It is very clear that the dac portion of the International+ is the star of the show, also that this amplifiers demographic is for people who need a small physical footprint in their home rig, a solid dac most of the time and a portable amplifier every now and then. Those who own the lower end – mid tier portable daps like the iBasso DX50 or the Fiio X3, Sansa players and iPods will enjoy the nice clarity boost the International will add in a portable rigging, however owners of the DX90 from iBasso, the Fiio X5 and similar will not really hear much of a clarity boost, nor will they experience much of a power boost either for hard to drive headphone needs. The International+’s weak output limits the potential and falls short to the likes of a number of other newer portable daps out there with high gain features, as well as falling short in overall clarity when used as a portable amplifier. For those who want a less warm coloration to their musical experience, I think ALO products in general are the way to go. They seem more monitor in tonality and exude a hint of brightness on the top end so purists of tone might consider the bass and mid range acceptable for usage, where as the treble may be a bit overly colored for those die hard snobs who demand absolute accuracy.
I feel the right way to look at this $599 device is to think of it as 2/3 usb dac, 1/3 portable amplifier. In terms of pricing, I see the dac function to boast a clarity on the $200-250 level, which isn’t half bad when you think about it because of its ability to function as both dac and portable amp when you need it. So long as the headphones aren’t 150ohm and up, I would say no worries and try to pick one of these up, I’ve always felt the general sound signature to match up nicely with the clarity most mid tier headphones can offer. Owners of the Philips Fidelio series, the Sony MA-900, Sennheiser HD598, Denon D2000 and similar great mid tier headphones will enjoy the ALO Internationals dac capability. I would not use this model with the higher end headphones out there, as I feel the clarity overall to lack, as well as the driving power to fall short in its ability to drive other headphones like the Alpha Dog with authority. I will recommend the International+ to anyone who wants a good, small dac that also owns some mid tier headphones with balanced cables. This is a good product that tries hard to please you no matter what you try to use with it and where you want to use it. It is a solid, well rounded dac/amp combo and will suit the majority well.
Frequency Response : ±1 dB: 5-50,000 Hz
Maximum Output: 12 V Peak to Peak
THD+N: 0.001% @ f = 1 kHz
Input Impedance: 30k Ω
Output Impedance: <1 Ω
RMS per channel, both channels driven
Output Power - Balanced: • 70 mW into 32 ohms • 100 mW into 50 ohms • 240 mW into 300 ohms • 120 mW into 600 ohms
Output Power - Unbalanced: • 70 mW into 32 ohms • 100 mW into 50 ohms • 60 mW into 300 ohms • 30 mW into 600 ohms
Battery: 3400 mAh Lithium-Ion (Sanyo UR18500F)
Battery Play Time: Min. 14 hours ( Amplifier ) / Min. 7 hours ( Amplifier + DAC )
Battery Recharge Time: 3 hours