I got a 4-6v6 Abraxas (30W) 4 months ago and holy sh.t ! this thing is amazing. I can't stop playing it. I have one of Mark's 2x12 mahogany cabs and I play a D'pergo Limited strat-style maple/swampash guitar . The Abraxas has a full load of NOS tubes, and yeah, going NOS is worth it. Big Time The clean sounds are like none I have ever heard before - tight yet huge chime and bloom and the harmonics are sooooo rich. Play a jazz chord and you can clearly hear each note ringing like a bell. The tone is tighter/more focused than a mean street, but still has that killer Pure 64 note definition : tons of richness and detail and a liquid "goooeyness" to the notes. the clean channel loves nasty pedals and the effects loop send & return level adjustment is the icing on the cake. The Abraxas on the clean channel is simply the best amp I have ever heard for traditional blues or jazz tones. Huge dynamic range and the more you dig in, the sweeter it sounds. The lead channel is suhweet and will do a cleanish boost to a screaming lead tone. The curve switch is simply amazing....it sounds like much more is going on than simple EQ - it changes note definition and character giving you a wide variety of tones and amp responses to play with. This is definitely an amp that benefits from attention to the little details like NOS tubes, good cables and regulated power. Oh yeah, nice guitars and pickups come in handy too Mark's a great guy to deal with and he knows how to take care of his customers. I was fortunate enough to visit Mark's studio and when I heard his amps for the first time I was floored by their touch response and 3D tone. I simply had no idea guitar amps could be this awesome. Silly me, living a sheltered life... I can't find anything to complain about on this amp...not for the faint of wallet but once you play it for a while, the price will seem like a steal. For blues players that live at the edge of breakup and want huge dynamic range , the Abraxas is going to be tough to beat.