I've had my Super 17 for almost two years now, gigging, recording, playing at home. For most of that time I've used the stock complement of preamp and power tubes, EH 12AX7s and EH EL84s. Recently I replaced V1 and the PI with GE 12AX7WAs, and today received a pair of GE 6BQ5/EL84s from Mike at KCA that I just put through their paces with Strat and LP. I'm really liking the sound of this setup, smooth, robust, and sparkly. In particular, the overdrive of the GEs seems a bit beefier and a little more detailed, while cleans have a little more thump. Now I'm curious to know what my fellow Goodsell owners have tried and what your results have been. So chime in!