I've been reading so many replies and reviews how the O2, Magni and Vali sound the same. After weeks of listening to all of them, (yes I have them all) they are all not exactly the same . I've been using the same music and all else in the system is the same and have only changed the amps. Started with O2, then went to Magni. Yes the Magni and O2 sound very close. The Magni does sound a tad processed and thin compared to O2 but the Magni does have more authority as it is more powerful in comparison even though they all seem to struggle reproducing the source.
Then I went to the Vali. The Vali sounds nothing like the others. It's slightly more smoother and warmer, more of a natural sound but ever so slightly, and more realistic sounding. I was enjoying it very much for weeks. Then I decided to get the Asgard 2. Why? I read so much about it I just had to try it. The Vali also seem to struggle reproducing the source which makes sense as it's less powerful.
I have to say the Asgard 2 is is not like any of the others. Why have some said there is no difference? I'm suspecting what is happening is that people are not using high resolution (or not high enough resolution) tracks or headphones to distinguish the difference OR they just don't hear the difference due to their hearing biology. As a side note: I also did an electronic spectrum hearing test to verify my hearing at different frequencies to eliminate that factor, and I passed 100%.
The Asgard 2; is in a whole other class. The Asgard 2 with the same headphones (HE-400) sound way more detailed, realistic, bassier, deeper, smoother and wider is the best way to explain it with all else in the system being the same. The Mids seem more forward and lush. The Asgard 2 does not appear to add any color to the sound, but I may say on a scale from 1-100% if I had to say how much I think it does add coloration, maybe 10-20% which is not relevant to be considered significant, it's a really tiny amount but pleasant. The gain is also contributing to the level of authority also as it does have more gain than all the others even though it's also rated at 32 ohms at 1.0W RMS.
As for noise (hiss); No hiss at any volume level either on High or Low gain either connected or not connected to a source with HE-400, so if you have higher impedance headphones there should be no worries.
As for humming; it's there, but like others have stated, it's barely noticeable to non existent and that is an exaggeration even at least for my model. My findings are this; you have to be in a dead silent room and paste your ear on the chassis right over the transformer to hear it and even then it's so tiny of a sound there is no way anyone can hear this humming unless they are intentionally to try to hear it. Even if you put your ear on top of the amp over the grill area or to the side where the transformer is located, you can't hear it still. If your ear is one inch away from the same location you just can't possibly hear it unless you are super human! Shiit has done an excellent job in resolving this issue as others have stated overall.
As for the volume knob getting warm, it's so minor I can't say it's even an issue. But here is a tip if it really bothers you or yours gets possibly hotter than you like. I have done this with all my Shiit amps but not due to heat issues but just ease of turning the volume knob. Get 3 O-rings that are a tad smaller in diameter than the volume knob and place them over the volume knob. On the Asgard 2 it makes it easier to turn the volume knob also but the added advantage is you won't feel any heat off the knob. Plus it looks nice too!
My serial is 002026 so I would hope all higher models do not have any of these issues or that they don't creep back into production. So for anyone that is thinking about the Asgard 2, YES it's worth it. You WILL hear a difference with respect to what was mentioned above about headphones, music quality rate and biology. This amp just sound like an actual amp, it sound "real" while the others mentioned sound like they're struggling to making an effort to process the sound, but the Asgard 2 seems to do it effortlessly with authority is another nice way to describe it.
I hope this helps anyone who maybe interested in the Asgard 2.