I just returned from the Can Jam at the Rocky Mountain Audio Fest. I listened to every headphone amp I could get my hands on. There was a lot of background noise with people talking so I had to settle for my trusty Shure E5C for the test. Amps over $1200 sounded more detailed. Otherwise, I am very happy with what I have.
Similar to the previous review, I have a RockBox mod on my H120 which must be run through an amp. Without the HeadAmp Pico, any good headphone doesn't have a chance with the old H120. With the HeadAmp Pico, the FLAC files sound great!
In addition to the Shure E5C, I have the AKG K702. Where the E5C is very accurate, the HeadAmp Pico makes the K702 sound warm. Yes, this is quite contrary to most of the reviews written about the K702.
Lastly, I just purchased a pair of HD800's. I was told to expect the HeadAmp Pico to not be able to keep up with the impedience swings required by the HD800's. Well, the horror stories were not true. Yes, I plan to upgrade to a Grace M903 but I'm in no rush to do so. The HeadAmp Pico is keeping up just fine.
Because the HeadAmp Pico has the DAC, it sits next to my laptop every chance I get. I set Foobar to "Speakers (USB Audio DAC )" and let the HeadAmp Pico do all of the work. My 24/96 audio files sound beautiful!
I have returned to many recordings to listen again. That is how much I have enjoyed the HeadAmp Pico. Highly Recommended!
Pros - Great SQ and build quality, small size, good battery life
I primarily use the Pico at work to listen to CDs and for that it does an excellent job. Occasionally it's used amp-only with a rockboxed iMod or H140. In all cases it is a solid performer. The USB DAC is the main reason people buy it but the amp circuit is no slouch either. The soundstaging is great, notes are sharp and clear. Some people call it warm, I don't find it as such. It may be a tad on the expensive side, but the build quality and value that it delivers warrants the cost IMO.
In my case it's usually paired with AKG 271S or SE 530s pushing Rock/Jazz/Classical. If you have similar tastes, this would be a good choice for you.