I prefer a sound signature that leans on the warm side which is highly detailed/articulate, clean sounding, has a nice texture, full-bodied, fast-paced, excellent instrument separation, large soundstage, and, can be a little smooth but not muffled or soft/textureless sounding. The problem is, it's hard to lay down $80-$100 on a DAC without getting even a hint of what it might sound like. I use my AD700Xs as my main PC headphones, but I want something that's going to pair well with a variety of other headphones as well.
My main options are:
AudioQuest DragonFly Black v1.5
Creative Sound Blaster Omni Surround 5.1
Creative Sound BlasterX G5 (seems like the ultimate DAC/amp, but heard some negative things about driver support and units failing)
Focusrite Scarlett Solo (not a dac per se, so not sure if good for simple headphone plug and play, maybe a bit of a stretch for what I'm looking to use it for)
Asus Xonar U7 (seems to have all the bells and whistles like the G5, but not sure about this one, because, I've read some negative reviews of this unit dying within months)
I would actually like to get a sound signature close to that of a SCPH-1001 model PlayStation, which is highly regarded as a one of the best CD players of its time with its Asahi Kasei AK4309AVM DAC. Maybe it's a little overrated for modern day usage, but I like it for what it supposedly is/does.