Katz's Corner Episode 9: Astell & Kearn AK T1p Headphones and AK380 Music Player

A Serious Listen: Astell & Kearn: AK T1p headphones
These Astel & Kern AK T1p ($1199) cans are among the most beautiful, striking designs around; an artsy, pristine piece. Beautiful brushed metal, luxurious comfortable pads, lightweight, produced by a partnership between A&K and beyerdynamic. This is a worthy sight on anyone's head. Smaller in diameter than my reference Audeze LCD-X, but still circumaural. Each A&K phone is hand-made, individually serialized: I'm reviewing #335. It comes with balanced and unbalanced cables, but I auditioned unbalanced.


I'm not a shy guy. If I don't like a headphone, I'll pull it off my ears within five minutes! So far, I've had the Astell & Kearn AK T1p on for over 40 minutes and I keep wanting to check them out—so there must be something about them that's keeping me listening. They call it a "semi-open" headphone...I don't hear any closed-in artifacts, they sound very transparent. Initially I find their sound attractive, warm, natural. But still there's something that's bothering me about these cans. I begin to feel they're a bit "polite", they never seem to kick with any recording. What's that about?

To get to the bottom of the matter I played one of my reference recordings, my own recording of Rebekka Pidgeon singing "Spanish Harlem" from her album "The Raven" on Chesky Records, the 176.4 kHz HD tracks "Bob Katz remastering, special edition." Now the issue becomes clear: There is a presence boost, centered at approximately 5 kHz. With the A&Ks, Rebekka's warm voice has become strongly sibilant. I know what she sounds like in person, plus, having heard this recording in many places, I know it is warmer and not so strongly present in the 5kHz range.

My diagnosis: the reason this peak comes on you slowly is that it is an extremely wide (low-Q) resonance. This is clearly a design decision on Beyer and A&K's part, to produce an immediately-perceived transparency that can be attractive to a lot of listeners. In contrast, a high-Q resonance (a sharp peak) can sound fatiguing, not the case with the A&K's, or they would not have passed my five minute test. In fact, they stayed on my head for a few hours! Too many headphones have instantly-identifiable sharp peaks in their responses, like the Sennheeiser HD 800's, but this is fortunately not the case with the A&Ks. These A&K cans feature second generation "Tesla" technology, which they claim eliminates even the last traces of resonance in the high frequency range.

Next, I check out some classical music: Also pre-installed on this A&K demo player, a high-res piece from Chesky, "Waltz of the Flowers", 24/96 from HD tracks, Bruckner Orchester Linz. This Tchaikovsky recording reinforced my impression...that these are destined to be classical music lovers' headphones. While I found the presence boost initially off-putting, it was easy to get used to, just a bit too "hi-fi" for this critical audiophile. But I'm sure these phones will be very attractive to any music listener who desires a lightweight headset that feels and sounds great. If only we could turn down that 5kHz range and fill in the lower midrange and bass just a hair, these A&K cans would be an amazing piece.

When I switched to my Audeze LCD-X cans, the Bruckner orchestra immediately sounded more attractive, with more warmth and body, string basses regained their drive. Then I switched to my custom-built M3 amplifier and the DAC from a Slimbox Transporter so I could play a wide variety of familiar sources from my collection in JRiver, alternating between the LCD-X cans and the A&Ks. I did not use any compensating EQ for the Audeze, so readers will get the raw dope. Since I have Rebekka's original master on my server, I replayed the song. With the LCD-X, Rebekka's romance was back, her voice instantly recovered its warmth and fullness. A bit too much, in fact, which was one of my motivations for equalizing the LCD-X in the first place. Still, her voice sounded more correct on the Audeze.

I do think this presence boost is the origin for my impression that the A&K sounds too polite. This is not a rock and roller's can... Steely Danners and Patricia Barberers will like the A&K more than Led Zeppelliners. Classical and jazz lovers could easily fall in love with this can, especially with its lightness and beauty.

Nevertheless, I strongly believe there does not have to be a "genre headphone": there is no such thing as a "classical music speaker" or "classical music headphone"—or a "hip hop headphone", though Apple and Beats would like you to think so. When a transducer is absolutely accurate, every style of music should sound right. But life is a compromise, and especially considering their great comfort, clearly the A&K's will satisfy a large group of listeners who like a relaxed, transparent sound and for whom power and punch are not high priorities. I know a lot of women (and men) who will fall in love with this combination of styling, light weight, and transparent sound. I definitely would not kick these beautifully-made, lightweight A&K's out of bed.

With the A&K, there's barely a wink of robust body and deep beauty. Though the A&K definitely have some bass, it's, well...polite. So personally, I keep returning to my Audeze—for as long as I can tolerate their weight. Still, you have to pay more than a $500 premium for the Audeze! Are there any more accurate headphones than the A&K in the under $1200 category? Do we really have to invest close to $2000 to satisfy our appetite for musical body and soul? We shall see, in future Katz's Corner investigations.

KatzCorner_Ep9_Photo_AK380 A Quick Look: Astell & Kearn AK380 Music Player
I'm privileged to be able to audition phones today using the premium DAC and headphone amp in the portable AK380 music player, which retails for a premium price: $3499. This player has a sharp, large LCD screen and is built quite ruggedly. Its custom operating system is easy to learn to use if you're comfortable with LCD touchscreen menus. The sound: scary good! In fact I prefer the sound of this battery-operated player more than JRiver feeding my Slim Devices DAC into my M3 amp! Amazingly, the portable player sounds warmer and more inviting than all my wall-powered stuff. I really hope it's just my DAC. I can use a new DAC, but not a new amp! I've been planning on building an ESS DAC like what's in the A&K for quite a while and this is my motivation.

We could characterize the A&K phones as being in the sonic minor leagues, but the A&K music player is definitely in the majors. The player is capable of feeding a good pair of cans to the limit of their ability—an amazing achievement for a portable device.


The player crashed on me three times in two hours during this review period. I had to do a soft reset, achieved by pressing and holding the up arrow button on the side with the power button on the top. This is not the sort of thing you'd expect from a $3500 device.

After resetting the player and going through the two minute reboot, I played a number of other sources through my reference Audeze cans. I heard great micro- and macro-dynamics, perfect separation and soundstage. It's very satisfying...the A&K amp is up to anything. I do like the sound of this box—if we can keep it stable. It's now the best sounding DAC in this room...what a revelation.

I tried to dip the 5kHz presence boost from the A&K headphones using the equalizer in the player, but I could not get its equalizer to change the sound, although the sliders were moveable, the sound did not change. There is a built-in "Pro EQ preset" which is not user-changeable but it did not appear to change the sound to my ears. In or out it sounded the same to me, at least with this software revision and this player model. What is the meaning of "Pro EQ" anyway? Equalization should be program or transducer-dependent, not a one-size-fits-all solution; that would be like putting salt and pepper on your food before you can taste it! Next I set up a user-adjustable-setting. Inserting the user-setting dropped the sound level perhaps 6 dB but none of its band sliders had any audible effect. Users of earlier models have reported success with the equalization so this must be a bug they did not test for.

I regret to say given this issue and the frequent crashes I cannot recommend this player at this time. If you are interested in this great-sounding player, make certain that A&K has solved the stability and equalization issues. Get one and try it out. I do not know the software release, but no one touched this player before I opened it from the factory-sealed box January 2016.

Editor's Note:

Ha! Welcome to our world, Bob. The amount of buggy and difficult to use enthusiast stuff is disheartening at times. In fact, when I reviewed Astel & Kern's earlier AK120 I found myself ready to throw it into the campfire by the end of the trip.


I've also reviewed the previous flagship AK240 and found the sound quality solid...but the user interface terrific! I'm shocked you had buggy issues. So much so, that I just rang up the folks at Astel & Kern and am having a unit shipped up ASAP.

I'm also tantalized by your impressions of it's sound. I thought the AK240 quite good, but not at the level you're describing. Sounds like I'm in for some interesting listening. I'll report back.

Thanks for your words, Bob!

tony's picture

Decades ago, at GM Corp, I maintained the Torque calibration Standards for Engine Performance measurements.

You, Sir, are the only reviewer ( I know of ) that owns musical Calibration "Standards" and uses them effectively to evaluate transducers and gear. Although, I value "Joker"
and Tyll's reporting, even to the point of the Trust level. Certainly, both excel as reviewers.

My acquaintances in Germany and Austria made me promise to give Beyer and AKG phones a home ( they know I'm a Sennheiser man ). I'll use this review to hold them off, at least for a while.

Those Koreans are competent Engineers, bet they'll get the bugs outa that 380 soon enough, even Apple and Google have bugs from time to time. ( I'm hoping we don't have any in the Driverless Cars as they're released to the public, fingers crossed, collateral damage on the Expressways will make us look bad ) .

If I'm JA, I'd say you gave both these reviewed devices an "A"! I'd imagine that Astel & Kern are feeling lucky you didn't slam em harder, I'll bet they're asking for a "re-test", I hope you give it to them. In future, these outfits should maintain closer contact with y'all.

Nice Review,

Tony in … New Hampshire with a guy on a Roll!

Bob Katz's picture

Dear Tony: Thanks. I don't know if even the Koreans can beat the obstacles of the Android. If Google has not matured the Android OS by this point so that the device won't crash 3 times in a single review, then I wouldn't get my hopes up. My opinion: A $3500 player should have a custom-built OS from the ground up, not use a generic portable cell-phone operating system. Imagine a self-driving car running on Windows or OSX? OS bloat is not the way to make a dedicated device. If they can make a touch screen microwave oven with a dedicated OS, they can make a portable music player without needing Android!!!

However (Tyll) as far as useability and GUI go, as I said in my review, I was very impressed with the A&K's ease-of-use. I don't know how to get material onto the device, however, and I get the impression you have to use their own ripping software and dedicated ripper. That would put me off completely.

If Tyll gets this model, I'll be very interested in hearing his reactions. It has an updated DAC and power amplifier. And let me know if the equalizer is working on it! If it is, then we'll have to compare firmware revisions and get to the bottom of that bug. That is one which should be within the power of the Koreans to fix.

tony's picture

Ha, good one.

I see your point and I can feel a bit of anger ( we all share ) in Consumer Audio products having ><)))'> and/or dubious traits.


logscool's picture

Interesting I didn't really expect at all to find out that the T1p is a good headphone after hearing reviews including Tylls take on the original T1. I assumed that the T1p was essentially a T1 gen2 which from what I've seen in measurements looks worse than the original and definitely more "peaky" than the HD800. Is this just a difference in opinion and taste between Bob and Tyll and other? Possibly but it sounds like Bob is talking about a completely different headphone. Tyll you should really get a pair of these for measurement.

Bob Katz's picture

Will be very interested if Tyll still has a T1 gen1 around to compare.

tony's picture

Wanna get into a nice brawl?

Stereophile's site has an Audioquest $1,000 HDMI debate in progress, 230 postings so far.

Here is another example of where owning the Calibration Standard is useful : We plug the HDMI cable into your calibrated system and evaluate the difference.

I wonder if you might offer your skills for a fee?

Tony in Michigan ( New Hampshire )

Bob Katz's picture

Dear Tony: Facebook has already a big brawl centered between Ethan Wyner and another gentleman about clocks. And about these dumb HDMI cables which Dr. AIX has rightfully exposed.

I designed and manufactured a dejittering box that once got Stereophile's Class A rating, but it has long been superceded. While making the rounds one day I visited a very famous audiophile friend in New York and we hooked the box into his system. He waxed rhapsodically. Then we inserted a new digital cable he had gotten and he didn't like the sound as much. But 15 minutes later he pronounced the sound had warmed up so the digital cable must have warmed up!

I just sat there internally chuckling. EVERYTHING YOU WANT TO KNOW ABOUT THAT STUPID DIGITAL CABLE CONTROVERSY CAN BE SUMMARIZED IN John Watkinson's excellent articles at Resolution Magazine, "The Cable Snake". Unfortunately I cannot find a free copy of the article on line. You will have to purchase a PDF of the July/August 2002 issue.

Here's a tantalizing one, though, available for free reading the speaker cable snake, also by Watkinson:

Digital cable:
Speaker cable: http://www.resolutionmag.com/pdfs/DRAGONS/SPEAKE~1.PDF

Bob Katz's picture

This is for Tony and anyone else who needs to give the final scientific answer to those who claim differences in digital cables. The article is "The Cable Snake", by John Watkinson, from Resolution Magazine, July/August 2002. Available for $5.00 from Resolution Magazine's back issues. Here are a few selected quotes from this seminal article:

"Exotic Cables seem to me to epitomise what is wrong with the audio business. Many years ago in travelling fairs, there would always be a quack doctor who peddled amazing remedies for ailments."

"Now there is nothing unusual about selling goods with an astonishingly high price tag, but usually such a price buys a degree of exclusivity, excellent after-sales service, and the satisfaction of being seen with a designer product."

"Let's look a the physics. There are three types of cable in common use."

"As for cables that are marked with arrows to show the direction of information flow; this is entertainment, plain and simple." [In another article, Watkinson demonstrates how to properly link shields in cables from one cable to another]

"Watch out especially for exotic cable terminology that applies to transmission lines, such as impedance and matching."

"No wonder that an exotic cable can improve the sound when used with sub-standard inputs". [in reference to DACs with substandard jitter rejection]

I wish I could quote more, but it's not fair to Resolution Magazine who gets a fair price for the reprint cost of this article.

tony's picture

I'm very much in agreement! and I love quoting you.

You and Tyll not being able to tell the difference between the Yggy Dac and the Antelope Dac was the high-point of Consumer Audio Journalism for 2015.

You, using your music standard to reveal the Beyer headphones performance is exactly the sort of thing we never hear from reviewers.

The "microwave oven" analogy is spot on!

Thanks for taking the additional time to discuss Wire, we got three important results from the two reviews. We got a bonus review.
I hope you get paid extra!

Tony, on the trail with Bernie

ps. you make exciting reading, I smile when I see you appearing on InnerFidelty [:-)> ( crew cut, big nose, little beard of the conservative Intellectual elite, 1950s era.)

here's another one : Wire Arrows = ><)))'> ( fishy )

Look'n for a home in Venice,Fla. ( and a Boat for the Inter-coastal waterways )

Bob Katz's picture

Dear Tony: Ahhh.. I do it for the love (mostly). By the way, that caricature is of me with long hair, a full beard and a pony tail, no crewcut, circa 24 years old and drawn decades ago by my artist-mother who decided to trim the beard for the art. Then as now I am a died-in-the-wool liberal/progressive who has contributed to Bernie this year. Well, enough of politics... . Until I can get through James Joyce at least once I will never profess to be an intellectual. :-).

tony's picture

so I looked him up, oh dear, an Irish! I wonder if I should add him to my loooooooong list of future readings.

You don't come off as a pointy headed intellectual, rather a pragmatist, as does our Bernie ( who is on one hell-of-a-roll just now) phew.

Doing it for Love?, I'm happy for you. It's a scarce commodity in my world.

Tony in New Hampshire but home soon.

Beagle's picture

It is always refreshing to read opinions and reviews by folks who have been in the trenches, who have made wonderful sounding recordings, and actually have something to reference against. Nice to have you here.

Bob Katz's picture

Thanks, Beagle. And I have the scars to prove it.

elfary's picture


What's your take on a mundane iPhone to drive in ear monitors or easy to drive (volume wise) ?

I have tried some AK stuff in the past but i would not say that they trump my iPhone driving a set of Shure SE846s.


Bob Katz's picture

Dear Effary: I regret that I have not gotten into in-ear buds so I can't answer your question, sorry. Those Shures have a great reputation but they are very user dependent I understand.

Dopaminer's picture

Just to clarify one point - the AK380 does not use ESS dac chips; it uses AsahiKasei chips.

bobajoul's picture

Maybe my vision is getting poorer with age but that headphone sure looks like the old design of the T5p from Tesla. They discontinued it a couple of years ago- is this a rework?

oleo's picture

Dear Bob, thank you for sharing so much wisdom! I love your articels. Now I investigated the new EQ on my AK320 and found something noteworthy.
I'm so interested in your opinion! Is this a modern way or pure s**t?

As far as I know, AK fixed the EQ with the latest FW. On my AK320, I think with the same DSP EQ "Engine" I made a strange measurement. It seems that the Q setting works very minimalistic. The results are deep ripples in the FR when using all kind of settings. I posted more details and an analyzer graph at http://www.head-fi.org/t/788296/the-ak320-thread/330#post_12381186

What do you think?

Kind Regards

tresaino's picture

Dear Bob,
coming in a bit late but just got the HA-2 and sounds indeed terrific, also with my Audeze LCD 3s. Thank you so much for this thorough review. I also enjoy Oppo's big brother HA-1 in my home system - planned to use it as headphone amp but it so good it also replaced my previous DAC. One toy less in the room, and more space for my analogue gears.
On another subject, please let me know if and how I can reach you for a PM.
Thanks, greetings from Brussels!