Pros: Power, balanced/single ended output
Cons: Battery life
I've owned two of these now and it's time to write a review. One I bought new last year (and sold on here) and one I bought used on these forums. To put it simply, this is the best portable headphone amp I have ever owned or heard. I used this with a pair of Hd800s, balanced D7000s and LCD-2s. It easily powered all of these with authority. There are multiple gain settings as well, for more sensitive headphones, although you have to take the amp apart to change this. The little opamp kit this comes with is pretty cool as well, its really quick and easy to swap them out and fun to play around with different options. Sound from this amp (stock) is pretty neutral. I did many comparisons with this and my Schiit Lyr (out of the single ended output from the PB2) and I can honestly say that I could not tell them apart, this little amp can really power anything with some serious force! My one and only complaint is the ridiculously low battery life of this amp. I would say based on my experience that this amp has a realistic battery life of 5-6 hours when fully charged. But I guess that's a small inconvenience for such an awesome amp!