Hey all, here's an update on Frank I's ex-Asgard (now owned by Shiaulou.)
As promised, we took it back and ran it through the full suite of instrument and listening tests. The bottom line is that the instrument tests were all well within spec: channel balance, max output, THD+N, etc. Square wave response looked fine, no ringing or anything strange like that.
But--it did sound a bit off. Our listening tech, who has listened to hundreds of Asgards, said, "Yeah, there's something odd here." So, we tore it down and took a deeper look. We only found one thing wrong with it. The thermal pads on the MOSFET regulators were installed backwards, so they were only insulating the tabs. This in itself shouldn't make the amp sound funny, but "shouldn't" and "doesn't" in audio are two different things sometimes.
We fixed the pads, and touched up a couple of solder joints that didn't look so hot (maybe due to all the shipping--you should have seen the box when it arrived, this amp has had something like 3 or 4 owners) and burned it in for a day. The result is that Shiaulou's Asgard now sounds like an Asgard should. I wish I could be more definitive as to *why* it sounds better, but there you go.
We'll see what Shiaulou says when he gets it back--that's what really matters!