Interesting. The McCormack 0.5, & the Conrad Johnson MF-2250 were the 2 amps I was going to suggest. I'd also say--I've had a "non-A" MF-2250 for years, & I think it sounds beautiful. And I had a stock, (no-"revs") DNA 0.5 in the same system for a few days; it sounded very, very nice.
If you could pick up a stock DNA 0.5 for $500-ish, I'd grab it.
If you could pick up a stock DNA 0.5 for $500-ish, I'd grab it.