The International Headphone Amp/DAC by ALO Audio

International by ALO Audio

ALO Audio has never been a company that rests on its personal audio laurels.  A steady stream of ever-evolving headphone products have graced our ears over the past few years, and from the pace of things it doesn’t look to slow down any time soon. The newest headphone amplifier and DAC combo looks to keep stride with its latest competition by including both inputs and outputs in the balanced flavor as well as the more traditional SE connections.  The ALO Audio International ($600) sports a 24/96 kHz USB DAC and an impressive headphone amplifier in a new smaller package.

The International Front Side by ALO Audio

The Build

The new size is a small departure from ALO’s previous headphone amplifier casings.  The design incorporates a much leaner depth with a slightly meatier height and is just a finger smaller than a pack of cigarettes.   The first thing that struck me when I picked it up was the weight. It has some real heft to it. I would say pound for pound it is a little heavier than similar-sized components out right now.  Not to say its actually “heavy”, but it does feel solid to the touch while remaining extremely portable, given its size.  The extra gravity is no doubt a contribution from the internal battery, which claims a 14-16 hour life for amplifier exclusive usage and 8-10 hours with the DAC section activated. The fit and finish is a nice combination of solid construction and just the right amount of texture and sheen for a metal casing. I would still consider the look to be a matte style, but it is still quite attractive when the light hits it. The overall build is just as solid as something portable needs to be.  There is no independent on/off switch on the unit, the rotating volume knobs clicks the power on as you turn it up.  I found the volume to be a wee bit jumpy on low gain with IEMs, but still much better than most amps in this range.  Even with its high gain/full size headphone capabilities, the International still does a great job handling IEMs.  I could detect no background noise on the lowest gain with my Jerry Harvey JH16s, a very nice black backdrop to lay your favorite tunes over.

International With the Sennheiser HD650

The Sound

If there are four observations I could leave you with regarding the International it is this: quick, tight bass, clean, and dynamic.

Like any good pool, the International boasts a deep bottom end.  Bass slam and impact are pretty amazing with this little unit. The low end feels really potent in your ears.  I was equally impressed with the overall dynamic feel of the entire frequency spectrum as it was presented.  Listening to a David Chesky recording of the Brooklyn Funk Band track Pamafunk I couldn’t help but notice the realistic grunt of the bass guitar and the sharp, accurate snap of the snare drum.

International Back Side

Vs. The RSA Intruder

The closest contender to the International is Ray Samuels Intruder ($700).  Even though the Intruder has a pretty good bass implementation, I found the International to have the edge in terms of punchier, cleaner bass and high-end extension. I also preferred the overall dynamics of the International as they seemed a bit more lively than the Intruder.  The Intruders DAC section differs slightly from the International’s 24/96 kHz Cirius Logic CS4398 DAC Chip.  The Intruders DAC tops out at 16/48 kHz, so high resolution files don’t get fully represented.  On the flip side, the DAC is one of the very very few than can properly connect with the Android Galaxy S III phone.  I could not get the International to properly connect to the Galaxy III via USB.  The Intruder’s DAC draws power from the USB connection while the International does not.

Vs. The ALO Pan Am

I was really impressed with the Pan Am ($500) when I first heard it, so I was quite excited to see how the two compared. I found the Pan Am to maintain its richness in the mids, delivering an engaging, fun tone without sacrificing any detail.  My unit is equipped with stock tubes, and with those tubes the vocals are just a hair forward in the mix.  Part of the fun of the Pan Am is rolling the tubes, so individual results may vary.  When paired with the Audeze LCD-3, I still preferred the richness of the Pan Am when listening to vocal-centric genres.  Diana Krall’s vocals on Peel Me A Grape seem to have a lifelike whisper to them though the Pan Am.  Where the Pan Am has a rib-shaking body shot, the International has bifurcated swing with a clean punch in the lows and highs.  I would recommend the International for genres where speed and accuracy play strongly to its amazing technicalities.

ALO International with Audeze LCD3

With The CypherLabs Algorhythm Solo –dB

Aside from full size components, the balanced input in the back of the International is primarily designed for use with the Algorhythm Solo –dB’s ($700) balanced output.  While the new size is a bit shorter than the dB, the two still can be lashed together with an iPod for a portable audiophile brick.  As it often is with audio components, the separation of church (DAC) and state (Amp) isn’t without its benefits.  I found the addition of the external DAC via the balanced connection to bring even better instrument separation and sense of three dimensionality to the soundscape.  Playing high resolution files from my MacBook Air via Audirvana Plus and the dB’s balanced output to a pair of Audeze LCD-3s was quite the audio feast and one of the top overall portable headphone systems I’ve heard in terms of realism and dynamics.  Of course this kind of setup is very revealing and is best suited for equally appropriate sources.  A quick comparison revealed a digitized aesthetic fuzz covering most of Spotify’s streaming music service, which took a little to get used to.

ALO International With CypherLabs Algorhythm Solo -dB

The Summary

Portable audiophile headphone systems are following much the same path as the rest of portable electronics.  Updates driven by new advances in technology make product cycles even shorter and devices smaller and better.  ALO makes it clear we haven’t hit the same plateau in personal audio that we are starting to see with the iPhone quite yet.  The International delivers amazing clarity, dynamics and bass section that is simply outstanding.  It may even make you forget everything you are hearing is coming out of a 3 x 3 inch box.



25 thoughts on “The International Headphone Amp/DAC by ALO Audio

  • GREAT review Brian!  Excellently worded my friend.  I’ve been enjoying this product for a couple weeks, and have fallen in love with it – over my beloved ALO RXMK3-B!  I still enjoy my Pan Am more w/ Siemens tubes, running on its Passport battery, but that’s my chosen desktop rig now.

    The International has become my go-to portable headphone amp.  I personally love its DAC section as well.I have to admit I’m enjoying listening to The Internation on my Audeze LCD3’s and JH Audio Freqphase JH-13s Pros – so I wouldn’t call it an “IEM amplifier” only because I would be afraid that might suggest it cannot power them.  It can, well.

    • Thanks for the kind words Michael.  I agree, the International has plenty of power to drive the big phones. I really enjoyed the amp with the LCD-3s as well!

      • what a combo! I was psyched to bring that rig to an LAOC Audio Society meet down in SoCal. One of the guys said something to another friend of his (they had to be in their sixties) that resonated with me: He said “that sounds almost as good as my high end stereo at home” “unless you’ve heard this, you’ll never know how good portable sound can be”…

        Workin on that piece right now bro

  • Yes, great review, and as always, wonderful images.

  • ” I could not get the International to properly connect to the Galaxy III via USB.”
    How about using the USB Audio Recorder PRO app available on the Google Play store ? 
    This app doesn’t use the Samsung-implemented USB audio driver. It includes its own USB audio function.

    • Success!  That took quite a bit of fine tuning, but I did get it working finally with the USB Audio Recorder PRO program.  In full 24/96 no less!  Had some issues getting it setup, but it can be done.

  • Re: International + Solo DB combination. What difference do you hear between balanced and single ended? Thanks

    • The difference between a SE connection and a balanced connection is noticeable.  The overall volume is actually higher.  Other improvements include a wider soundstage and a more lively sound.  This is true for both SE connections and balanced connections going to headphones (a balanced input still delivers a signal to a SE output).  The benefits are slightly less noticeable with the SE compared to a full balanced to balanced connection. I would recommend a balanced connection if possible to anyone who owns the Algo -dB.

      • Interesting thanks. With the upcoming Centrance M8 my intended transportable setup could go into any number of directions. Will you be doing a Dac-off in future given the number of interesting things coming out?

        • I fully intend to, yes.  I already have to update the 9 DAC video review.  You can check it out here but it is minus the new International.

  • Dear Audio Head,
    I am currently using a AK100 + ALO RxMk2 with several IEMs.I am thinking of upgrading to the International due to the matching form factor with the AK 100.I am wondering how the ALO International compares with the Rx Mk2/Mk3

    Thank you, 

    • Hey Samuel, that is a great question.  I did not have a Mk2/3 on hand for a direct evaluation so I can’t speak to a specific tonal comparison.  I will say that the International is a little more fine tuned for IEMs.  Given the additional DAC section and the smaller size, I would go with the International if it’s within your budget.

      • Thank you for your advice.
        Regarding the balance output of the ALO international, would i benefit from a balanced output to my UERM when i am only using a single ended input?

        • Hey Samuel, The International will indeed play balanced out from a SE input.  I do not have a pair of UE Reference Monitors to give you exact observations for.  I have heard the balanced output to a pair of JH16s and 1964 V6s.  The benefits of balanced output differs from headphone to headphone.  For those IEMs I have heard the biggest benefit is a wider soundstage.  For whatever reason, I think there is a nice effect from the internal DAC going balanced, but the SE input is influenced to a lesser degree.  

    • Samuel, it really depends on what headphones/earphones you are using. The Rx is always the best choice for very low Ω earphones. It sacrifices absolutely no resolution no matter what is plugged into it. However, at extremely loud volumes with headphones such as the DT880 600Ω, it gives a little dynamic ground to The International. 

      Despite perfect resolution with low Ω earphones, the Rx doesn’t supply as black a background as The International does. If nearly silent backgrounds are important to you, the International is the clear choice.

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  • Hello,
    Many thanks for the great reviews section as I’m digging deep into the topic. I’m looking for a portable DAC/AMP solution for my Sony MDR-MA900. Do you think ALO International would be the best investment, or maybe you’d recommend anything else (my budget is USD 200-600)?

    • Right now my recommendation is the International in that price range. I’ve had quite a few portable units in and out of the lab lately and I’m still pleased with it for $500. While the included DAC isn’t on the same performance level as the amplifier section, it still works great and contributes to it’s solid overall sound.

      • Thanks! Maybe you’d also recommend something more affordable for consideration (within USD 300)?

  • Sorry if this is a silly question — but is there any benefit to connecting the International and the Solo db via the balanced ports — but using single-ended IEM’s / headphones? I have both – and have them connected with a ALO mini to mini connector — but I see how you have the two hooked up here and just wondered.

    • Hey Bob. It may be one of those things that comes down to preference, but I found the dBs balanced output to be higher than the SE in this case, and my preference. So while this may not apply to every SE vs Balanced situation, for this one I prefer the balanced input on the International for both SE and Balanced headphone connections.

      • Thanks for that — I ended up calling Cypher to ask their opinion – they said the same thing – and said by connecting the International and Solo db via the balanced connects, you keep the audio signal intact longer. I’m going to give it a try and see.

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