Xavier,
Sorry it's not Bottlehead based, but my new portable system consists of a iPad Mini, a Lightning to camera connection cable, a standard usb A to Mini-B, an ALO Internationsal and a set of balanced HiFiMAN RE-600 IEMs. This setup will work with any lightning based IOS device -- iPod 5g, iPhone 5G and any iPad with a lightning connector. This sends a direct digital stream to the ALO International (24/96 DAC and amp, all self contained, battery powered and SE and balanced outs). It is very compact, convenient and can drive just about any headphone out there, and is very, very quiet with IEMs. I had Drew Baird at Moon Audio build me a RSA to female TRRS adaptor cable so I can use the RE-600s in balanced mode, and I have to say that I'm very impressed even at an early stage of break-in.
This is not for the kids, as one review said about the International -- no fireworks here, just a very nicee, balanced and mature sound -- a really good match for the RE-600s. Battery life on the International is about the same as the iPad when using both the dac and amp. This is some good stuff.
Also drove my Fostex Maddog's with ease.
No affiliation with any of the vendors mentioned above, but for me the thing I've been wanting -- a quality, portable daaac/amp setup that does not take any power from the host IOS device and still sends a direct digital stream.
This system rocks so well that I replaced my entire bedside table with it, but can also take it wherre I want -- aside from the iPad, the rest fits easily in a pocket -- the International is the smallest portable amp that ALO has yet made.
HTH, Jim
And apologies to the good folks at BH.