You’ve probably noticed that I didn’t talk about the Pico at all in the comparison with the Audinst HUD-MX1 and the Dr. DAC Prime. The reason for that is that the Pico does come with a different kind of sound than the three above. Both the Audinst HUD-MX1 and the Gamma2 is very similar in its sound, and although the Dr. DAC Prime is less so, I would still group them together. In contrast, the Pico is quite different in its sound, and so it would belong in another group.
Before I set out to do this comparison, initially I have guessed that the Gamma2 would have the edge in sound quality. If we go by the “normal” convention that DIY products can be compared to commercial products 2-3 times its price, the Gamma2 then would be comparable to commercial DACs in the $400-$600 range, which makes it pretty tough for the Pico to match. After spending sometime with both, however, it’s clear that my prediction was way off.
To begin with, I don’t hear any advantages of the Gamma2 when compared to the Pico. They do share the same chips, from the USB controller, DAC, and to the ASRC upsampler, and so roughly their performance is roughly in the same ballpark. You’re not going to hear that one is more detailed than the other, although the Pico, being slightly darker sounding, may sound a little less detailed at first impression. This makes the Pico slightly less ideal, in my book, for low level listening. On the other hand, the Gamma2 is a little brighter than the Pico, and it’s easier to spot the details on it.
After long term listening, it becomes very obvious that these two DACs are very different in terms of sound signature and presentation. Aside from the bright & dark differences mentioned above, the Pico DAC has a fuller body and a weightier sound. It’s also warmer sounding than the Gamma2. What really separates the two DACs, however, is in the subtle things and the little refinements. Clearly, the Pico is the DAC for the audiophile. It’s warm and full bodied, but it’s also more than that. I slowly noticed that it has a very good timbre, and that ambience and nuances is very good and clearly above the Gamma2. On the Pico, each instruments in the Jazz in the Pawnshop album gets a proper body and weight to the sound, where on the Gamma, they are dryer, thinner, and less palpable. From the electric guitar, the saxophone, to the piano, the Pico reminds me a lot of the sound of the HM-801 player. Not to mention vocals as well, the added weight in the vocals are much more welcome. This difference in the weight and body really breaks the Gamma2 for me, and regardless of the genre I’m playing, from Rolling Stones to Rachmaninov, I find myself wanting to hear it through the Pico more. If I consider the Gamma2 to be a fairly neutral DAC, then the Pico is definitely colored. But it’s coloration is tuned in a way that it would enhance the musical experience of the listeners.
Moreover, while the Gamma2 has an airier sound and a larger soundstage than the Pico (two traits that I love), instrument separation is not as distinct in the Gamma2 as they are in the Pico. The Pico has a blacker background than the Gamma2, and with good attack and decay, I find that the focus on individual instruments is better on the Pico.
While the Gamma2 is a good DAC by itself, after considering the effort that needs to be made to complete the DIY build, the significantly larger size of the DAC unit, the added bulk from the external power supply, and the build quality of the two products, I would heavily lean toward the HeadAmp Pico DAC if it was my purchase. Personally I am not a big fan of the high gloss finishing of the Pico, but when I consider the whole package including price and the sound output, the Pico suddenly becomes a very good alternative.
What’s more, though the Gamma2 (along with the Dr. DAC Prime and the Audinst HUD-MX1) does a great job in converting digital signal into analog, the Pico with its own colorations somehow manages to be more than just a digital-to-analog converter. Yes, the Pico is not neutral sounding, but at the same time it’s closer in giving the “audiophile” sound often found in high end systems.
System for review:
Headphone: Sennheiser HD800 with APureSound balanced cable
Amplifier: Doobooloo’s Balanced TPA6120
Transport: MacPro, Itunes 8
DAC: HeadAmp Pico, AMB Labs Gamma2, Audinst HUD-MX1, ESI Audiotrak Dr. DAC Nano
Interconnects: Monster Cable Interlink 400 Mk2