I will post a quick subjective review of the xduoo xp-1:
Yesterday, I had some time before my valentines day date so I headed down to Jaben Singapore to audition the xduoo xp-1 as they have a demo unit. I was quite excited to learn about the XP-1 as I had long since given up hope that I'll be able to bypass the dac and amp units in my phone and ipod (what i use as my portable music players) without paying an arm and leg for it.
Form factor: The XP-1 has a pretty small footprint, and is very slim, so when paired to my S3, it doesn't add a whole lot bulk, the slimness being the main factor. The case is very slim, and I was a little disappointed because I thought the dotted surface of the XP-1 is ACTUALLY dotted and raised, but it's just a printing. On the other hand, an actual dotted surface may be more scratch-inducing on whatever you place on it so I can't fault that design.
Sound: It paired pretty well with my FXZ200 and although it couldn't hold a candle to my O2 amp, it came pretty close. The bass boost switch works quite well, adding a small but noticeable amount of bass that doesn't muddied up the earphone's entire sound signature. I won't go into much more details until I have more time to play with it. The pairing with the FXT90 was much worse, the reason being that FXT90, just paired to a 100% neutral set up (ODAC+O2), has just the right amount of warmth. When paired with any setup that is even slightly warm, the final sound will become too warm to my liking. Hence, I will conclude that the XP-1 is at least slightly warm and not 100% neutral, but again, I didn't spend alot of time with it.
Functions: This is where the XP-1 shines. For its price, it has ALOT of functions; USB in from android phones (I assume this to mean bypassing the phone's internal dac and amp, so someone corrects me if i'm wrong), AUX in and out, bass boost, and phone charging. The battery is slated to last for 10 to 12 hours on normal use, no idea how long it will use if it acts like a phone charger. It should also comes with a lot of cables, the most important to me being the short right-angled OTG cable, as it reduced the footprint dealt by the connection. There is a quirk in which sometimes, your phone won't recognize the XP-1 and will play the music through its speakers instead of through the device. All you have to do is restart your phone. I will have to investigate what sets this quirk off as yesterday, after getting the XP-1 to work once, I have to restart my phone for a 2nd time. Oh and make sure your android version is above 3.0.
Value: It (should) cost me S$320 (US$259). I say should because I bought it at a 10% promo discount, and instead of receiving the XP-1, I got the XD-1 instead. I believe the XP-1 and the XD-1 are the same price, but I can't confirm that for now. I'll have to make a trip down to Jaben to exchange it.
Even though the amp is slightly warm, and does not pair well with the FXT90, I still bought it (or at least I wanted to buy it ><) because it offered alot of additional functions in a small portable package, at a relatively low price. Plus it pairs pretty well with my FXZ200, which is what I mainly use nowadays. If you're sitting on the fence, and deciding to get the XP-1, I will advise you to get it, especially if you have an android phone. Hope this is somewhat useful to those who are thinking of getting it.