Alo Studio Six Headphone amplifier

The ALO Studio Six Headphone Amplifier

The headphone amplifier James Bond would listen to music on


The following is a direct quote from the website


“In the 1973 movie Live and Let Die, Bond fixes M a cappuccino with this very loud machine while M is talking about the mission. M, after receiving his freshly brewed coffee, comments “Is that all it does?!”

Reading on, we see that M here is referring to our man Bond’s now classic La Pavoni Europiccola Espresso machine; a relatively unreliable, difficult to master though sexy-as-hell, lever-action machine which I myself (purely coincidentally) now happen to own. Incidentally—except when steaming milk for lattes, it is actually unnervingly silent, but I digress.

Now I frequent maybe once, twice a week in order to amp up my IQ (Intriguing-ness Quotient) and of course, whenever I find myself in need of say, a new Cuisinart.  I suggest you begin to do the same.  Then, like me, you may soon find yourself shedding your geeky audiophile image as you edge closer and closer to becoming (quite simply)—The Most Interesting Man in The World™.

The mid-century modern ALO Studio Six headphone amplifier, a Class-A, single-ended triode, zero-feedback design with a total of four(!) headphone outputs whose “tubes have been hand-picked based on their long established reputations for sonic virtue,” could equally well have been the object d’art to which M refers.  It’s a 26 pound, 16 inch wide tube amp with six tubes for listening to…headphones?!  Is that all it does, indeed. 

Arriving exquisitely well packed-n-padded, on first blush ‘tis indeed the Six’s sheer size and heft set off against its single-minded purpose – to amplify headphones – that gives one intellectual pause.

But you get over that “pause” in rapid fashion.  You really surmount it, entirely I found, while beholding the ALO’s spot-on, retro-modernist, Bauhaus-inspired design alone in a dim room for a stretch of time, listening to Mozart whilst awash in the subtle yellows of its exposed tube complement, all the while sipping the dregs of your Laphroaig Cask Strength single-malt.  Then you go from “intellectual pause” to something like, “I wonder if I could make more space on my office desk for it by tossing my 27” iMac out that window? I have an iPhone—that should be enough…”

Sure, muggles might think I could just plug my headphones directly into my computer or that iPhone, or perhaps into my splendid Burson Soloist headphone amp or even into a “cheap-n-popular” $150 Flio headphone amp. But thenwhat would I do with $3,500 or $4,000 of “disposable” income?! Tell me! Charity?! Music downloads?!  Aha, many, many pairs of – approved galoshes!! Honestly people.

Okay, maybe music downloads, but then I’d miss out on the commentary of several recent visitors to my apartment who, upon regarding the Studio Six, mostly said things that amount to, “A headphone amp? Is that all it does?!”

In essence,four thousand bucks to step into James Bond’s Church’s shoes?! You better f-ing believe I’d be a buyer!

Really, Seriously. Is That All It Does?

Well yes. It’s a headphone amp. That’s all it does. But it’s how it does it and how it makes you feel while it’s doing it that makes this single-ended beauty worth the considerable real estate it occupies in pursuit of “one true thing.”

10 or 15 minutes after kicking the tires and lighting the fires, the Six began to radiate its suave sonic retro-modernity with (surprising) emphasis on the modernity in my general direction. “This is single-ended? This is tubes?”  I thought I heard myself muse… to myself.

I long ago disabused myself of the notion that all solid-state gear sounds “solid-statey” (read: sterile and bright) and tube gear sounds “tubey” (read: warm and syrupy), though naturally, the ghost of truth still haunts such stereotyped houses from time to time.

Rather, the Six gave me a totally grain-free, detailed and relatively “neutral” presentation with no drama, and I mean that in the very best possible sense.

Nothing was underlined or omitted.  There were no whiskers on pigs or lipsticks on kittens or whatever – not a lot of “tube-sound” or “solid-state sound” to speak of. But there was a lot of “suchness” in the sound.  By this I mean the musical presentation through any of the several headphones in my harem seemed utterly effortless; as though the Six was barely working whatsoever and as though what was recorded was what was conveyed.  Comparatively, my trusty Burson Soloist added a bit of fine grain to solo voice recordings and could not quite muster the general utter musical limpidity of the Six.

This feeling could best be translated for the purposes of reviewing to mean that the Burson’s presentation felt just a bit more “tense” than the Six’s, no matter the genre. So, too, its “stage” was somewhat narrower within the bounds of my skull and the Six also seemed to reveal more fulsome bass on my symphonic and operatic recordings.  Indeed, the tautness and improved depth of such low down rumblings told me the Six was likely ‘revealing’ such depths rather than puffing up some mid-bass frequencies to give the illusion of sonic heft.  I detected no tube-mediated top-end roll-off whatsoever.  To the contrary, strings and colorarura sopranos sailed when it was theirs to sail and were never congealed or the slightest bit congested on recordings not blighted by such artifacts.

To their considerable credit, both the 600 dollar Soloist and its pricier brethren, my reference Burson Conductor (whose wonderful internal DAC I used for much of this comparison), had a similar tonality to the Six in that both might be considered very slightly on “warm” of neutral. [N.B. your version of what “neutral” tonality is may vary, though it seems for example, that ‘phones such as the LCD-2 are considered on the dark side of the force in general and ‘phones such as Sennheiser’s flagship HD 800’s, on the bright side. It is in this general vein that I make such generalizations about the Burson sound and that of the Six. YMMV.]

Power wise, both amps could drive the Dickens out of pretty much any phone I threw at them.

Both amps let me easily hear differences in DACS – the slightly warm, less detailed albeit rhythmic and grain-free presentation of the Arcamir DAC as compared with the more lit-up, detailed andseparated sound of the DAC in Burson’s Conductor. 

More impressively though, the Six also caused me to grab my “bag o’ cables” from out of the downstairs storage unit (something I haven’t been moved to do in a long while), mostly because who knows what manner of sizes and shapes the midtown rats come in these days. No, mostly because cable comparisons go from exciting to neurotic and boring in short order. The Six’s unforced detail retrieval and general suavity however, proved the perfect persuasion as per my long languishing interest in any cable mano y mano.

Safely returned from my storage room safari, the Studio Six allowed me clearly and easily to identify the sonic signatures of the various after market AC power cables (I had forgotten) I owned, and let me tell you, the cable I preferred with the Six was (drum roll)…the one it “brung ta dance wit.”

I thought this was fitting, as ALO’s Ken Ball made his good name in large measure by offering after market headphone cables, power cables that many regard as upgrades as opposed to jewelry or side grades. In fact, industry people whom I consider to have good ears (read: similar taste to mine in sonics) like Vinnie Rossi at Red wine Audio, have long listened through and recommended ALO cables.

I’ll spare you the entire cable blow by blow, but a close second was,unsurprisingly for me, the stock generic black cable that came with my Burson and most of your own components.

Now I remember why I stopped comparing power cables- I usually ended up preferring the stock ones to the either too diffuse or overly lit up or in some obvious way “altered”sound of the aftermarket ones at my disposal.  I still (mostly) do.


Cons of a Pro

Other than compactness and weight,there was one clear advantage to the Burson amps; namely, via my more efficient headphones (Audio Technica’sath-AD900x and the Shure 1840) the Burson was dead as a door nail quiet, whereas I could hear a persistent very low level transformer him from the Six. This was certainly evident in a quiet room through high-efficiency headphones with no music playing, but did not intrude upon the sonics of the Studio Six.  Still, it’s there and others on the Internet that have mentioned it in passing.  Now this may in fact be a small though unavoidable consequence of gear with a big set of transformers direct-connected to your ears via the expensive sonic microscopes which are the audiophile headphones we all enjoy, and if so—so be it.  Didn’t bother me none even with my most efficient headphones. I mention it as it seems to be endemic to the Six itself and not caused by my outlets or particular wires etc.  Of note, through my ALO-cabled 600 ohm Sennheiser HD 600’s, it was much less apparent. 

Otherwise, the Studio Six functioned flawlessly throughout my months with it.  I would particularly like to single out two of the Studio Six’s features for extended Bravos though; firstly the volume pot,and secondarily, the presence of four headphone jacks. 

As for the volume pot, I hereby award it its very own “Most Wanted Component” badge for being the downright-est most solid-est, silkiest and best “feeling” knob I’ve ever twiddled.  And I’ve twiddled my share.  Yes – you can quote me on that. Just not out of context.

That knob and the one adjacent- the Six’s input selector knob- are to my mind studies in “knobbery” (or whatever such a science is called) and I definitely preferred this volume control to my Burson’s rather coarsely-stepped attenuator and for that matter, to any other attenuator, stepped or un.

While I’m on the subject of level, let me state that I think infinite adjustment of volume is keyespecially for headphone listening- where I find getting the exact right volume can be the difference between two hours of pleasurable opera in your easy chair and the soprano slightly over-blowing your ear drums on high notes every ten or twenty minutes or so.Then you have to get up (again!) and twiddle coarsely-stepped knobs and then you inevitably spill your scotch on the new BoConcept couch.  Anyone had any success training theirkitten and/or cat to adjust volume?  Just saying…

As for having four separate headphone outputs, I highly recommend it- especially if your social life is limited to three other people who like esoteric high-end audio equipment.  Indeed, I spent a couple evenings with an audio-inclined friend or two of mine running through their favorite tracks while switching between my four sets of headphones in order to determine a “favorite.”

Not only does this activity, like a pair of smart phones, obviate the need for any real conversation, it lets you suss out the relative strengths and weaknesses of all your ‘phones very readily.  There is a perceptible diminution of volume with the Six driving all four headphones at once and perhaps an attendant slight decline in sonic-quality, though very slight. 

The only limiting factor in terms of such potentially marathon headphone cage matches here, is the inability to optimize each headphone output for a particular headphones efficiency. In other words – do NOT switch to your Audio Technicas after you have been listening to the neighboring HD 600’s at a volume optimized for them, or your response-to-pain reaction time will be soundly tested.  You have been warned.

Shaken… and stirring

It should be said—and so I will say it—that the Six for all its 26 pounds and 3900 dollars, did not force me to laugh maniacally in the general direction of the notion of what I thought “GoodHeadphone Sound” was before its arrival. Specifically, my Burson amplifiers were in fact almost but not quite as expansive in terms of staging and were almost but not quite as revealing and almost, but not quite as grainless. Really— the two brands are neck and neck tonally— kissing cousins.  The bass on both is wonderful, but here again I think the Six takes things downtown a bit more to the hardcore.  It’s weighty, meaty and beefy—but not salient in its own right— just in accord with what seems recorded. And of course there’s the Six’s standout limpidity— its way with anything you play through it that seems to take the ‘tension’from the sound while leaving intact the pace, drive and drama.  And of course, don’t get me started again on the attenuator; infinitely adjustable, rock solid and silky smooth.  Studio Six Volume Knob, I shall always love thee!!


“Do You Expect Me ToTalk!!?”   “NO Mr. Bond, I expect you to…”


Buy… the ALO Studio Six. No I don’t.  Seriously, it’s like 3900.00 dollars and all it does is amplify music for headphones. 


Look, it’s like this: 


Yeah it’s mine.  The La Pavoni Europiccola.  Three shots total or so of Espresso and you’re out of water.  And the third shot is usually a bit too hot and the first one is usually too cold.   And then there’s the burning yourself frequently on the boiler thing.  Okay, But damn!  When you hit it right, that middle shot is what it’s all about.  When they taste it, people go “wow- that’s friggin’ great coffee!”  So yeah—like the Studio Six, that’s all it does, but it does it with style and sensuality and Bond-ness.  In fact, the La Pavoni Europiccola is the second coolest gadget I’ve ever used. 

That’s right— the ALO Studio Six headphone amplifier is my new over-the-top number one.  And while it certainly does not perform a Judo wedgie upon my considerably less expensive long-term reference Burson amplifier duo, it is in fact somewhat “better.” [Read: Its conveyance of micro-detail and full-frequency range dynamics in an utterly non-clinical musically consonant way, coupled with is starkly beautiful retro-aesthetic and superb ergonomics makes it capable of being an end-game product for anyone who values time with their headphones way more dearly than that spent with family, friends and/or significant other(s).  And you know who you are].

Yes, the ALO Studio Six headphone amplifier is the most over the top, purpose built, Bauhaus-styled, heavy-assed piece of gear it has ever been my pleasure to share a scotch with, and that canonly mean one thing: I must immediately begin petitioning Daniel Craig to lobby the Bond script writers to allow James to make headphone listening part of his seduction ritual in the next mediocre sequel in order that the ALO Studio Six headphone amplifier might appear (however briefly) and subsequently be posted on 


This will serve to legitimize what has become an overarching conviction in my time with the Studio Six; namely that this is the headphone amplifier James Bond would listen to music on. Higher praise than that, no man can give.  

I bid you peace and a Happy New Year.




Studio Six Specs 
Price: $3900.00 USA              

Headphone impedance compatibility range: 8 Ohms to 600 Ohms

Maximum rated output power: 1,000 milliwatts into 8 to 32 Ohms

Amplifier input impedance: 95k-Ohms

Amplifier input Voltage for full-rated output voltage into various headphone impedances:

1.00V RMS  input for 4.0V RMS output into   16 Ohms

1.30V RMS  input for 5.7V RMS output into   32 Ohms

1.70V RMS  input for 7.5V RMS output into   75 Ohms

1.85V RMS  input for 8.3V RMS output into 150 Ohms

1.70V RMS  input for 8.2V RMS output into 300 Ohms

1.65V RMS  input for 8.1V RMS output into 600 Ohms

THD+N (1kHz input) at 1V RMS output into stated load impedances: 32 Ohms: 0.26%, 150 Ohms: 0.12%

THD+N (1kHz input) at 250 milliwatts output into stated impedances: 32 Ohms: 1.0%, 150 Ohms: 2.0%

Frequency Response -3dB (Referenced to 1kHz, 250 milliwatts output) into stated impedances: 32 Ohms:   6.0Hz to 39kHz

150 Ohms: 16.5Hz to 36kHz

Frequency Response -1dB at full-rated (2.83V RMS) 1,000 milliwatt output into 8 Ohms: 15Hz to 20kHz

S/N Ratio: 78dB (unweighted) below full 2.83V RMS output into 8 Ohms

Power and Battery             

Power (Mains) Compatibility:

100, 120 or 240 VAC (factory selected), 50-60Hz

Power Consumption:

65 Watts Maximum 



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