I've had a number of people PM for impressions about how the ODAC/O2 stacks up to the UHA-6S MKII. I briefly compared DAC/amp sections of these two rigs.. then offered some thoughts on how the amp sections of the O2 & UHA sound (when driven from the ODAC). I thought I'd post one of my more involved (see: long winded) answers here since it might help others. Obviously, these are my
personal impressions/opinions, don't go crying to mommy if you disagree, yadda yadda yadda..
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The ODAC/O2 & UHA are quite similar in performance. In the fairly extensive time I've spent comparing the ODAC & UHA's DAC section, I found the ODAC to sound superior. Since I listen to both these rigs quite often, the differences are fairly easily distinguishable to me.. but in more general terms, the differences aren't as stark or lopsided as some HF members claim. The UHA's DAC is more than capable DAC, IMO. If I rated the ODAC as a 9/10.. the UHA's DAC would probably be an 8.25/10 or 8.5/10, IMO. Vs. the UHA's DAC, the ODAC features a more multidimensional soundstage, better dynamics, cleaner instrument separation, and better overall clarity/transparency. The UHA's amp is really good though.. very clean & transparent... perhaps slightly smoother sounding than the ODAC... but it lacks some of the depth and effortlessness the ODAC boasts.
Some criticize the UHA amp's OPA209 opamp (which is beautifully resolving, neutral, and tight, IMO) for not possessing a wide enough soundstage... but what I discovered is that the UHA's
DAC does a nice job of complimenting this so-called 'shortcoming' in the OPA209 opamp by offering a pleasantly wide soundstage. This is an often unmentioned and/or overlooked characteristic & a nice touch of synergy between the UHA's DAC & amp sections. Unfortunately for the UHA's built-in DAC, the ODAC offers an
even wider (and deeper) stage along with better resolution. While I enjoy using the UHA as both a DAC/amp, pairing the ODAC with the UHA 's amp section (which is my primary portable rig) is an absolute beast of a setup.. one that's so impressive that it'll probably satisfy many people's portable rig search for the foreseeable future (well, at least for for me, anyways).
Using the ODAC with both amps, the most significant strength the O2 has over the UHA's amp is the ultra-wide soundstage & slightly better dynamic range. The O2's has a really impressive, open stage that possesses a very "live" quality. The UHA's amp is no slouch in this category.. but the distinction can be easily observer (golden eara not required
). While the O2 sounds a little smoother, more substantial & possesses slightly more bass punch/impact than the UHA's amp, the UHA amp's bass response is slightly tighter, faster, and possesses a little more PRaT. The UHA's amp also features a lower noise floor from my experience so you've got an even quieter/black background than the O2 (which is amazing). Pair the UHA with the dead silent ODAC.. and you'll 'hear' one of the blackest backgrounds in all of portable audio Comparatively vs the UHA (OPA209), the O2 might sound a little more 'musical'.. but the UHA sound like the the more accurate, cleaner sounding amp to me.
I like that the UHA's low gain is set at 1X.. it makes using it with IEMs quite easy since unity (1X) gain typically allows more of the volume pot to be utilized with highly sensitive IEMs. The O2's low gain is at 2.3x (or 2.5x?).. but it performs nearly as well with highly sensitive IEMs. I mention this more for informational purposes.. in real world use, i didn't have any problem using sensitive IEMs with the O2's low/default gain. Less of the O2's pot was at my disposal.. but it was past the point of channel imbalance.
I like having both the O2 & UHA amps at my disposal since I have the HD600 & Paradox (two phones that benefit from the O2's higher output power).. but the UHA (in high gain mode) drives these full sized phones quite well, too. The UHA's high gain sounds more linear and better controlled than the O2's high gain implementation, IMO. The UHA as an all-in-one DAC+amp solution is plenty impressive.. especially since it can be used with the Galaxy S3's OTG cable/USB audio output. Using the ODAC with the S3's OTG/USB audio has been less reliable/inconsistent IME.. it doesn't work less often than it does, for some reason (I'm running the stock Verizon/TouchWiz JellyBean ROM.. not rooted/unlocked/modded).
The ODAC/UHA provides enough of what the ODAC/O2 offers as far as soundstage.. while featuring slightly better resolving ability (than the ODAC/O2 combo), better battery life, and more versatility (digital & coax inputs).. all in a smaller, more compact, sexier, portable package. The ODAC/UHA's cleaner sound has excellent synergy with the slightly warm, vinyl/analog-tinged character of the BA200, too.
My recommendation would be to get the ODAC & feed it to the UHA-6S MKII's amp section. You'll get the terrifically transparent, dynamic, multidimensional, and highly resolving qualities of the ODAC along with the clear, tight, fast, PRaT-excelling quality of the UHA's amp section (with the OPA209). This is my go to portable solution & I
couldn't be happierwith the sound quality. Recently, I had been eyeing the TTVJ Glacier and Portaphile 628 amps as potential upgrades to the UHA. Those might be something I consider down the line.. and out of sheer curiosity.. but for now.. as I have spent a significant amount of time with the ODAC/UHA stack (and the ODAC/O2), I grew to really appreciate and become incredibly content with the terrific sound quality both these setups offer. If it wasn't already apparent, I slightly favor the ODAC/UHA combo, though.. it's thoroughly satisfied performance requirements in a portable rig and I can't see myself letting for of it for the foreseeable future.
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So I guess you don't need an expensive unit to reap the benefits. In any case, I can confirm that laptop power supplies can be noisy with the ODAC.
