This unit will not suit everyone but it's worth knowing about.
It's what I'd spend your budget on.
i'm In love with (my wife) the antelope zodiac gold. is there any major difference between zodiac+ and the zodiac gold?
edit: saw that they're over my budget.
also,i saw the 2010 tadac, it looks great,any comparison to the others dac i've mentioned?
now there's my new list:
ps perfect wave
wavelength the brick
audio gd re7
antelope zodiac or + or gold (will depend of the price.)
wyred4sound dac 2
For $400 (or less), you could get a Gamma-2 which also uses Woflson DAC but will sound much better than any iMod which is overhyped.
I'm not a big fan of the pro-audio dacs for the most part, especially the Benchmark which occurs to me as sterile and ever-strident in the upper regions. Plenty of folks seem to like it though, so you might too. I'd tend to look at more audiophile centric-choices myself (since those are the ones I've liked most), and would therefore second recommendations for Wavelength, Havana, AudioNote, and RWA. Regarding having USB as a mandatory option, I'd point at Empirical Audio's OffRamp to get you past that hurdle if you want to go with other options. Steve Nugent's stuff is excellent, and can sometimes be sourced on the used market. Of course there are much cheaper ways to get USB/SPDIF conversion, the most recent of which, like the HiFace, I have not heard. I've heard great things about the Perfect Wave and am very happy with the much less expensive, DLIII in my office system - the PW would be a compelling choice to me at $2k.
I’m dubious such a broad group of audio products can differ in sonics as vastly portrayed. Their functionality should be aligned with a common goal, preserve the original signal. To digress from this principle from the very Genesis of the signals passage would surely end in no mans land, without a hope in hell of resurrecting the authentic event. A designer who does not follow this theory is doing him/herself a great disservice, so I ask the question what intention or purpose does an abbreviation or adaption of the signal gain? Is it compensation for possible floors in the design and manufacturing?
I conclude the commentary thus far concerning the sonic qualities of various DACs should be taken heavily with a grain of salt.