V1 Vivid Technologies
I managed to get my hands on one of these, I must say it is excellent. Really nice warm sound but packs of detail. Has anyone else any experience of these please and what headphones have you pitched with them? 
Compared to a FiiO E10 it is far superior, in my opinion. I've not experienced the others you mentioned. I'm not sure what the chip is mind. I paid just over £50 with dollar conversion. Using K450s which I love even though they're supposed to be portable (I can't as yet find a full size to compare to them. I'm quite interested in the Tiesto K67 to be honest, sorry idc!).
"Far superior" to the E10 sound pretty epic for £50. Not that I've heard the E10, but some say its better than the E17 for pure USB audio quality. Any down-sides to it? I think it doesn't support HD audio but that wouldn't bug me much. Let us know if you test it with something else.
I suppose it's only 16-bit and 48 kHz if 96 or 192 is your bag. However, it hasn't put me off and can't say I've noticed, I've just been really enjoying the music as one should. I will report in when tested with other kit. The search for full size headphones continues with equal or improved SQ over the K450s....... 
That one was quite common on Head-fi back in the day if I remember correctly. Is this the one with the PCM2704 chip, that can be powered by USB, batteries or the mains? I don't think I ever heard of any Euro resellers for Vivid so I don't think it was too popular here.
Do you know how it compares with anything similar like Fiio, iBasso or Audinst DACs etc.? How much did you pay for it BTW?
PC>JRiver> DAC/amps: Fiio, Audinst, Yulong, Arcam, Fostex, Audiolab, Schiit, Oppo, Ifi ●
Headphones: D7000, Q701, M80, M100, DT770, DT880, HP100, HP200, Mad Dog, HD650 ●