Flipped that little bias switch and loaded it with 6L6's. Why didn't I do this sooner? Much nicer cleans, smoother gain, tighter lows, overall just more articulate and refined. Really noticeable on the Blue channel especially. I know the RA-100 is supposed to a "British" voiced amp, but I don't think I'll be going back to the stock EL-34's in this amp. I'm an EL-34 fan, but this amp just sounds SO much better with 6L6's. I really liked the RA before, now....I love it.