Review: Astell&Kern SR15 – Pocket Pleasure

Astell&Kern SR15

The A&norma SR15 is Astell&Kern’s latest entry level DAP and the spiritual successor of the AK70 MK2. Today we’ll find out how it performs.

Disclaimer: Astell&Kern provided the SR15 for this review at no cost. It is a loaner and will be returned to Astell&Kern. AK is not a site advertiser and in no way affiliated with Headfonia. Many thanks for the opportunity to review the SR15.

About Astell&Kern:

Astell&Kern is a South Korean high end brand for digital audio players (DAPs). Astell&Kern is a branch of Korea’s iRiver, which actually is the first company to ever build a portable audio player. Astell&Kern was launched with the mission to offer the absolute best where money is no object. Ever since their launch, they have redefined what is possible from portable devices. With the AK100 they introduced their first product in 2013 under the A&K brand.

Astell&Kern has pioneered a few things we know of today. They were the first to build a DAP with two DAC chips inside – AK120. AK was the first brand ever to introduce native DSD playback in a portable device – AK240. The AK380 was the first ever digital audio player that came with a Parametric Equalizer.

Just recently AK has introduced what they call Teraton. This is an audio module that contains their digital and analogue design. This module can be implemented by third party brands in order to get closer to the AK sound. The first product has already been released that utilizes Teraton – the Activo CT10.

AK also cooperates with many other industry leading brands. In partnership with brands like Beyerdynamic, Final Audio, Jerry Harvey Audio or Crystal Cable, Astell&kern has brought out many different products under their name. Together with JH Audio they have released a good number of different universal In Ear Monitors. Just recently we have reviewed one of said creations – the Billie Jean.

Astell&Kern SR15

Astell&Kern SR15

About A&norma SR15:

Astell&Kern splits their DAP portfolio in three lines. The over-achieving, luxurious A&ultima, the less expensive and high performing A&futura and the accessible entry level A&norma line. The SR15 sits firmly in the norma line, as a matter of fact, it’s the only unit in there currently. The SR15 is regarded as Astell&Kern’s cheapest audio player and comes with a price tag of 699 USD.

It features a dual mono construction with two CS43198 DAC chips. AK is well known for their balanced output implementation. They have always used a 2.5mm headphone port, if you think of it, they were the ones who made balanced outputs popular in DAPs. The SR15 has an internal memory of 64 GB, which is about double their competition usually offers at that price. If they offer any memory at all. On top, you can also put in a micro SD card to have even more memory. As far as I know there is no size limitation for the external storage.

When you connect your SR15 to your PC or Laptop it registers as an Android device using the Media Transfer Protocol. For Windows machines that’s no biggie, but if you’re a Mac user, this might cause you some headache. There are a number of programs available which make your AK accessible then, like Android File Transfer (Freeware) or Commander One. The MTP protocol also is limited in actions, so you shouldn’t transfer files and play from the SR15 at the same time. This might damage the files. This has actually happened to me when I had my AK380 a while back.

With the SR15 you will get a 24/192 capable audio player. It does play DSD files up to 128 as well, but downsamples DSD128 to PCM sample rates. DSD64 is handled natively. It plays pretty much any format except for ISO and MQA. I know many people would like to see MQA support too, and from what I’ve heard AK seems to be working on an implementation. Personally, I am not a fan of MQA for a number of reasons, but I can see why people would like to see it supported, as it does have benefits when it comes to streaming.

Astell&Kern SR15

Astell&Kern SR15

When we look at the specifications of the SR15 we will see, that it has a 3.3” TFT touch display. The unit itself has a good form factor for my taste. It measures 57.5 x 99.7 x 16.1 mm (WHD). It is not too big to carry around and it has a good weight. Coming from the SP1000, which has a 5” screen, I found myself accustomed to the smaller size very fast. Sure, there is quite a difference in font size but you get used to that.

The SR15 packs WiFi, Bluetooth (aptX HD), a 3.5mm and a balanced 2.5mm output. The output impedances vary slightly from 1.1 Ohm (3.5mm) to 1.6 Ohm (2.5mm). These are still relatively low impedances and should make no problems when using multi driver IEMs.

Astell&Kern’s DAPs can also be used as USB DACs. All you have to do is enable the function in the settings menu and connect it to your PC (drivers required). I have not tried this function myself as I used the SR15 purely as DAP on the go. Another function AK has given their products is the option to use them as digital transports. The SR15’s micro USB port can be used as an output to external D/A converters. This does work well with the Mojo and Hugo2.

What most people don’t know, or miss, is the fact that each WiFi enabled AK DAP can also be used as an UPnP endpoint (Renderer). This means you can access your SR15 (or any other AK DAP for that matter) with your smartphone, tablet or PC. AK provides for this purpose an App called “AK Connect”, which runs on iOS and Android devices, but also on the AK DAP itself (pre-installed). With this App, you have access to all network attached storages in your network. This works pretty well.

The SR15 also brings a number of streaming services to the table. There of course is a native implementation of TIDAL, but also Groovers+. Depending on your location, there might be more. AK also just announced that they will support side-loading APK files to offer support for more streaming services (such as Spotify, Qobuz, Deezer, …) with a future firmware update. This then also enables you to download files for offline listening.

The A&norma SR15 has a battery capacity of 3150 mAh, which holds a charge for about nine to ten hours. Depending on the type of files you’re listening to and what headphones you’re using.
A detailed list of specifications can be found here:

https://us.astellnkern.com/products/a-norma-sr15

The review continues on page two.

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A daytime code monkey with a passion for audio and his kids, Linus tends to look at gear with a technical approach, trying to understand why certain things sound the way they do. When there is no music around, Linus goes the extra mile and annoys the hell out of his colleagues with low level beatboxing.

    38 Comments

    • Reply October 30, 2018

      Booker

      Great review. It’s interesting that AK decided to downsample DSD to PCM, as the DAC chip is capable of DSD. I always wondered if it depends on the processor too – needing more computing power to feed a DSD track into the DAC chip?

      A few questions/comments:
      * Does gapless work well?
      * I’d love to know if there’s any delay on the USB DAC function, but I note you hadn’t tried it out
      * I know Nathan did the ZX300 review, but are you able to do any comparisons of SR15 vs ZX300

      • Reply October 30, 2018

        Linus

        Hi Booker,

        thanks for your comment.
        I think it is a limitation of the CPU to downsample.
        Gapless works well here, I mostly played FLAC files of multiple resolutions.
        Yes, Nathan did the ZX300, and he loves it. I too would like to know how they compare, but sadly I have no access to a ZX300, if I get the chance to compare them, I will, but they rarely pop up in the classifieds…

        I’ll try the USB DAC function and let you know. I still have it for about a week or so, that should be enough time to try it out with a YouTube video.

        Cheers!

        • Reply November 1, 2018

          Booker

          Thank you! I read in the AK70 review here that gapless didn’t work to well, so glad there’s improvements on the newer model.

      • Reply October 30, 2018

        Eykxas

        Only DSD128 and DSD256 are downsampled, DSD64 is play natively.

        • Reply October 30, 2018

          Linus

          Hi Eykxas,

          thanks for the info, indeed you’re right. DSD64 is handled natively while DSD128 is downsampled to PCM according to their spec sheet. Must have missed that one.

          Cheers

        • Reply November 1, 2018

          Booker

          Right you are. I see on the Cirrus Logic website that the DAC chip does support up to DSD256: https://www.cirrus.com/products/cs43198/

    • Reply October 30, 2018

      Daniel

      Thanks Linus. Nice review as always. And the photo showing the back of the player is simply gorgeous!

      I would love to see some comparisons with Sony ZX300, but only to find out that the Sony player belongs to Nathan..

      • Reply October 30, 2018

        Linus

        Hi Daniel,

        thanks for your comment.
        That was a lucky shot, but it turned out very well.

        I’d love to know how the SR15 compares to the ZX300, but the Sony seems out of reach for me. If one turns up on the classifieds for a good price I might snag it. 🙂

        Cheers!

    • Reply October 30, 2018

      Carl Marchione

      Hi ,I just purchased the AK70 MKII and want to know how it comapares to it …. Thanks

      • Reply October 30, 2018

        Linus

        Hello Carl,

        it’s in the review, page 4 😉

        “It has been a little while since I had the AK70 MK2, and I usually am not a fan of making comparisons based on memory, but I think many people are interested in learning the differences between them. Please take the following with a grain of salt. The SR15 has higher clarity in its sound, throws a wider and deeper sound stage and generally improved in terms of resolution and instrumental separation.”

      • Reply October 30, 2018

        Linus

        Oh, and you will not get the Open APK feature with the AK70ii as far as I know. So that’s a bonus for the SR15 right there.

    • Reply October 30, 2018

      Raghava

      How does this compare with X7 Mark 2?

      • Reply October 30, 2018

        Linus

        Hi Raghava,

        can’t say, I have never heard the X7ii.
        Sorry.

        • Reply October 30, 2018

          Lieven

          That one has even better clarity and a more neutral tuning

        • Reply April 25, 2019

          Luis André Ferreira

          Great review!
          I currently have ak70 (1st generation) paired with Custom Art Fibae2.
          I love my monitors signature and would love to upgrade my portable source.
          I like an engaging, full bodied musical source but not on the expense of resolution.
          I like ak70 signature but sometimes I miss some more refinement and instrument separation.
          Any advise between sr15 or se100?
          Thank you so much!!

    • Reply November 2, 2018

      Martin

      The last photo on page 4 is not showing the SR15. That should be the SE100.

      • Reply November 2, 2018

        Linus

        I know, that’s why I wrote this: “The above photo shows the A&futura SE100, I tried taking a few shots of the SR15 running TIDAL and Bandcamp, but my phone doesn’t seem suitable for nice photos. Or it’s me. It’s probably me…”

        😉

    • Reply December 23, 2018

      Steven

      Hope I am not too late to the party here.
      I have been an original A&K100 MK1 owner for many years and very pleased with it – would this be much of an upgrade sonically?
      And do A&K do proper shuffle these days as they certainly didn’t with the 100 MK1?

    • Reply January 25, 2019

      Matt

      “Astell&Kern is a branch of Korea’s iRiver, which actually is the first company to ever build a portable audio player. ” – how can this be true if the iriver was founded in 1999 and there were daps commercialy available in 1998 like MPMan, Audible player and Diamond Rio? The first ever built but not commercialy available was called IXI built by Rober Kramer in 1979.

      • Reply January 27, 2019

        Linus

        Hi Matt,
        thanks for your comment.
        I, obviously, always was under the impression of iRiver being first. Guess you’ll never stop learning new things. Thanks for the info!
        Have a great Sunday.

    • Reply January 27, 2019

      chema gonzalvo

      Great review Linus!
      I would like to know if you remember that the streaming apps (qobuz for instance) could storage music in the sr15 in order to listen to it when the device is offline. Thanks.

      • Reply January 27, 2019

        Linus

        Thanks for your comment.
        I don’t have the SR15 anymore to check, but all my other AK players can store Tidal offline tracks to play without network, so I’d be surprised if the SR15 would do it differently.

    • Reply February 1, 2019

      Shane

      How does this compare to the HiBy r6?

    • Reply February 27, 2019

      bibi

      Hi, thx for the review.

      I’m currently using Cayin n5ii DAP. I really appreciate how it sounds but I dislike UI, screen and responsiveness.

      Not sure that I want to spend money for the SR15 to just fix ergonomic details, but how does it compare to the Cayin n5ii on sound ?

      Regards,

      • Reply March 2, 2019

        Linus

        Hi Bibi,
        thanks for your comment.
        Wish I could help you there, but I have never heard the N5ii. Sorry.

    • Reply March 25, 2019

      Eli Segal

      Can you tell how does it stand against the ak120ii?
      If I’ll replace my 120ii with the sr15 , will I loose something?

      thanks!

      • Reply March 27, 2019

        Linus

        Hi Eli,
        thanks for your comment.

        Ah, the AK120ii, one of my all time loves. I regret selling it a lot actually.
        I’d still put the AK120ii over the SR15 sound wise, it’s more refined and open with a closer to neutral signature. It’s also super compact and I adore the simple design of it.
        One thing you’d gain with the SR15 is support for third party apps. You can’t install Spotify for example on the 120ii. The UI of the SR15 is also nicer in my opinion, though the 120ii also has the well thought out AK software… so you’re not really losing here with it. Just side stepping. 🙂

        Hope that helps.

        • Reply March 30, 2019

          Eli Segal

          Actually that helps a lot as I also adore the sound of the ak120ii
          But, I do miss a proper streaming software in it.
          What are your thoughts about going the r6pro route? is it better than the sr15 sound wise?

          thanks!
          Eli

          • Reply March 30, 2019

            Linus

            Hi Eli,
            if that’s your concern, then you might want to consider the SR15. You can side-load APK files to it and install Spotify for example.
            The R6 Pro is supposed to be very nice, but I haven’t heard it. I know Lieven is quite impressed by it.
            Hope that helps.
            Cheers

          • Reply September 2, 2019

            Eric Degis

            Have both. I think the r6pro may sound slightly more holographic via balanced but honestly I use the sr15 mostly now as the sound is excellent and the portability is amazing. Love the r6pro but it is a brick!

    • Reply April 25, 2019

      Luis André Ferreira

      Great review!
      I currently have ak70 (1st generation) paired with Custom Art Fibae2.
      I love my monitors signature and would love to upgrade my portable source.
      I like an engaging, full bodied musical source but not on the expense of resolution.
      I like ak70 signature but sometimes I miss some more refinement and instrument separation.
      Any advise between sr15 or se100?
      Thank you so much!

      • Reply May 3, 2019

        Linus

        Hi Luis,
        thanks for your comment, much appreciated.
        Sorry for the late response.
        I personally would take the SR15, I’m not the biggest fan of the SE100. Yes it’s better on technical levels, but it just doesn’t convince me enough to justify the pricegap between the SR15 and it. The SR on the other hand is excellent, and on the go it is my top recommendation at that price.
        Hope that helps.

    • Reply May 11, 2019

      Alex

      I found the gapless to be terrible with high resolution flacs. It’s fine with 16-bit stuff though, but yeah, I’m a tad disappointed with my SR15. I find it lacking in basic stuff, like shuffle play and continuous playback. It doesn’t play the next album it just stalls all the time.

    • Reply May 14, 2019

      MC

      Will Xelento be a good match to SR15?

    • Reply June 17, 2019

      Alessandro Sabatino

      The thing I would like to say is just the fact that in addition to inserting an equalizer, they could include in a future update a simple adjustment of bass and treble, without other various frequencies that do not need much

    • Reply July 30, 2019

      Alessandro Sabatino

      Ultima domanda, dal mio AK SR15 al Cowon PL farò un salto di qualità? Ho visto però che però il COwon ha un’uscita bilanciata da 4.4 mentre io ho tutti i cavi bilanciati da 2.2, è un problema. Mi da un suo consiglio? Vale la pena spendere 1700? Mi da un suo consiglio? Grazie

    • Reply September 6, 2019

      Jesus

      Great review my fiend, i have questions who’s best??? This A&Norma or Cowon Plenue R ??? And this combination is good A&Norma and EarSonics Es5 or Noble Dulce bass or ACOUSTUNE HS670cu????

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