Okay, so I'm quoting shotgunshane's post, and not snipping, because his impression lines up with mine almost 100%.
I found the O2/ODAC to be more detailed, with better resolution, clarity, transparency, and wider soundstage thanks to the O2 (though not necessarily a good thing in a lot of the cases). However, I found the GDX to be much more lush in the mids, especially female vocals. One thing to note is, ODAC/O2 is connected to my computer, while the X is connected through my iPhone 5, although for linearity's sake, I'm using the same 24/48 Apple Lossless files in iTunes as in my iPhone. Also, it had better center focus, which makes vocals more appealing. What's weird was, on some recordings, the sound would be extremely veiled, yet on other recordings, it wouldn't be as large of an impact... However, the majority of the songs I listened to did not exhibit this behavior. This is very much like the HD800 where the sound would completely change occasionally with some recordings.
I think the X is not subpar in comparison to other gear in its price range, especially for the fact that it's an iDevice compatible DAC/Amp combo with a slim form factor which gives it the upper hand in ergonomics/aesthetics and ease of use to the Apex Glacier and Fostex HP-P1 respectively. However, it is one of those gears that are specially reserved for a special group of people, in this case those who prefer lush mids, who cares not for treble extension, or with cans that can somewhat balance out the sound... My ES5 did not pair too well with the X due to its already lush mids, slightly recessed upper treble, and less sub bass extension.
If you get past the lack in treble shimmer, one can really listen to the X for hours at a time if battery allows; there's absolutely no fatigue at all. I actually appreciate its completely smooth sound in some recordings, and dare I say it may even be slightly 'seductive.' I've been listening to it almost straight for around three hours now, and the sound really grows on you. At first, I did not like it at all, but I've now grown to the sound. I will report back in a week's time if anything's changed.
One thing that I disagreed with shotgunshane was that I'd rather have the X's battery last longer than keep my iPhone constantly charging and have the X reduce in headtime. Sometimes I'd appreciate the charging, but if it was an option that was able to be switched on or off, that'd be incredible, because most of the time I'm around a usb port (my macbook) where charging is accessible. However, I can definitely see this as a very useful option because the iPhone's battery drains so quickly, especially with an external DAC that sucks extra power. Ironic because I complained that this should be a feature of the CLAS (when I had it long ago) due to its draining my iPhone's battery as if it was drinking water.
Quote:
Venturecraft Go-Dap X impressions:
The X is very nice size that matches up with the iPhone 5 just about perfectly. Controls are somewhat counter intuitive, especially activating the bass boost. It requires holding the battery button down until the switch on the front blinks, then flipping said switch down and back up - to deactivate bass boost, follow the same process. The best feature is the auto charging of the iDevice. The convenience and importance of this should not be overlooked when considering an all-in-one amp/DAC device for traveling, especially for an iPhone. It’s so convenient to listen with the X for several hours and have your phone still fully charged when you’re finished!
The X I used is the black version with the Burr Brown OPA2134. I find the description from VentureCraft, to another head-fier (earlier in this thread), of the black X to be pretty accurate: “focuses on and enriches mid and high pitch really well…”. Basically I find the black X to have a midrange focus with a bit of an upper mid/lower treble edge; bass is slightly less impactful. This makes for an engaging or musical presentation. Those observations were made versus the stock iPhone 5 with the GR07 mk2 and TG334. With the GR07, these changes are less apparent than with the TG334.
I also compared the X to my Leckerton UHA-6s (OPA209) both via computer and with iPod/iPhone. The computer connection was using both their DACs and amps, whereas with the iPod/iPhone, I was using the Leckerton as an amp only (so not exactly an apples to apples comparison but worth noting none-the-less).
From the computer, with the TG334, the differences were quite obvious. The X is much more upfront and upper mid/lower treble focused. The overall presentation is brighter, closer, musical and aggressive. The X midrange is definitely the focus. The UHA-6s is more transparent, articulate and spacious. The Leckerton’s bass had more slam and better definition, as well as cymbals rendered more articulate, even if not as bright as the X. These observations still hold true with the iPod/iPhone but to a lesser extent, since the Leckerton was using the Apple DAC.
I prefer the Leckerton to the X, as I am more focussed on detail resolution and transparency and I find the UHA-6s to do this in spades. Its amp and DAC section are simply excellent IMO but if I did not already own the UHA-6s, I would be perfectly happy with the VentureCraft. It’s simply fun and engaging. It definitely gets the head bobbing and the small form factor combined with the charging feature is something I definitely desire; it will be hard to give that particular feature up!