Astell&Kern A&ultima SP1000 portable audio player

People often ask me how I listen to music when I travel. I play MP3s on my iPhone.

That answer always surprises, and sometimes disappoints: "You listen to MP3s?"

The response is moderately tempered when I add that I use good in-ear monitors (IEMs)—either Westone ES50s (ca $995) or Jerry Harvey Audio Laylas (ca $2725), both with eartips made from molds of my ear canals.

Those multiple-balanced-armature IEMs perform incredibly well, and the custom eartips make seals that are measurably better at rejecting noise than the noise-canceling, over-ear phones worn by Bose-fanboy peacocks who show them off as they strut up and down airplane aisles.

Music's the main thing, not sound, especially in the air, and since just about every new LP I buy these days includes a card for an MP3 download, I put those files on the phone and I'm good to go.

But lately I've been thinking about better-sounding portable music than my phone can give me. For one thing, I find using iTunes unpleasant (and with each update, Apple makes it worse), and even my phone's 64GB of storage doesn't give me enough room for all the music and pictures I'd like to have on hand.


Before my last long plane trip—last June, from New York to LA, for the first Los Angeles Audio Show—I hurriedly added some new files to the phone and removed others. I could swear I hit Sync but there was some kind of glitch: I took my seat on the plane, opened iTunes, and my phone's record shelves were empty.

I was at LAAS to cover analog, but I also made sure to attend, with John Atkinson and Jana Dagdagan, Astell&Kern's press conference. The company's president, Owen Kwon, was there for the US debut of A&K's new flagship portable player, the A&ultima SP1000 ($3499). But better sound on the road must have been on my mind even before LA—last May, at High End in Munich, where the SP1000 made its world debut, I'd stopped by A&K's floor display and listened to it for longer than I could spare.

I'd heard an older A&K player through Stax electrostatic headphones a few years before, at a friend's, and hadn't been bowled over. Through the A&K, my friend's high-resolution files sounded distinctly better than the MP3s I'd been listening to through my phone, but a particular sonic character was audible with every file. Once I'd heard it, I couldn't not hear it, and I didn't like it.

In Munich, I listened to snatches of a dozen or so files through the A&ultima SP1000 and heard none of that character. I was primed. After learning more about the new player at LAAS, I was ready for a home listen. Kwon obliged.

Do I need a 32-bit-capable player with no recordings available at that bit depth. Can any portable audio player be worth $3499?

Exactly Who Are Astell&Kern?
Astell&Kern is a creation of the Korean company IRiver, Ltd., founded in 1999 by seven former Samsung employees who hoped to capitalize on the future of portable digital audio at the dawn of the MP3 devolution. Steve Jobs captured that market for Apple by integrating the iPod MP3 player with a virtual online music store, iTunes, leaving IRiver in the same lurch that makers of point-and-shoot cameras found themselves in when Jobs included a point-and-shoot in his Apple iPhone. Just as camera makers, to survive, were then forced to reinvent themselves as purveyors of high-quality, high-tech, high-resolution single-lens reflex cameras equipped with high-performance lenses and push quality on an "on the cheap" audience, IRiver has, with Astell&Kern, gone way upscale in build quality and performance, sonic and otherwise.

Simplicity Without, Riches Within
You'd expect a $3499 portable player to come in a deluxe package, and the A&ultima's SP1000's wooden box did not disappoint. More important, the SP1000 itself, available machined in stainless steel or copper, is a luxury item that seems to be finished to the highest jewelry standard. A battery charger isn't included, but you can use your computer, or the 5V charger that comes with an iPhone.

Weighing nearly a pound (135/8oz) and measuring about 5¼" long by 3" wide by 5/8" deep, the SP1000 is at the upper limit of what I consider "portable" in a player—but even in its leather case (included), it fits neatly in my shirt pocket. Most of the front panel is taken up by a 5", high-resolution (1280x760), LCD touchscreen. The SP1000 is turned on and off by pushing the generously sized, knurled knob that occupies a wedge-shaped gap machined out of the right edge of the thick metal case. This knob also turns the LED screen off and on, and spinning it adjusts the volume level, which can also be set by sliding a finger across the screen. The player booted up in less than a minute; its auto-shutdown feature can be set to turn it off after period of inactivity whose length is defined by the user, to save the battery charge.

Three small, circular buttons flush with the left edge control the Previous/Rewind, Next/Fast Forward, and Replay/Pause functions. On the bottom edge is a USB 3.0 Type C input for fast data transfer and charging, and a port for external devices; on the top edge are two minijacks (3.5mm headphone/optical and 2.5mm balanced out), and a slot for a microSD card of up to 256GB capacity; the SP1000 also has 256GB of built-in memory.

The SP1000's outward simplicity belies the versatility packed inside. The player supports playback of the AAC, AIFF, ALAC, APE, DFF, DSF, FLAC, MP3, OOG, WAV, WMA formats—and, for all I know, E-I-E-I-O. PCM sample rates range from 8 to 384kHz at 8, 16, 24, or 32 bit depth. DSD is supported up to 11.2MHz (DSD256).

Also included are 802.11 b/g/n WiFi (2.4GHz), v.4.1 Bluetooth (A2DP, AVRCP, aptX HD), multiband parametric equalization, over-the-air firmware upgradability, and integrated Tidal and Groovers+ streaming. Tidal and Groovers+ are the only stores currently supported, though in the future others may be. I'm not sure Groovers+ is available in the US, and I didn't try to use it. I think it came with the demo unit.


The AK Connect feature allows the SP1000, via Wi-Fi, to access and stream and/or download music files stored on computers on the same network, and play them back through speakers, A/V receivers, and/or other network-connected devices. This requires downloading to your computer from A&K's website the MQS Streaming Server software (not to be confused with MQA).

Another built-in feature (USB DAC) allows the SP1000 to be recognized as a soundcard by a Windows or Mac computer. Music stored on the computer can then be played through the SP1000's headphone jack. The USB function also allows the SP1000 to be connected to a portable USB DAC with a special USB-C cable (not included).

In theory, CDs can be ripped directly to the SP1000 using an optional A&K CD ripper, but at the time of writing this was described on the A&K website as "sold out," with no price listed. I never got to try one.

Packed inside the A&ultima SP1000 are an Octa-core CPU, an AKM AK4497EQ dual DAC, and a VCXO Reference clock. A&K's specifications include: a signal/noise ratio of 120dB at 1kHz (unbalanced) and 122dB at 1kHz (balanced); THD+noise of 0.0005% at 1kHz (unbalanced) and 0.0008% at 1kHz (balanced); and clock jitter of 30 picoseconds (typical) or 200 femtoseconds (VCXO Reference clock).

IRiver Ltd.
US: Astell&Kern
39 Peters Canyon Road
Irvine, CA 92606

Richardharmer's picture

At this price and quality some may buy this to use as a solution for at-home listening through ones home system as well as using it on the go. Perhaps this duel use could justify the price? Could it offer a better solution than a stand alone server/DAC and portable player for the same total budget?

dalethorn's picture

I would use it as the core of a home system, except that I'd have to make sure it's not constantly charging the battery when plugged into the AC mains.

mrkaic's picture

1. The machine looks heavy. Is that useful in a portable player?
2. At this price I would expect perfection. What is the issue with that clipping into 300 Ohm and behavior at 96hHz?
3. How does it compare to LG V30?
4. Are there any cheaper alternatives?

tonykaz's picture

we needed 3 Devices to do what these AK players do.

The AK240 is pretty much the ultimate travel rig.

This new AK is better but I'm not clear as to why.

Still, the darn thing is cheap compared to anything in High-End and it doesn't have a Monthy Subscription Rate like an iPhone so it's Pay-Once sort of thing.

Well, how long is it's service life?, we should know that sort of thing, shouldn't we? Sony Walkman stuff lasts 4evvvvvvvah. Will these AK devices end up in the dead drawer with all those little electronic things we no longer use? or is there a 'deep' support system established and if so, where is it and just how do we access it?

What about those Batteries?, who replaces them when they won't take a charge?, that will affect ReSale Values and Trade-in Residuals, won't it?

There's lots of 'what about' questions that need answers when it comes to much of this Asian stuff, it starts to matter as prices increase beyond the cheap price of a eBay Chinese digital pedometers.

Sony had a Service Center here in Michigan that they closed a looooooong time ago. Now, if an Asian device needs service we end up looking for a local lad with our fingers crossed. Phew.

Expensive Asian Electronics is 'Risky Business'

So, the decision on a $3,500 Asian gizmo is a matter of Disposable Income: Can we afford to loose our investment?

Some Asian stuff has superb support: KIA, Samsung, Nikon, Cannon and quite a few others but not everything by a long shot.

Astel & Kern is the highest end of high end travel gear for music lovers. I think it could replace everyone's music source with the possible exception of a died-in-the-wool Vinyl guy or a guy like me that has an iMac as my Big Base System.

But, the Smart Phone is just around the Corner and coming fast. One Smart Phone already has a quad DAC. So, these beautiful Astel players seem to be on borrowed time.

Here comes iPhone 9

Tony in Michigan

ps. Quincy Jones showed me Electrocompaniet

Mihalis's picture

True, MQA capable phones/portable DACs can soon move aside the storage and retrieval function of these players. However, arguably, the electric storm that is a phone will not be able to compete at the ultimate level with dedicated players. Possibly irrelevant when travel and flight noises are a nuisance.

tonykaz's picture

I more than 'mostly' agree with you.

These AK players are much greater than 'this' review experience reveals.

Overall, I'd say, this Analog Planet guy has just given ( his loyal following ) permission to buy, own and enjoy this cute little $3,500 digital player. hmm It's a 3rd. Generation music format device.

Which seems to be the point behind this interesting personal story : 'Analog Planet' is recommending Digital Players now. Who could've predicted this outcome?, of course, it's a toy compared to anything Analog, where prices for serious gear begin at twice the measly price of the AK.

Anyone that can find happiness with an AK player should consider themselves lucky not be burdened with having to manage a vault filled with pristine vinyl, hundreds of thousands of dollars in playback gear and the general disapproval of family members who probably consider the vinyl guy a 'crazy' uncle sort of person. ( which might or might not be the case ).

The 4th. Generation Format is where we play our music on our Smart Phone and we Rent our music from Tidal or some other outfit.

What the 5th Generation will look like will be fun guesswork for the next 25 years.

Tony in Michigan

ps. I've lived in all 4 Generations of music formats and I'm pleased with this 3rd. Generation and it's playback gear. The full implementation of the 4th Generation Format seems too good to be true.

dalethorn's picture

"The 4th. Generation Format is where we play our music on our Smart Phone and we Rent our music from Tidal or some other outfit."

They've been saying that about the Cloud (or whatever they call the latest "we provide the best uptime" service) since before the Internet, when IT services were provided by Big Blue and others. There will never be a streaming service so reliable that I can depend on it 100 percent, during the critical 90 minutes I have between missions where I can listen to my favorite symphony uninterrupted.

tonykaz's picture

it's still the 4th.

I hope they make it reliable and universally useful.

We'll still have old geezers like me collecting the hell out of CDs and loving the playback on the latest Oppo.

I hope the 4th becomes a smashing success for all involved, I'd love to have unlimited access to all the music ever recorded.

preferably for free or less with a lifetime subscription to room and Tidal.

Tony in Michigan

dalethorn's picture

Old geezers like me will have a 5-10 terabyte Sandisk flash drive, size 2x2x0.5 inches in my wallet, with tens of thousands of music and video tracks at my fingertips for instant lookup and playback.

I have hundreds of tracks that will likely never be on the streaming services, or if any of them are, they'll be nearly impossible to find (read: time consuming).

When you really think about all of the show-stoppers between you and some specific but not easily accessible tracks you want to hear, you'll be saying "Well, I didn't need to hear that anyway - lots of other things to listen to."

And it's not that you *have* to hear what you want, nor is it that other good things aren't available - the simple fact is that there are consequences to giving up control of your music, and you should be honest and acknowledge those consequences.

tonykaz's picture

Sure, 5-10 terabytes.

I have all my music on memory.

But, there's plenty of interesting music out there to explore.

Still, I don't know how much time i have left, I'm having another Ct Scan Nov 7th. I could get bad news at any time.

On Sony: I had a few un-repared SONY ProVideo pieces. I was mostly referring to Garage Sale Walkman stuff. Of course everything, even Motorola & vintage Western Electric stuff can and does break, nothing is immune to failures. ( except the loyalty of Trumpeters )

Tony in Michigan

dalethorn's picture

I hope your scan goes OK - I've had so many scans that they killed all the bugs in my system. I don't know how many Trumpeters you know, but I always played Cornet myself. And BTW, we've decided that the current administration will continue forever through inheritance, much like a good universal music format that doesn't need to be replaced. And that's the name of that tune.

Michael Fremer's picture

The scans obviously missed a few bugs

dalethorn's picture

Funny thing - I have several friends who thought the 'maga' thing was a scam - not needed. But then a few weeks later they're talking about our "empire in decline". Could be my friends fell into the quantum rabbit hole, and still think 2 plus 2 equals 3.

Michael Fremer's picture

Please take some antacid and call your gastroenterologist in the morning. The review was not intended to give anyone "permission" to buy this player. It is not a "toy". No one considers me a "crazy" uncle sort of person. However you sound unhinged. There's no apostrophe in "its playback gear". Not sure who to whom the "we" refers in your post. "Crazy" people usually address imaginary people like that. I've used this player on airplanes, at the gym, at the pool etc. It's filled with 96/24 vinyl rips that sound better than any downloaded files or streamed on TIDAL files, though I appreciate TIDAL a great deal as a means to buy new vinyl.

tonykaz's picture

"Unhinged" ?

You may be right, back then ( about one year ago ) I was undergoing a Second Cancer Screening to confirm. My older twin brother just died of Brain Tumors. So-far, I'm clear but have to keep a close watch for active killers.

I'm scared for the first time in my looooooong life. I might be acting out my fears.

Tony in Michigan

dalethorn's picture

"Sony Walkman stuff lasts 4evvvvvvvah."

Well, no. I had a couple of Sony WMD6C's that were practically indestructable, and a couple of reliable Sony TVs in the 1970's. Of the thirty other Sony handheld products I've had, all failed within 3 months. The VAIO computer ($2500) was a joke - the only service center available to me (I was in Irvine CA) was a fly-by-night outfit in Florida, which put the wrong O/S on it, then after 6 weeks when they returned it, it failed permanently.

Not to mention the handheld digital recorder ($800) I bought circa 1992, which used Sony camcorder batteries as I remember. Both the original battery and a genuine Sony backup battery I bought ($110 each) failed after about 3 charges.

tonykaz's picture

well then, phew.

Garage sales have Sony stuff, it always seems to work.


I'll accept that my experiences are different.

Tony in Michigan

dalethorn's picture

It's arguable that your experiences in product failure are different, but if you had the defective Vaio in So. California, your experience with Sony service would NOT have been different.


he said Walkmans ... not TVs or computers.

dalethorn's picture

As I'm sure I said already, my Sony handheld products had a more than 90 percent failure rate within the first 3 months. The only reliable Walkmans I found were the D6C's. The *primary* gripe I had against the tiny computer wasn't the failure anyway, it was the scam "service". The other failures I either returned or tossed.


I'm pretty sure you said that already.

Mihalis's picture

“You were expecting something else?” Yeah, I was. I was hoping that the respected Mikey would respect himself and those of us who have spent time to also learn the portable format with a professional review of the standard of his analogue corner.

Zero absolute experience? Check. No relative benchmarks? Check. New associated equipment? Check. Focus on headphones instead of the player? Check.

An Iphone user phoning in his review. Then again, I did learn that a larger, heavier object balances better on the airplane table during turbulence. Duh.

Mikey you are literally the last reviewer that I read. Please don't take that away from me!

Now on the players:
(1) In the same way that the AK240 was bested by the 380, this new player is a further step towards the AK evolution and house sound.
(2) It is significantly more powerful and the control of headphones is greater, solid and noticeable.
(3) There is an increase in soundstage, especially horizontally.
(4) The player continues to not be the quietest thing around (the Sony beats it handily there) but it is more "airy" and as such still quite engaging.

Richardharmer: you would need to be specific about which comparison you seek. I can say that for headphones, paired with a good amp, it can be the base of a very high end system. Otherwise I dont know.

mrkaic: it is heavy like the Sony. Both companies will claim that is necessary for isolation and sound quality. They both feel great. I wouldn't want either in my pocket unless it is a jacket. But you can survive an hour at the airport before sitting down on the plane. Compared to the LG? It blows it out of the water. These are not comparable devices. Yes there are tons of alternatives from AK, Sony, Fiio, iBasso, HiFiMan, Onkyo, Pioneer, Questyle, Pono, etc. Some would in fact argue that buying a less expensive player and pairing it with a great portable amp like Vorzuge's offerings (or Chord etc) may be a better overall idea for performance.

tonykaz: I respectfully disagree. The Sony gold is indeed regarded as the best player (as can be seen by its dominance of shows lately) but obviously one can very reasonably argue against that (what is "best" anyway.) I am a lot less worried about reliability as the quality of these devices has proven to be excellent. Whether AK survives as a brand is another issue/question. But for those starting up, I would look for used equipment where the initial 30% discount is already gone.

Michael Fremer's picture

I'll stop reviewing portable players. I had to start somewhere. You've given me the incentive to stop. I don't need to take shit from anyone at this point in my reviewing career so I will not explore this subject any further.

lothlorien's picture

Hi Michael...I have been following your online videos, reviews, comments etc for a couple of years now. I am a planetary scientist with some expertise in a number of areas, but I can safely say that the #1 expertise I have acquired over time is to know when a person might know a thing or two more than I do about a subject and maybe listen and learn. After reading all the comments above, I felt compelled to join the site and ask that you continue to review "outside the box" (not just digital players!). I think it's great you that you happened by a product that you didn't expect to review, but tried it, found it worthwhile, and related the experience to the rest of us. Anyone who follows your reviews know that you are not afraid to say if a thing is shite or not, and that you are always very careful to give qualifiers and caveats where needed when expressing a subjective opinion (which you assume full responsibilty for). In the final analysis, opinions aside, I have always found your reviews to be informative and insightful based on your experience, which is why I continue to follow your reviews! That you expect us to not be rude in considering your learned and experienced opinion is hardly a lot to ask. I am sure I speak for a lot of readers when I say that the enjoyment of my audiophile hobby has only been enriched by your reviews over time. Of course, "Analog Planet" is mainly about all things analogue, but it's always refreshing when you aren't "prescriptionist" and venture "outside the box" in giving us useful and insightful comparisons of the analogue and digital worlds where appropriate. With candor I can also say that for my part, I really enjoy the slight irreverence and cheekiness that is part of your cache. And your insistence that folks employ a modicum of common sense and critical reasoning in following your reviews. Many thanks and I hope your reconsider your position regarding reviewing "outside the box". After all, that is usually where all the interesting stuff and fun is!

Best regards,

Chris Parkinson

valius55's picture

3500 Euros and portable ? No, thank you. I am happy with my opus 2, which is not the cheapest DAP too, but I would never invest more into a portable player


I got a refurb SanDisc portable for $30 and listen to it via a Grado SR60. And I'll bet dollars to donuts that you can't hear a difference. Prove me wrong ... and tell my why.

Plus, it firmly clips onto my clothing ... which your $3500 player is incapable of doing.

And a Sony portable CD player if I don't want to do any transferring. Not perfection, but it's good enough, y'know?

spacehound's picture

This 3000 dollar plus A&K can't do anything that a cheap Android phone, the 10 dollar Onkyo HD player app, a plug in micro or nano memory card, (for which most Android phones now have one or two slots), and a Chord Mojo can't do at an equal or possibly better quality, lower weight, and no bigger (even though it is 'two box').

And you can make phone call on that too :)