Soundsophist,
Is your judgement of the sound superiority of the BPA based on A/B comparison with the AMP2 or the output transistor? I have a couple of AMP2s and an AMP3 and have wondered from time to time about buying one of the newer higher power Proceed amps. OTOH, the AMP2 sounds clean and transparent to me and has more than enough power to drive my KEF 104/2s, so I've also wondered if I'd just be burning more energy.
db