I know there are plenty of threads on DRRI's and speakers. I just picked one up and I can see why. It isn't a really great sounding speaker. I got this amp used and I really don't know how old it is, it looks to have the original tubes in it. It has that Jensen speaker in it which seems to be flubby on the bottom, harsh on the top end and not much happening in the midrange. I think it sounds ugly as it breaks up, just my opinion. I can only assume this one is pretty broken in. If I replace this speaker I definitely want something less efficient, at least not louder. I also replaced the stock groove tubes (rebranded Electro Harmonix) with some Tung Sol reissues and the reverb driver tube with a JAN phillips NOS tube and that made the reverb much better. The preamp tubes are stock and I haven't had a chance to try anything else in there yet.