From your original post on the pictures i guess they were smart enough to make the modi chassis small enough so it doesnt cover the heat vents on the asgard 2 right? no problems stacking the modi on top of the asgard 2 and using the RCA PYST cables?
What kind of sources are people using that they need coax/optical? TV? record players?
I breezed through the thread but can you explain the quality difference between let's say 80% max comp volume and 20% on your amp vs 20% comp volume and 80% on your amp? Which is better, why and what happens that its better?
Anyone know if the asgard 2 will stay at 250 when the vali comes in at 120? If tubes are all the rage im surprised that the hybrid vali comes in at half the price of the asgard 2....
Yes, you could comfortably put the Modi on the far left side of the A2 without covering the vents. I wouldn't expect the heat from the A2 to be a problem, but personally I've got the A2 on a stand and the Modi below it just to make sure. I'd recommend shooting Schiit an email before leaving the A2 on for hours with the Modi on top if it just to make sure.
Other inputs...well, a lot of people here feel that those are "better quality" than USB (although personally I think Schiit's USB is quite good). Most computers and at least a reasonable number of laptops have optical. Also, yes, as you guessed, dedicated source components like CD players (not vinyl though since it's already analog).
The easiest way to get the best quality is 100% computer volume and just use the amp's volume control. However, if you run your DAC at a higher bit rate than your files (for example, Modi set to 24 bit and you're playing 16 bit FLACs) then you actually have 8 bits of digital volume before you start losing any actual data (if both are at 16 bit then turning it down digitally is actually discarding audio data). Whether that's a good idea is almost entirely dependent on the noise floor of your DAC, so it's not the easiest thing to issue a blanket statement about. In general though, the A2's volume control is good enough that you should just leave digital volume at 100% and use the A2's volume.
Going off of all the pricing history we have on Schiit, the A2 is almost guaranteed to stay at the same price. A2 is significantly more versatile than the Vali; it can drive many more types of headphones (IEMs, etc), has a much lower noise floor, puts out more power, and can be used as a pre-amp.
With that said, I definitely intend to try the Vali at some point since it seems like it'd be a great fit for my HD600s.