Having owned the Modi/Magni as well as the ODAC (which I also used with the Magni and SA-31), I would TOTALLY go straight for the Compass 2. The Magni/Modi was slightly treble oriented (just a hint). The ODAC is wonderful, but comparing it to the inner DAC on the Compass 2, it sounded pretty identical, and you get the 32 bit options on the Compass 2, whereas the ODAC stops at 24/96.
I love the simplicity of having everything in one package. Less clutter, and cables. Yes, you can use your own DAC with the Compass 2 if you want (like testing the ODAC with the Compass 2's amp), and it has a fixed line out (for using as a DAC only for another amp which I find unnecessary unless you wanna try tube amps) or variable line out for something like speakers that don't have their own volume control (I hooked up my cheap desktop speakers to it which don't have their own volume control). In default, it's variable, so if you want fixed, you'll have to add a jumper (as mentioned on A-GD's website.) I say that unless you plan on using another amp, I'd leave it at variable.
The Compass 2 is full of energy and clarity. I honestly think it pairs up better with the HE-400 than the SA-31 did (I could swear the mids are clearer with the Compass 2). Of course, changes are subtle, but I really love the Compass 2 so far. The Magni and O2 are very neutral amps, while the Compass 2 is neutral with a hint of musicality/warmth. I much prefer to have some warmth. Trust me.
The initial setup (on the computer) is a bit of a pain, but not too hard.
This is my 3rd Audio-GD device, and I'm a true fan of Kingwa's stuff. I don't see myself getting another main amp/dac in the future, instead probably just getting a portable one for a laptop or something (like the E17...for the 3rd time, lol).
edit: Hmm, I may have to change from ES9018 direct to using the DIR module, as I'm getting some crackles here and there. It's a very rare occurence, but it did happen. Had a feeling my PC's sound card was gonna be a piece of crap.
I specifically asked for the DIR9001 as it's more neutral than the stock DIR chip. I guess I'll change it when I come home from shipping out the SA-31.
Congratulations on your new addition, I hate "Fixing/replacing" and opening my new purchases (or maybe I am lazy).
Can Audio-gd (Kingwa), replace these items before shipping? even if it took more time to ship, I prefer it being replaced by some pro, other than myself....
Edited by turokrocks - 1/15/13 at 11:42am