On the Bryston if you don't have it set to balanced you don't get any sound even if you hook it up right otherwise. On the Mjolnir you do.

Not yet. Still working on the amps.

This is such a strange comparison, and it's leaving me unable to articulate my thoughts. They sound very much different, but both sound excellent. I can tell right away when I change, but after a few tracks the differences fade and I just end up enjoying the music. The Bryston has a clear edge in detail and seems to improve on every other aspect of the Mjolnir in a minor way. The Mjolnir doesn't have any technical wins, but is slightly easier with poorer recordings. It's got a sharp smoothness to it, if that makes any sense. The best way I can describe these amps is comparing them to hand weapons. The Mjolnir is the sleek smooth entirely ergonomic assassin blade hidden in the folds of a leather suit. Deadly, but concealable without risk to the operator. The Bryston is a fine broadsword that is too large to do anything but strap it to your back and is at times unwieldy. Being out in the open it shows you everything. It relies on brute force but can still cut just as clean as the dagger.

Despite my decision that the Bryston is the superior performer, I can't come right down to it and say it's better than the Mjolnir. I would say in most cases a tube amp user would prefer the Mjolnir, and a solid state user would prefer the Bryston. In my case, I went from 3 tube amps in a row to the Bryston and prefer it. I would call these 2 amps mostly equal, just different flavors. There is a distinct quality difference between them, but I think the flavor difference is significantly more important in someone's preference of these 2 amps.

Every time I plug in the Bryston I think, this is just better, more detail, more real, what was I thinking trying anything else. Then I plug in the Mjolnir and think it sounds great as well and begin to doubt my choice in the Bryston.

If price is no object I would recommend the Bryston, if money is tight, go Mjolnir. They are close enough in performance that you really can't go wrong. I still can't make up my mind which one I want to keep. Luckily I have another week and a half to think about it.

Gungnir arrived today and it has surpassed my measured expectations. Only have it connected to the Mjolnir single ended via rca but it is a clear improvement over the Bifrost in every aspect.

There's more weight and extension in the low end, smoother mid to treble rendition, more "plankton" as purrin would say, and better separation of instruments and more precise imaging. It has really elevated the HD800 and makes it clear the Bifrost was a significant bottleneck in my chain.

Balanced interconnects will complete my setup but I think I'll be done with headfi after that. Now, speakers.

Nice -- glad you're liking your new setup.

I've been smitten with my Gungnir as well. I've written elsewhere that the Gungnir --> S7 reminds me of a baby version of Purrin's PWD --> BA combo with the HD800. It probably doesn't beat it in technicalities, but shares a lot of the same qualities I remember being so enticed with at the Bay Area meet. It's doing all the major things right, in my book.

Make sure you run the Mjolnir in for at least 100 hours. Basically don't turn it off for a few days. Still, I feel you may prefer the BHA-1 with the HD800s.