ALO The National headphone amplifier in review – a new class

Handsome and powerful - and compact

After having created perfection in the Rx, ALO are free to experiment. Their first experiment, The Continental, is quite a hit, especially as it packs valves under the bonnet for a truly classical sort of listen. But as ALO explain, the use of limited valves means that the Continental has a shorter time on this planet. Enter The National, an amp that they reckon is the answer to the Continental. I can tell you right now: The National is a single box that can fill the void of both portable and living room headphone amp.

Frequency response: +/- 1 dB:10-100,000 Hz
Maximum Output: 20 V Peak to Peak
THD+N: 0.004% @ 16V Peak to Peak out into 600
Broadband Noise: : < Input Impedance: 10KOhms
Maximum Input Level: 3.5VRMS
Channel Tracking: < +/- Battery life ~ 15-20 hours

ALO love big batteries

Build Quality
There’s hardly an amp out there that isn’t made of solid metal. Most are held together with iron or steel bolts and display their guts on green boards. The National is no different. Well, that is until you scratch the surface. (Still not sure if that pun was intentional or not.)

Every port, every bolt, every switch sits in countersunk wells. The only plastic nub on the amp is the high/low gain switch, which sits in a veritable castle of a well. Strong o-rings guard the in and out ports. So don’t worry. Fat, heavy headphone plugs can be used with abandon as this amp is a tank. The National is is mottled, invoking little fear of scratching.

The National’s logic board has a cut-out to fit a large battery. Hence, the battery rattles around a little in its niche. If the rattling annoys you, wrap the battery with a few thin elastic bands. (A braver man can steal his wife’s foundation sponge and force it in. I’m making no suggestions here.) The upside to this is that changing the battery is easy as it isn’t held on by unnecessary adhesives. Also, there is less chance of a bad battery frying nearby components.

The only feeble component is the 12V mains adapter whose male bits don’t securely fill the female bits. I broke my old Atari Lynx female bit with a real needle of a male bit. I was 13 years old.

The ALO is a grown-ups’ amp. Be a smart audiophile and charge your National in a safe place.

Ergonomics and polish
Before you plug in your headphones, glory in the wonderfully spaced in and out ports, the smooth volume pot, the mottled fascia. One-over The National over a few times. The font, by gods! worship it!

I only wish I were a better photographer than I am. The National is hands-down the handsomest portable headphone amp I’ve handled. No line is wasted, no item is out of place. No other amp compares.

This attention to detail is the best evidence I can find that ALO listen to and use the products they design. Let me try a little creative writing to illustrate how well thought-out The National is.

ALO’s Ken Ball is reading a mystery novel late at night on his iPhone. His wife sleeps beside him. Of course he has his favourite Ultrasone headphones plugged in. Peter, Paul and Mary are happily puffing away inside his eardrums. The novel just so happens to have been an iTunes gift, and contrary to the excited praise it received from the self-proclaimed mystery-loving friend who gifted it, it is a bore. After three mind-numbingly awful chapters, Ken shrugs his iPhone to his nightstand and and the room goes dark. But upset at wasting his time with the novel, he keeps The National on. He just needs more Peter, Paul and Mary. This Land is Your Land washes over him and he feels better. His wife happily snores beside him in a soft darkness till visions of the Magic Dragon overtake him. Not once does the glow from The National’s power lamp bother him.

Friends, this amp is great for use at a bedside. The lamp is lit just enough to tell you it is on, no more.

In short, I’m still trying to fault The National somewhere. I’ve taken it as a personal quest. The mains adapter isn’t enough. The battery rattle is fixed with a bit of foam. That beautiful font haunts my quest. Give me another sixty years, we’ll have a bedside chat at some hospice or another. I’ll be glad of the company.

Perfect ergonomics

The National is a headphone amplifier, plain and simple. If you want gimmicks, look elsewhere – that is, unless you consider polish a gimmick. From the build of the case to the shape of the logic board to the in and out ports, there is hardly an amp out there that is as ergonomically designed, or as useful for a wide variety of headphones and earphones. Right, there is that cute nubbin of a gain switch. Oh yes, and an easily-swappable battery. And sturdy casing. And excellent left-right balance from the volume pot.

And… and… and…

I’ll see you in sixty years.

Sound quality
Polish and build are great selling points, but in the end, one buys an amp for listening, not ogling. (In fact, I’m not even sure ears can ogle – mine sure can’t.)

If yours can, go ahead. The National sounds great. Indeed, it is one of a handful of amps at this price point is even trying to make itself heard. ALO aren’t playing Toyota, moving the steering wheel a centimetre and calling it a new model for ladies. They aren’t undercutting everyone else’s prices by stooping to the same level of shoddy build. And they’re not rolling off the treble for a ‘rich’, ‘warm’ sound. The National is made to different standards in both build and sound. And that sound is lush in the midrange, and bright and powerful.

High-voiced midrange instruments have a close, intimate sound – an intimacy that isn’t strictly speaking, natural, for solid state amplifiers. That intimacy isn’t a blur, though. There is ample spacing between instruments, just not Rx spacing. The warmth may be the product of a very slight time delay in high-voiced instruments, something that I will for lack of better vocabulary, call a high-range smear. That hint of delay is an part of a sound signature that is built somewhat off of a valve-amp blueprint. I think it will find itself very well thought of in the living room and when paired with achingly treble-tipped earphones.

Now let’s talk space.

There is a lot of it in the low frequencies, no matter the type of headphone it is paired with. It is clean and powerful and taught with lively positioning. Its image is 3D, not wall-of-sound, with a tendency to warm slightly ‘behind’ the ears. In terms of attack and power, The National is in a space much its own. Sub-bass is ever so slightly rolled off, but a powerful emphasis beyond 60Hz, especially when paired with headphones such as the Ultrasone DJ1Pro, is prodigious. Of course, we are talking minutely here. No self-respecting amp would sound that different to the original wave without an external EQ circuit, so the prodigy I refer to is mainly the incredible separation and definition in the low frequencies.

This space continues well into the middle mid tones where instruments thrive in their own space. It is only in the higher mid frequencies that any sort of artefacts appear. As mentioned way above, some of these artefacts are part of ALO’s design. The minute delay is a wonderful effect though hardly audible. It’s a happy shadow cast in most music.

Under heavy load, harmonic distortion artefacts appear, though not enough to cause displeasure. However, if you are a user of complex multi-armature earphones of very high sensitivity and swings to low Ω, you may find that complex orchestral pieces aren’t as articulate as you would like. For you, I would suggest the Rx, which is completely adroit no matter your earphone.

But all of that is esoteric talk. No amplifier sounds completely different to its siblings and competitors. The National doesn’t transform you music into something else. Its primary job: holding signal when driving large and small loads, it does well. And whilst that is going on, The National throws in a bit of its own flavour. Can you blame it?

Regarding driving capabilities, The National is more powerful than an amp its price should be. It generally upholds high quality signal when driving multi-armature earphones, and with voltage-hungry headphones, it sustains distortion-free signals even at intense volumes. I am a Beyerdynamic DT880 lover. My DT880 have 600Ω under their bonnets of mesh and steel. Plug them into an iPhone and older recordings are dead, soft, indistinct, and boring. Why? The iPhone hasn’t enough voltage to supply volume for an engaging listen.

With newer recordings, the DT880 can get to good volumes from an iPhone, some in fact, too loud. But, press those recordings to volumes of over 90% (which are necessary) and the iPhone’s in-built amp begins to distort. Not so The National. All the way till 95%, its signal is full, engaging, and fierce. Too fierce, in fact, for comfortable listening. I keep the volume pot at 60% or under in low gain with the DT880, and even at that seemingly tame volume level, I’m probably doing my ears no favours.

More impressive is the pairing of The National and Audio Technica’s ES10, a headphone that can easily cause phase distortion when paired with lesser amps and driven at loud volumes. Plug it into The National and suddenly I feel sorry for it. I can crank The National’s volume pot to 90, to 100% even, and only the faintest hint of sizzle comes from the drivers. It’s a tough life for a portable headphone.

What if you’ve got a nice home system? Or you have a Cypher Labs Agorhythm Solo, or a Fostex HP-P1? How bout a nice home CD player? You are in luck. The National scales up to higher input levels perfectly. Though it will power the DT880 to dangerous levels when fed by an iPhone, a proper line-level system allows The National to reveal even more power.

Charts Disclaimer
This review’s RMAA measurements reflect the performance differences between the naked iPod touch 4G and the same iPod when paired with The National and ALO’s own line out cables. Since these measurements are taken with my equipment, they should not directly be compared measurement-to-measurement to other technical data taken with different equipment. The data represent the ability of the amplification circuit to drive headphones and speakers.

*UPDATE: true side-by-side comparisons will be uploaded this evening. Currently, that data is garbled and the only data available is The National paired with the Cypher Labs SOLO and strapped to the Earsonics SM2, a very difficult-to-drive earphone.

Loaded frequency response
Let’s get onto the boring, objective stuff. Firstly, I would like to tackle The National’s ability to deliver signal both under load and when driving basically nothing. In this case, ‘nothing’ would be something like the Beyerdynamic DT880 600Ω that sucks voltage, but plays nice on amps because of its incredibly high Ω rating and low sensitivity, which induce basically no distortion except on the worst amps.

The National is hardly one of those. As mentioned above, it doesn’t reach the same level of performance as the Rx with all manner of headphones and earphones, but come on, it’s cheaper, and honestly, sounds better with the likes of the DT880. Part of the reason that it distorts with multiple balanced armature earphones is that its output impedance is higher. If an earphone drops below its output impedance when under load, The National will distort.

Just such a one is the Earsonics SM2, which remains the hardest driving universal earphone in my arsenal. As you can see, The National struggles a bit with the SM2. It does no such thing with the Sleek CT7 or the Audio Technica CK100, both multi-armature earphones with relatively low Ω ratings.

However, ‘struggle’ needs reference. RMAA indicates that under the strenuous load of the SM2, mean deviation is far less than a decibel, and exceeds 0,5dB only in the higher frequencies. Such small deviance may or may not be audible. I tend to take the stance that a deviation of around 3-5dB is the lower bounds for audibility.

In short, The National does its job well.

Loaded noise and dynamic range and distortion
Here The National begins to show some of its roots. ALO called on The National to “make the Continental last”. The Continental is a high-end valve amp that many audiophiles are clamouring for. The National, made of more readily available parts, is the answer to a limited Continental. Evidently, ALO had mind to design The National after the Continental – at least to some extent. Valve amps are known to be warmer, smoother, or more temperamental. Discerning audiophiles love valves, especially one unmentionable: distortion.

Let’s be honest here, the whole push forward in digital forged new, low-distortion paths. But since then, truly analogue signal pathways have abounded. Why? People love distortion. It’s warm, it’s fuzzy, and when done right, it can sound nice. Both loaded and unloaded National measurements prove the same thing: there is a small amount of distortion in the signal.

The National almost reaches 91dB of dynamic range. We all know that the dynamic range of 16-bit audio is 96dB, so the mark isn’t far off, but then again, I don’t think Ken was shooting for perfection, he was shooting for sublimation. Perfect benchmark performance is the realm of the Rx; The National is a product with a signature, not a signature product. I may have that backwards, but I don’t see how that matters. This is audiophilia anyway.

91dB of dynamic range gives a good indication in the levels of distortion you may expect from The National.

Loaded and unloaded stereo separation
Overall stereo separation is very good when plugged into most headphones. Again, complex multi-armature earphones cause congestion in the signal. The National favours the upper mids. There is more space and definition in mid range instruments than there is in bass and treble. That said, the difference between all three is small unless you are driving something like the Earsonics SM2. The DT880 600Ω throws no monkey wrenches at The National in any form and both low and mid frequencies are fully clear, detailed and wide.

In wintertime, I can think of no caveats to The National. It’s summer though, so I’ll shoot. It gets warm. I’ve got it in the front pocket of a pair of Asics running trousers. My right leg is sweating. Don’t worry, it’s not enough to burn you, but dear me, The National packs a heating unit in there, too!

I’ll need some company in the hospice. ALO have proved themselves again and I’ve no straws left. No niggles to pick. It its price range, The National is the best I’ve laid hands on. It is also the most interesting. ALO have taken a daring step by designing an amp that has a sound in a price bracket that is devoid of character. The product is almost limitless power for most headphones and ability to scale up with proper sources. In fact, if you were to plunk down 300$ on a single box and call it quits, my recommendation is to go with The National. It fulfils all your portable needs and doubles perfectly as a headphone home amp when fed by powerful sources.

ALO’s precision build and ergonomics are perfect, its sound nearly so, its polish, legendary. The National is defining a class all its own. And now, I must prepare for a long, hard vacation at the hospice. [To anyone, really] you’re welcome to keep me company.

App Summary
Title: ALO The National headphone amplifier Developer: ALO Audio
Reviewed Ver:  Silver Min OS Req: 4.3
Price: 299$-400$
  • extremely powerful output
  • wonderfully detailed, warm sound
  • best in-class built quality
  • oh God! that wonderful font and presentation
  • Price
  • not able to sustain perfect signal under hard loads of complex multi-armature earphones
  • battery wiggles

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