I'll be reviewing it with DAC section in use first since its plugged in and I'm enjoying it atm, so the memories of it are forming as we speak. I've had this unit for a couple of weeks now, and it probably has ~100 hours on it, not that I believe it matters. The general consensus on Headfi is that the Pico doesn't change much with burning in, and unless something dramatic happens from now onward, I must say I agree.
The Pico configures itself as easy as you would hope for, just plug it in and you're ready to go, well almost anyway. You might need to restart the program that plays music (in my case I just use iTunes) and it should work perfectly.
I've pretty much gone through most of the better parts of my music library with the Pico and my RS-1s, but I'd be using the less embarassing/ controversial ones for this review.
Diana Krall: Live in Paris - Just the Way You Are
Coldplay: A Rush of Blood to the Head - Clocks
Pink Floyd: Dark Side of the Moon - Money
Dream Theatre: Scenes from A Memory - Through Her Eyes
Eagles: Long Road Out Of Eden - No More Cloudy Days
The pico has one of the lowest noise floors, if not the lowest, among all the portable amps out there. From a purely objective point of view, that means that there will be no hissing, no static noise, etc, when there is no music, even with the most sensitive of IEMs. Musically, the song shines out even more, and from the moment you started listening in, what would strike you is the blackness from which the sound eminates (this is a good thing).
Details are fantastic, extremely clean across the entire frequency range. On Clocks, you can quite clearly pick out the twang of the guitars, making a very rounded, smooth end to every chord. The soundstaging isn't as wide in a lateral sense as the SR-71 (which was phenomenal) and the iQube but has an added depth and realism about it that I definitely prefer. For me, the music iQube especially felt Vocalists and intruments are very coming out from a single flat plan (albiet a wide one) unlike the Pico's which is almost around you, with the vocalist right in the centre, singing to you. While a direct comparison to an unamped RS-1s wouldn't be fair, it sufficies to say that using the Pico is akin to removing a huge veil between you and the musicians, bringing you right into the music.
The treble extension is fantastic, but not so much so it becomes piercing or uncomfortable, I think smooth describes it very well. The entry of the high notes on the piano, I think, (0:37 of Just The Way You Are) is almost like a bubble bursting on a summer morning, bright, sparkling, and really refreshing. On Money, the ringing of the change in the background is now even deeper, with an extra tingly "ching" to end off. A lady's humming to start of Through her Eyes has an added detail about it, you can almost imagine how she purses her lips and closes her eyes, and the huming pierces through the darkness and blackness.
The mids are, however, where this baby shines. Voices are warm, thick and extremely lucid. For me, this gives a perception that the mids are slightly forward, which is just how I like them. Live recordings really shine on this one, because of the human voice sounds raw and real. Details such as the performer taking breaths between notes come through, adding a sense of prescence to the music. It's almost as if you were there listening to Diana Krall sing from the front row. (I know some of you are actually going to do that this week, and yes I'm jealous, I booked my flight tickets way in advance and I couldn't change them) The Saxaphones are ridiculously awesome, I could replay the last thirty seconds of No More Cloudy Days for days and I wouldn't grow sick of them. The centre tones of the saxaphone notes seem to be even sharper, but the rest of the note is rounded off at each end, (which is exactly how a saxaphone is supposed to sound), making it such a pleasurable experience I think one needs to listen to actually believe.
The bass response is tight and taut, which is about as much as I need. It doesn't have the fullness of the Lisa III, not the depth of the Predator (although imo it is slightly more realistic on extended listening), but is enough. There is a toe tapping quality about the bass though, as bass thumps decays quite nicely.