The AK100 is a rather remarkable little Digital Audio Player, more commonly referred to as a Portable Media Player.  AK_1004What makes it remarkable?  The claimed sound quality and the number of file types it supports plus the interface software used.  Before going into the sound quality part of the review, it’s first worth outlining some of the player’s credentials.

This is an all –singing, all dancing portable media player which supports not just the usual MP3/4a files, but also WAV files (16/44.1 files ripped from CD for example) and lossless FLAC as well as (and here’s the remarkable bit) studio quality 24/192KHz files.  Whilst availability of many of your favourite albums or tracks will be an issue at such high resolution, it’s there none the less.

Starting with the size, it’s very compact measuring just 59mm by 79mm tall by 14mm wide. It’s made in a smartly finished machined billet aluminium case with glass and plastic coverings finished in a gloss black and contains a refreshingly large 60mm user interface screen.  It comes equipped with a headphones/3.5 mini-jack to RCA output socket (doubles as an optical output with the right lead for an external DAC) and an optical input for connecting Toslink cables from a CD transport or hard drive.  There’s also a mini USB for computer connectivity/sync and charging the battery.  Annoyingly there is no AC power adaptor for charging the unit which I would have preferred to use during the review.

The unit also benefits from Bluetooth connectivity and whilst bandwidth is severely curtailed in Bluetooth mode, it does mean that you can connect via Bluetooth to your car stereo (where so equipped) and have perfectly acceptable quality music on the go.

Storage wise, the internal flash drive has a 32 Gig capacity and at the base of the unit there are slots to expand memory using a further two 32 Gig micro SD cards giving a none too shabby 96GB expanded memory.  We’ll see further on why this may sound sufficient but for some users will be a problem.

Disappointingly there are no headphones supplied as standard but since most folk usually prefer their own ‘phones, or already likely have a set, this shouldn’t pose too many problems.  For the review, I was sent a set of very nice Sennheisers, but also used my own in-ear ‘phones and my trusty Grado headphones.

Market Placement

Knowing what the little unit was, I started racking my brains to see what the main market for it is.  Now at this point I will AK_1002mention price because it’s a completely relevant point and should not be ignored.  Sitting comfortably?  Good, it’s just as well because the AK100 costs just shy of £570 in the UK.  No, that’s not a mis-print, the cost is indeed that of a very well specified CD player, integrated amplifier or even a reasonably good pair of loudspeakers.  Knowing the cost, it therefore seems reasonable to ask just who would buy the unit, and more importantly why?

Well knowing what the unit can provide and the cost, it seems logical that it isn’t meant as an upmarket portable audio player, more likely that it’s something intended to form the heart of an audio system, perhaps replacing a CDP and in doing so offering a higher resolution and more connectivity flexibility than a CDP can give, whilst at the same time benefiting the user by also being a portable device which can be used in the go, so all things to all people?  I did in fact speak with Michael Osborn of Air Audio (the company distributing the AK100 in the UK) about this point and he agreed that this was indeed the market placement for the device.  Think back a year or two to another device which was similarly specified, but flopped rather spectacularly on cost and styling, so have Astell & Kern got the balance right?  Time will tell.

Sound Quality

The unit arrived pre-loaded with several dozen albums ripped from CD.  Powering the unit on, I was pleasantly surprised to see that JRiver had been used to not only transfer album tracks but also full graphics, so album art appeared too.  The screen is touch-sensitive and the menu is very intuitive.  It wasn’t all perfect though.  I found that sometimes whilst scrolling through albums (by artist, media quality, track or album) the selection could be a little hit and miss and that a fairly precise technique needs to be adopted.  Also, whilst a track is playing, the display automatically switches itself off after a short while, presumably to save battery life, so you have to press the power button to reactivate the display.

The loaded albums varied in quality from 24/88 downwards, but that was sufficient to get a flavour for some of the hi-rez credentials and I was able to directly compare the Rolling Stones “Grrr” album as well as a few other artists (including the fabulous Amber Rubarth singing on her debut album “Sessions from the 17th Ward”) with my CDP as the source in a direct A/B comparison which was useful.

From the off, it became apparent that depending on your hifi set up or headphones used, a little tinkering with the inboard 5 band graphic equaliser is worthwhile.  Whilst a 5 band EQ is way too crude for any fine, fine-tuning, it certainly helps to establish a balance where things like room acoustics, loudspeaker response or even recording quality are concerned.  I found the EQ best left with a slight increase in bass and treble and left it at that.

Use with Headphones

Sound quality varied depending on the ‘phones used.  My favourite headphones with the unit were my Grados where the clarity, detail and low hiss from the ‘phones led to fatigue-free and very dynamic sound. Certainly in a par with the Hi-Sound DAP which I reviewed a while back.  I won’t dwell too much on how it sounded with headphones since ultimately, the sound you get will largely be determined by the appropriate choice of ‘phones, but with the CD’s ripped to file, it’s sufficient to say that the sound is far better than the average MP3 player.

Use with HIfi

This was the “main course” as far as I was concerned.  Having got used to the controls of the AK100, it was fast becoming a real pleasure to use.  Simply replace the headphone jack with a mini-jack to pair of RCAs cable, plug into a line level input on the back of your amp and you’re away.  I wanted to try this configuration as direct comparison with my CDP, a Consonance Mini Droplet.

Not only did the AK100 equip itself well by comparison but in some ways had a slight edge over the Droplet.  I was listening to exactly the same files from the same CD (“Grrr” album) but through the AK100 the album tracks sounded a little livelier with slightly better dynamics.  The difference wasn’t great, but it was there.  For a portable media player to perform so well against a CDP which cost £2K isn’t so much of a surprise these days as DAC technology has come on, and decent DAC’s can be had for modeAK_1003st outlays these days.  The DAC in the AK100 is a Wolfson BWM8740, a highly regarded and arguably a better DAC than used in the Droplet.

Comparing Amber Rubarth’s ”Storms Are on the Ocean” the AK100 gave more sense of space and of presence to the acoustic track and there was greater detail to the finer nuances of the voice, so 2:1 to the AK100.

To be honest, I stopped comparing it with the CDP after that is it had already proved that sound quality was very good even though the albums listened to were still way short of the ultimate resolution that this little unit is capable of.

If using it with a hifi system, it can also be used as a DAC so that instead of ripping your files, they can be played on your current CDP providing you have the option of an “optical out” function or it can be used as a source and played directly into a separate DAC providing that your DAC/amp has an “optical in” function.  In addition, an obvious place for it would be between high resolution media files stored on a laptop perhaps using the AK100 as the DAC to feed line level signal to your amp.  When using it as a source into the amp, the volume knob needs turning to maximum.  The volume control deserves a mention here.  It can be controlled via the touch sensitive screen or via the 150 step adjuster knob on the side of the unit.  I preferred to use the adjuster as it was less hit and miss in use and offered very fine control of the output. The screen can be a little fiddly to set precisely but I’m sure that’s also a matter of practice!

I had it plugged in for several days and the battery from fully charged lasted two and a bit days before the unit needed taking out and re-charging on the PC.  This is where it would have been useful to have an AC power adaptor to charge/power the unit rather than keep on having to lift it out to recharge it every few days.

Listening to some classical music, the dynamics stood out as being very good indeed and the listen was refreshingly fatigue free and left me wanting for more.

Unfortunately I did not get the opportunity to try this out as a stand alone DAC using an optical connection because my kit isn’t equipped with an optical connection.  However, in theory, the performance should be little different to using it as a source with downloaded Hi-Res files so I have no doubts that the AK100 would have performed just as well.  It is a shame in some ways though because I would have like to try some 24/192 files with it.


Whilst I very much enjoyed my time with the diminutive little AK100, there were several questions that kept on nagging me at the back of my mind, and in the spirit of honesty I will express my own views here.  I stress that these are my own personal views and that others may have a completely different outlook.AK_1001

Starting with some positives as that’s a nice place to start:  the build quality is good, robust and of reasonably high quality.  The software and user interface are nothing short of excellent and make this player a real gem in use.  I’d go as far as to say that the user interface and software are almost important as its high resolution credentials, because if the device is cumbersome or unsatisfactory in use then quite simply put, it would never get used and would be pretty pointless from that aspect alone.  The AK100 though is probably the very best portable media player that I’ve had the pleasure of using in this regard, so I have no doubt that it would get regular use in one other of it’s possible functions.  Sound quality is excellent and certainly up there with some very well specified CD players and stand alone DACs.

However (and there are a few of these) I come back to the things that are nagging me.  First off is the question “what does this do that a CDP or DAC doesn’t in relation to being at the heart of a hifi system?”  Well, besides the obvious “it plays very high res files very well” and has the capability for 24/196Khz files, ultimately the availability of such files are still fairly limited and its questionable despite some debate within audio circles whether a significant advantage can be had in listening between these files and a very well recorded CD. There are those that will say there is a difference (therefore an advantage) and those that will say they cannot hear the difference.  Personally, I see the best way of viewing it as the unit provides greater flexibility in file choice and if it can exploit such resolution, then that’s technological advancement and I embrace it as such.  Would I feel cheated if comparing it to the sound quality of CD? No, not at all.

The other “however” is that whilst in some ways it’s nice to think of all those 100s (1000’s for some) CD’s ripped and stored away in the attic as back-ups, the thought of sitting down, ripping and cataloguing my entire CD collection…well that’s simply not going to happen…life’s way too short. I find no problem with picking a CD up, inserting into the drawer of a CDP and pressing “play”.

Yet another “however” is that I also know that for slightly less than the cost of the AK100, I can already go out and buy a fully featured DAC, which although may not offer the ultimate high resolution, would do roughly the same job.  All I’d have to do is (again) rip my CD’s to my hard drive and connect my PC to the DAC, so again, I can’t see where the AK100 would fit in for me.

If I sound like I’m being picky, then the bottom line is it’s because of my own views on whether this could replace my CDP (and I’ve established that it won’t happen that way for my personal set of circumstances and preferences) but also because the cost has to be a factor.  £570 is a hell of a lot of money for a DAP, and the only way that I could partly (but never fully) justify spending that amount on this player was if I compare it with what it would cost for a CDP of equal quality, or more importantly for me, whether I see a need for the unit.

If my CDP went kaput tomorrow, then replacing it with an AK100 might start to make more sense.  Add to that, it can be unplugged and used as a personal music player, used in the car, or on holidays.  It could even be partnered with a little T-amp and some bookshelf speakers to be used as the source for a sound system you could have anywhere in the house when the mood takes you.  Problem here is that its credentials mean it needs to be taken more seriously than a piece of kit to satisfy mood music, especially when there are cheaper (much cheaper) alternatives for that.

There may be those out there who see this as just what they’ve been looking for, those who want to ditch the CDP or those who do in fact play with 24/192 files and perhaps use Pro-Tools HD or similar and would love to have one of these.  Bottom line is that if you can afford it and the money’s not an issue, then it is an excellent product, well designed, well made and which performs very well.

Whilst in theory you could ditch the CDP, if you have a large collection of CDs, then the 96GB is simply not going to be anywhere near enough memory.  You would have to have everything stored on a separate hard drive and every now and then, swap over files to change the menus of albums.  This would be way too restrictive for me because Murphy’s law states that the piece of music I want to listen to at such-and-such a point in time isn’t on the AK100, it’s on the hard drive, so I would end up ruing the day I got shot of my CDP.  In this respect there are already file storage (and streaming) devices that can hold 20,000 or more music tracks, and whilst more expensive than the AK100, if you are going to invest 6 months of your life transferring your entire collection to hard drive, then you may be willing to spend the extra to ensure its a one- time only job!



The Astell and Kern AK100 is a superb music player, with an excellent on board DAC and which offers myriad of connection choices allowing welcome flexibility in use.  The sound quality is up there with some seriously specified CDPs when used as a source and it has the ace up its sleeve of being capable of putting the best CDPs to shame on resolution should you have access to the files.  It is intuitive in use, and employs excellent software and for many people, would see regular use as a personal media player, a system source, and a fabulously specified DAC.

However, it is expensive for what it (physically) is, and I can’t help but think that it would be marked out as another milestone in audio development if only the price was low enough to persuade people that they don’t have to fully justify it as a replacement of a key part of their system, but as a welcome and a flexible addition to it.  There will be many for who cost isn’t an issue, and the unit’s quality and functionality will win the day for them.  A great many people will struggle I think to see exactly where it could fit in long-term as a mainstay part of the system given the limitations of run time between charges, limited file storage and the alternatives out there, not least the trend towards amplifiers with in-built DACs.

Having said that, the unit does everything that the makers claim, is a pleasure to use and provides fantastic sounding music.  You have to decide where it fits in, and if it does, then you may consider it money well spent.

In all honesty, whilst I regard this unit very highly for its superb sound quality credentials and its flexibility, I cannot (regrettably) ultimately put it forward for a HP “Recommended” label because I personally struggle with the whole issue of what it is trying to be and indeed with the bottom line of cost.  I would at least expect a full set of cables and some headphones at the cost and whatever way I try (objectively) to argue a slot for it in my own hifi system, I simply cannot see one ending up there.  Had it been priced more competitively (in line with an ipod classic for arguments sake), the AK100 would have been far easier to recommend.  To some, the price tag may not be an issue at all, so you have to make your own mind up on that particular point.  One thing’s for sure, the Astell and Kern AK100 is a marvel of miniaturisation, flexibility and audio sound quality.

Author – Paul

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  1. I thank Paul for such a thorough review, as the Distributor of the AK100, I have had a lot of time to spend with it, mostly traveling from Dealer to Dealer, selling the concept to them. Paul is right to point out that the AK100 will offer an outstanding musical performance in the home Hi-Fi, but I think its strengths lie in its flexibility. I have had numerous conversations with people who hanker after a portable player of high quality to use with their expensive travel headphones on the commuter train, or on plane journeys, or in the car. If you are not using it for personal use, then yes, perhaps the other options available offer a more specific solution, if you want both a portable studio quality player of high quality and can be plugged into the home Hi-Fi then there really is nothing else out there this portable, or of this quality, regardless of price. One further point to mention, that holds some of the ‘secret’ to this players sound quality – the output amp and buffer amp after the DAC are of very high quality indeed. Finally, mains USB chargers can be bought for a few pounds and yes, its a shame there is not one in the pack (you do get some Studio Quality music and a 32gb microSD card with the unit). Michael, Air Audio Distribution.

  2. Wonderful review Paul, however I would like to add to what Michael said in that I see this first and foremost as an incredibly high sound quality portable player, which has the added bonus of being easily connectable to a home system.

    I already listen to my music in Flac format, having ripped my cd collection and some of my vinyl, so this unit is a no brainer for me. I have also started purchasing music from hdtracks where albums can be purchased in full mastering quality.

    I would also like to mention that storage wise the AK100 can hold an awful lot more than the advertised 96gig. It will also accept 2 64gig cards if you format them to FAT first, providing a wopping 160gig, including the onboard 32gig.

    As you can tell, I’m very excited about getting my grubby little mits on one of these beauties. Just waiting on stock to come back into the UK :)

  3. Interesting and detailed review Paul.
    I think the target market for this little player will be people that appreciate high quality sound in their home system, but also want the portability in a ‘grab it and go’ fashion. If you travel a lot then I reckon this will be well worth the price tag for the ease of switching from your home to portable system with no compromise in sound quality.

  4. Thank you for your comments gentlemen. Yes, I would agree with you that having handled and listened to the unit, it is a great high quality portable system, but as mentioned in the review, my observations were personal, based on whether I could see a space for it within my system. You are right to point out that others may see this as what they’ve been waiting for from a portable unit and in terms of ease of use, it is without a doubt the best portable DAP that I have handled. If there are those that don’t mine the price tag and do travel a lot, then I am sure that this unit will suit them down to the ground.

    I suspect though that the market will be self limiting if this is considered only as a portable player. I think that the broader market might be as an addition to a home system but with the flexibility to use in the car or out for a walk. That is how I viewed the broader market anyway. It is a great little unit and without knocking it, I felt it fair to point out some of the limitations which no doubt apply to all such portable media players.

    Bottom line is that there is a lot to recommend in this unit. Prospective buyers are the only people who can really make a judgement on price. It either will be an issue or it won’t and time will tell. I wish you every success with it though Michael.

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