@blindjim thank you for your thoughtful response about each of these amps. I have made the decision to go with the BAT because A) brand synergy, B) The Atma M-60 monos, although beautiful and detailed were slightly thin in areas, less body, or"meat on the bones" as they say. C) Less fussing around with tubes and fuses, and of course this was the S-30 so even less power there. I think both companies are great but so far I like the overall sound of BAT and I am hoping that the 55 has nice transients, open space around instruments like the M-60 but with more weight. HA, we will see .
Best, Greg
Best, Greg