It's just a few preamp mods away from being a bass amp, and that's only if you don't like how it sounds now. Those Philips output tubes are either Mullards or Siemens, and you could pull them and sell them for enough to buy a set of 6CA7's (same type as those EL34's more or less, but much better for bass and a lot tougher) and mod the amp to be better for bass. BTW, Traynor's are killer, but all their amps, even their bass amps, are voiced a little bright.