Tommy89G10Personally I've been looking at Schiit Jotunheim ($499+s/h) and Audio-GD NFB-28 ($708+s/h). I want a dac/amp with balanced 4 pin for headphones and xlr outputs for my speakers.
dMangoI picked up a Schiit Jotunheim AMP/DAC. I have a pair of Audeze LCD-2 Balanced on it. The combo is amazing. Getting a balanced cable isn't a night and day difference bit it is better.
Tommy89G10A friend of mine got a Chord Mojo for like $600. I have never heard anything on its scale to compare to, but it is AMAZING.
It might not be for everyone, but it is definitely worth looking at, even if it does not meet your requirements.
dMangoI have a Schiit Jotunheim w/DAC, and HD600's, and bought one of these ZY balanced cables from Amazon last October. I think it makes a great combo. The Sennheisers benefit from the balanced cable -- tighter, better defined bass, crisper highs, and improved soundstage. The ZY cable has held up well, and seems to be well made. See my notes at: http://www.tombaugh.org/good-schiit-rocky-mountain-audio-fest
dMangoThose are two great DAC/amps. However, even though the Audio-gd is $200+ more, you are getting more for your money. More expensive DAC, beefier power circuitry and filtering, more powerful (and probably better) headphone amp, better USB implementation. With the Schiit, other than the lower price, and it being more portable at half of the size and weight, the main advantage is the modularity - allowing you to potentially upgrade the DAC later on.
BradTombaugh*Disclaimer: Pure speculation below
I would the venture the electrical fuggery needed to sum a balanced signal for the SE output has more of an impact when making comparisons than the benefits one gets from a balanced output. The SE output often measures significantly worse (not just in power) than the balanced output (Jotunheim actually seems above par in this category). Hard question to definitively answer as one would need a fully SE amp from the same manufacturer with similar power specs to the balanced version from the same manufacturer... I'm not aware of any real world products that fit this description.
dMangoI got the Jotunheim + USB balanced DAC a couple of days ago and it is everything I expected. For the price it is unbeatable, so don't think twice.
ElectronicVicesAudio-gd nfb-28 (balanced) vs nfb-29 (SE) would be pretty close. They have the same power delivery circuitry. For the nfb-28, it is split across each channel at +15/-15V, and in the nfb-29, in a single higher voltage +30/-30V implementation (effectively making the nfb-28 in balanced mode as powerful and with as much gain as the nfb-29 in SE mode).