Effortlessly really. It makes me realize that things like the mjolnir aren't capable of doing the entire job for the HE-6; there's a lack of dynamics and low end extension. The McIntosh is also more detailed across the spectrum, the bass is visceral and so much more textured, mids aren't hollow or have any hint of artificiality like the BHA-1 sometimes has and anything past 2khz on the HE-6 is less grainy on the McIntosh vs the mjolnir especially.
Another big plus is sounstaging and image depth. The BHA-1 is very open sounding, noticeably more so than the mjolnir. The Mc225 is even more grandiose, and the image depth is dramatically deeper and more extended. Separation is crazy really, it's hard to believe I'm wearing headphones with most well recorded/ high res tracks.
The resolution is astonishing for such an old piece of kit/ tube amp. It's been well maintained for the last 50 years, and all solders are nice/redone, caps changed, transformer upgraded and a few more tweaks. The amp beats out all Woo's I've tried (up to WA-5"LE"), Super7, Zana Deux, Stratus and a few others.
It's hard to fault; the only disadvantage is that it's not going to work with many headphones; it's not meant for that. 300 ohms minimum (HD800's), and you better be careful when setting it up/ plugging headphones in last with volume at 0.
Also, to give you an idea; the footprint is smaller than the mjolnir, but it weighs 47 lbs vs 12 lbs for the mjolnir!
It's a much better amp in all regards, and that's saying a lot because the mjolnir and BHA-1 are fantastic amps. They're not for the HE-6 as much as the HD800 or LCD phones especially.