I have a Geek Out V2 Signature Edition and I used it with my JH 13 Pro FP (Norne Therium balanced TRRS cable).
It was good but the sound didn't have enough body and I thought to myself, if this is as good as it gets, I think I am going to swear off mobile setups completely. It couldn't hold a candle to my HD800/Ether/HE-1000 setups. Wasn't even close. Didn't offer anything.
Then I had a Norne TRRS to dual 3 pin XLR Therium interconnect built and used the GO V2 SE as a DAC for my Cavalli Liquid Carbon.
I then had yet another Therium interconnect created to convert RSA kobiconn to TRRS.
THIS setup sounded FANTASTIC.
It made me wonder about my upcoming Wave XD. Would I like the sound straight out of headphone out? Or would I prefer it with an amp? I started wondering about potential stacks and I was thinking that the Cypher Labs Duet seemed like something that would work for me. The heft might become a bit much but sound wise, unless the Wave XD is going to sound much better than the GO V2 SE (it might, being dual mono and all) I might consider a Duet as a potential pairing. Thoughts?
PS: I didn't read through the 230+ pages before posting this so my apologies if someone had already brought up this topic.
I have a similar experience...use the Geek Out Signature Edition V1, which isn't balanced. Didn't particularly do amazingly well with my various headphones (HEK, HE-560, acs Encore, many others), and I always hated the volume/PC issues (to this day, haven't figured out the settings that allow me to get sound out of the rest of the PC, only get sound out of JRiver into the GO, with a Regen in between), so, as the v1 is single ended, I started using it line out into my MicroZOTL2, mostly for the volume control, to avoid the default full volume blasts I was getting directly out of the GO periodically (I also have a Liquid Carbon, like the ZOTL better, but that's a different can of worms...). Well, using GO SE v1 as just a dac was a major improvement, the sound of the GO through the ZOTL into the above headphones, or the Omni, is much better, very satisfying indeed. But, it seems logical it should be so...parts are upgraded in a more expensive amp (the Signatures, while more that the regular edition, are still at the lower end of high end audio gear), there is more room to separate components that can degrade sound when too close, more power, etc. The cigarette lighter sized usb amp/dac is basically an all in one for convenience, and has to involve design compromises, especially in power, I'd think. It's easier to carry around than a stack of stuff. But, I don't think LH Labs would tell you it's supposed to be the equivalent of, say, the Vi Dac, or the fully tricked out Pulse (and, while those contain headphone amps as well, I'm sure LH Labs would tell you the separate headphone amps are a step up from the all in one unit, and the headphone amp included is for convenience, but can be bettered. Logically, the transformer would be a limiting factor in shrunk gear, no?). So, as with most things audio, you pays yer money, you makes yer choices. Not that it is impossible to make an integrated amp/dac that sounds good. While I didn't get a chance to compare it to other gear, I did get a listen to the Macintosh MHA-100 in Stereo Exchange in Manhattan, and it sounded great with the HEK. But, it is $4500, and definitely NOT transportable...
Hoping the Wave will do better as an amp as well, there is more isolation planned according to Larry, but it's a wait and see situation, still not likely to be able to make a portable, 1 piece unit that sounds as good in the amp section as a ZOTL or a Liquid Gold.
My $0.02