Majority of those all-in-one battery powered AMP/DACs are similar priced, any recommendation which one stands out? Perhaps the market with high end portable players - do some of them serve also as AMP + DAC? (FIIO X5? But it looks like it is just a DAC and it is meant to be used with another connected AMP)
I personally like the ADL X1, but the FiiO E18 should be for its price a good choice.
Chord Hugo seems to be the category winner, but it looks like there is no other way to charge it, than to carry separate battery charger instead of charging it through USB.
I don’t look for any connection with iDevice or Android. I just need the superb portable USB powered DAC/AMP for my Macbook Pro.
£1,400 Chord Hugo
http://chordelectronics.co.uk/products-info.asp?id=92
£785 Resonessence Concero HP
http://resonessencelabs.com/concero/
£485 ADL X1
http://www.adl-av.com/products/headphone_amplifiers/x1/
$285 iBasso D12 Anaconda
http://www.ibasso.com/en/products/show.asp?ID=63
$279 Leckerton UHA-6S.MKII + ADA 4627
http://www.leckertonaudio.com/products/uha-6s-mkii/
$399 Leckerton UHA 760
http://www.leckertonaudio.com/products/uha760
$249 JDS C5D
http://www.jdslabs.com/products/84/c5d-amplifier-dac/
$159 FiiO E18
http://www.fiio.com.cn/products/index.aspx?ID=100000049935442&MenuID=105026002