30 watts? Puh-leeze....really? That's what I don't like about b-15's. Not nearly enough power for bass. Hope that's not right.
What? Do you mean that you don't subscribe to the "correct" theory of bass stage amplification that all bass amps should be only small monitors with your super-powered line array run by a tonedeaf guitar player wannabe handling all the "ting" of your frets and the "click" of the strings??? Next thing you'll say is that a bass sound should have audible low end and punch...crazy!!!
Seriously though, EL84 bass amps are very rare. Traynor made a combo, the YBA-2 Bass-Mate which had two later iterations, the "A" and "B," and that's the only one I can think of. It's a very unique tone: think AC30. For what it is, it's refreshing to see this twist on the the B15 formula. Ashdown has some big-boy tube bass amps, too. It's ironic that the Trace Elliot remains are now more "Ampeg" than Ampeg.