Ok, I have read old threads about the B2R and the SVT3Pro. I have played both and I like both of them equally. Only problem is where I am testing them(small cab filled room), I can't really tell much difference in power and unless I spend a couple of hours tweeking the knobs, just a little bit of sound difference. So, I can get the demo SVT3 for 700 or the B2R for 500. I am playing thru the Portabass 2x12 cab. Any clues as to the reliability of either, and just how much maintenance is required with a tube preamp?(only owned ss amps before). I am all about reliability and I can get a good sound out of either. Any input? Another canoworms eh?