Astell & Kern SR15 A&norma Review

There’s a 30-year-old photograph of me somewhere, where now I do not know, sporting a Public Enemy tour t-shirt, with a Sony Walkman in one hand and a pair of Sony foamie headphones peeking out from under a toque.

I listened to music through that Walkman and those headphones constantly for a couple of years – I’d listen while snowboarding, skateboarding, mountain bike riding, while on the bus, and most assuredly while doing chores.

That combo was an integral part of my daily life and helped me to parse every bit of musical and lyrical information from every rap, hip hop, rock, jazz and classical album I’d committed to magnetic tape in the mixes I was known to toil over for days before throwing down the $15 that a blank Sony ‘Metal Master’ ceramic cassette cost at the time.

Fast forward to the last several months and you can swap the Walkman for the Astell&Kern SR15 A&norma dual-DAC digital audio player, the Sony foamies for Audeze iSine 20 planar-magnetic IEMs and the cassettes for TIDAL or Qobuz.

At $699 USD for the A&norma, it is the company’s entry-level DAP offering, but don’t let that make you think its light on features – it ain’t.

Build and features

When it was time to refresh their product lines a couple years ago, engineers at A&K decided they needed to stuff as much user-friendly, future-proof tech as possible into even their most basic model – the SR15. A decision that when one looks at what the unit is comprised of electronically in a sub-$700 offering, you could be forgiven for not believing what you get for the money. Especially when you take into account the level of fit and finish on the A&norma.

According to the company the design of the “A&norma SR15 was inspired by a composition of interconnected rectangles,” and that ethos is evident holding the SR15 in your hand. The myriad angles and lines of the glass and aluminum alloy chassis imbue a feeling of absolute solidity like a precision timepiece of the Rolex strata – especially the ‘winding mechanism’ that doubles for volume control instead of using the screen – albeit one that measures 2.26 x 3.92 x 0.63-inch and weighs 5.43 ounces. It’s compact, weighty, and is possessed of millimetric perfection in its build execution. The 3.3-inch WVGA (480x800 pixel) screen is bright, crisp and surprisingly easy to navigate and type on even with my fat Caucasian fingers. Headphone output is twofold with wires, via 3.5mm unbalanced (2.0Vrms, 1.1 Ohm) or 2.5mm Balanced Out (4.0Vrms, 1.6 Ohm, only 4-Pole supported).  But wait, there’s more. Have wireless headphones? How about Bluetooth support via aptX and aptX HD wireless. AptX HD allows streaming of high-resolution files up to 24-bit/48kHz, giving users the best of a wired and wireless world in digital audio. There is a USB Micro-B input on the bottom for charging, or it can be used as a pre-amp to output digital audio to a home system, and does duty for PC/Mac data transfers (I used Android File Transfer for both music files and the APK for installing Qobuz, which worked quickly, easily – flawlessly). Built-in Wi-Fi is 802.11 b/g/n at 2.4GHz with remote/download firmware updates enabled.

Internally, the DAC and circuit architecture are courtesy of Cirrus Logic, which has been in the semiconductor business since 1984, and is a company known for high-quality, lower-cost chipsets. The SR15 has two CS43198 MasterHIFI-tier DAC chipsets – a designation only given to their chipsets that meet their highest audio performance standard, and according to A&K this is “… the first time [the CS43198 has been used] in a portable system.” The CS quad-core CPU allows up to 24-bit/192kHz bit-for-bit PCM processing. For 32-bit/384kHz audio – studio masters for example – downsampling is performed by the Sample Rate Converter to 24-bit/192kHz. For 32-bit/352kHz, it is downsampled to 24-bit/176kHz, with native bit-for-bit playback of up to DSD64. DSD128 is converted via DSD-to-PCM to PCM 24-bit/176kHz. Supported audio formats include MQA, WAV, FLAC, ALAC, AIFF, DFF, DSF, WMA, OGG, APE, AAC and MP3. The battery is a Li-Polymer 3.15mAh, 3.7V model which lasts a long time. In real-world usage of about an hour or so a day, the SR15 could go seven to 10 days between charges. Storage consists of 64GB internal Flash memory which can be expanded by 2TB via microSD.

Listening sessions

I used the Audeze iSine 20 for most of my listening, which I felt was an ideal partner for everyday use, but the SR15 had no issues driving high-efficiency cans like the Audeze LCD-4z or HIFIMAN HE1000se. Ditto a pair of Beats Solo 3 Wireless. I will say, that through the more revealing big over-ear models, there wasn’t the same bass depth, timbral color and transient speed I’m used to hearing through them from dedicated, desktop/Hi-Fi rigs like the LTA MZ3 or dCS Bártok, but the diminutive A&K DAP acquitted itself admirably nonetheless – coming across slightly leaner then I’d prefer through those rather ruthlessly revealing transducers. I mixed up my play time and critical listening of the A&norma between internally-stored DSD64, MP3 (mixes by Scott Eastlick) and high-res FLAC, and then tons of streaming via TIDAL and Qobuz which varied from 16-bit/44.1kHz to 24-bit/192kHz. Regardless of what I played through the SR15, it had an impressive midrange punch, timbral and tonal coloration of the pale rose variety (think good solid state), a slightly more sparkling treble than I’d prefer on some cuts (depending on the mastering), and most noticeable, a very black background which allowed a foundation of ease with which it presented the recorded event. It never felt like it was straining to be more than a straight-up high-fidelity product. It’s no tube amp, if you want that kind of warmth you’ll need to look elsewhere. No, the SR15 is content with its task of translating the binary data to the analogue realm without flourish or mid-bass bump.

The DSD 2.8MHz version stored on its internal 64gig memory of John Coltrane’s Blue Train had excellent sound stage presentation with instruments clearly defined from one another, and while not as brassy, full of blaat or as macho a presentation as through my McIntosh C2600 pre-amp’s headphone output, it was possessed of life, temporal accuracy and an innate liquidity which made long, fatigue-free listening sessions the norm. An 24-bit/96khz FLAC of Steely Dan’s Gaucho highlighted the SR15’s ability to render the full frequency spectrum evenly, without overt tilting to either treble or bass (when it was there, the treble usually faltered, not the lower notes), doing a decent job of keeping things neutral without getting into digital artifice or mechanical playback. “Into The Black,” off the Chromatics Kill For Love album on TIDAL (16-bit/44.1kHz), didn’t come across with as much bass depth, midrange definition or space around instruments and vocals as I’ve heard through the A&K SE100 for example, but the SE100 also costs $1,000 more, so keeping sonic expectations in-line with the cost/performance ratio of the $699 SR15, it certainly wipes the floor with my iPhone 7S via Lightning adaptor or Bluetooth.


If you’re looking for something pocket-friendly that can take advantage of digital audio in both a wireless and wired world and replace your mobile phone as your main music experience that does streaming services like TIDAL, Qobuz, Deezer or Spotify via wi-fi, has gobs of internal storage, can handle every file type imaginable, and won’t break the bank, then the Astell&Kern SR15 at $699 USD is a no-brainer. The increase in SQ over the iPhone/Lightning/Buetooth pairing is obvious, and the fact you don’t get interrupted by a call or text while listening is a huge bonus for me personally. When I’m listening to music, I’d rather not be distracted with social media, the Internet, etc. That said, the fact that the A&norma is a separate unit, it allows unhindered listening while you work on your laptop or scroll Instagram on your phone, so it’s a bit of a win-win from either angle. For the level of SQ, wired and wireless feature set, and future-fi that the SR15 has built-in at its price point, I can only highly recommend it.

  • General Specifications
  • Model: SR15
  • Body Color: Dark Gray
  • Body Material: Aluminum
  • Display: 3.3inch WVGA (480 x 800) TFT LCD
  • Frequency Response: ±0.030dB (Condition: 20Hz~20kHz) Unbalance / ±0.024dB (Condition: 20Hz~20kHz) Balance ±0.038dB (Condition: 10Hz~70kHz) Unbalance / ±0.065dB (Condition: 10Hz~70kHz) Balance
  • Signal to Noise Ratio: 122dB @ 1kHz, Unbalance & Balance
  • Crosstalk: 137dB @ 1kHz, Unbalance & Balance
  • THD+N: 0.0008% @ 1kHz, Unbalance / 0.0009% @ 1kHz, Balance
  • IMD SMPTE: 0.0004% 800Hz 10kHz(4:1) Unbalance & Balance
  • Clock Jitter: 70ps (Typ)
  • Supported OS: Windows 7,8,10 (32/64bit), MAC OS X 10.7 and up

Astell & Kern
19600 Fairchild Road, Suite 125, Irvine, CA 92612
(949) 336-4540/4541

jubei's picture

I have the exact same set up (SR 15 and iSine 20). So far, I'm impressed at the SR 15 as it offers more clarity than my previous (albeit less expensive) Fiio X5 3rd generation.

I'm curious about the Sony foamies you are using for the iSine 20; I'm using SpinFit tips at the moment and would sure like to explore to see what differences the tips make.

Rafe Arnott's picture
Was when I was using the Sony foamie headphones... they're a headphone, not tips.
jubei's picture

hahaha. Read the sentence wrong :P ...

Rafe Arnott's picture
Grant Ray's picture

The LCD-4z has similar specs to my Aeon Flow Closed from Mr. Speakers, but I feel the Aeons need drive more than their 93(sh) db/1mW suggest. I'm not sure 2Vrms will cut it. At least, not sure enough to plunk down without listening first. Alas.