or a little colder tighten up the bass any? I'm also thinking about yanking the two outside power tubes to knock the power down some. I know that would make a mis-match in impedence with both speakers hooked up, but is it safe to run it like that for a while?