Analog waves.

PROS: R-2R discrete DAC, Class A and Class AB amp modes, NOS/OS modes, hi-res 5.46” display, updated fast user interface, 2.5mm/3.5mm/4.4mm PO/LO, MQA, DSD256, LDAC Bluetooth (both Tx and Rx), 256GB internal storage, hi-res analog sound with smooth detailed tuning.

CONS: price, case not included.

The product was loaned to me for the review purpose in exchange for my honest opinion.

Manufacturer website: Astell & Kern.  Available for sale directly or from on-line retailers like Bloom Audio and Musicteck.

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Intro.

When it comes to Astell & Kern, their A&ultima (SP series) flagship releases are often considered to be early adopters of the latest AKM DACs, such as SP1000 and AK4497, SP2000 and AK4499, and SP3000 with AK4499EX/4191EQ.  Then, their more budget-oriented A&norma (SR series) are optimized for portability and exceptional battery life while on the go.  But it’s their A&futura (SE series) where you are going to find all the cool new features, like a dual independent DACs design in SE200 or a modular design in SE180.  Thus, it came as no surprise when A&K announced their first discrete all resistor DAC design to be featured in SE300.

In addition to an all-discrete R-2R DAC, Class A and Class AB selectable amp modes, and NOS and OS oversampling modes, SE300 also features the same new digital platform as in their flagship SP3000 which includes faster processor and newly updated and more responsive interface.  This all-new A&K DAP is going to make its debut at the upcoming High End Audio show in Munich.  Luckily, I got a chance to spend a week with it, and now would like to share what I found.  Originally, it was supposed to be just a First Look short review, but as I started testing, I ended up with a full write up of A&K SE300.

Unboxing and Accessories.

Since I received SE300 without the official packaging, I’m not able to share unboxing pictures, but was told the experience should be like their previous A&futura SE-series DAP releases.  Thus, we should probably expect a more compact storage box along with additional accessories like screen protectors and quality USB-C high speed cable for charging, data transfer, and USB DAC functionality.  I’m sure, a quick start guide, and a warranty card will be included as well.

One thing to note, SE series usually comes without a leather case.  These DAPs are beautiful to look at and I hate putting them in a case, but I find it necessary to enhance the grip for a more secure handling, especially on the go.

Design.

With its dimensions of 139.5mm x 76.5mm x 17.6mm, SE300 is very close in size to its big brother, flagship SP3k, though it is lighter at about 317g vs 494g (SP3k).  I wasn’t surprised here since they used the same size display and needed extra room for discrete resistors.  The weight is probably lighter due to chassis material, which is a mix of aluminum and stainless steel, unlike SP3k which uses Stainless Steel 904L.  At the time of the release, the only available color is platinum silver.

The focus of the design is still around a large 5.46″ HD touch screen occupying the front view.  This time, the front view of the DAP is more symmetric since only the right side has a slightly bulging-out area with a sculptured wavy design, just a bit recessed around the volume wheel.  And just like in SE180, there is a separate power button at the top in the right corner, with a typical long press to turn the power on/off followed by confirmation to shut down or a short press to turn the screen on/off, though personally I like a double tap to wake up the screen.  After using SP3k, I often forget and try to push the volume wheel, forgetting that SE300 has a separate power button.

The volume wheel is easy to turn using a thumb, though it’s not loose and has some resistance with a click action felt with every rotation turn of 150 volume steps.  Implemented here is also a multi-function LED behind the wheel to indicate charging status or bit depth depending on the source file (16bit – red, 24bit – green, 32bit – blue, DSD – purple).  LED light could be disabled in Settings, and you can also enable/disable LED indicator light intensity as you adjust the volume.  The design of the volume wheel has a unique crown pattern with a copper center, a design reminiscent of a wristwatch.

On the left side you have Play/Pause and Skip controls, three identical small rectangular buttons located in the upper part of the left side in the slightly recessed area.  They do have a nice tactile response and spaced evenly with just enough room in between to avoid pressing an adjacent button by mistake, unless you have “fat” fingers.  The top of the DAP has access to 3.5mm phone output port which also used for Line Out and Optical out.  Next to it, you have 4.4mm and 2.5mm balanced phone ports that could also be configured for corresponding Line Out.  All the way to the right you will find a power button.

At the bottom to the left, you will find a spring-loaded microSD card slot.  In the middle, there is USB-C port, used for charging (including Fast Charging), data transfer, USB DAC connection, and USB OTG external device connection for digital audio out.  The back of the DAP has a symmetric design with a carbon fiber back panel.  Overall, the shape of SE300 is rectangular and the exterior design has less aggressive lines, not as flashy as their other DAPs.

Under the hood.

Unlike the traditional Delta-Sigma DACs from AKM, ESS, TI/PCM, or CS, SE300 uses R-2R Ladder DAC which is made of discrete matching resistors.  There are different implementations of this design, and A&K settled on a fully discrete 24bit R-2R precision DAC which requires 48 pieces of resistors per channel, a total of 96 ultra-precision resistors.  And these are not some generic off the shelf components, but rather matching parts with a high accuracy tolerance of +/-0.01%.

In addition to R-2R discrete DAC, A&K also implemented new dual amp architecture with a selectable Class A and Class AB amp modes.  Plus, they utilized a selectable Over-Sampling (OS) and Non-Over Sampling (NOS) modes which have different sound processing implementation and reproduction.  Furthermore, I was pleased to see 2 gain settings, Normal (NG) and High (HG), which could be useful when dealing with some sensitive IEMs.  I will go over how I hear sound differences of these different options in the Sound Analysis section of the review.

Keeping up with their 2.5mm balanced “legacy”, just like SP3k flagship, SE300 includes all 3 headphones outputs, 2.5mm, 3.5mm, and 4.4mm.  The single ended 3.5mm PO has output impedance of 1.3ohm and 2Vrms (NG) and 3Vrms (HG) and balanced 2.5mm and 4.4mm POs have output impedance of 1.3ohm and 4Vrms (NG) and 6Vrms (HG), with Vrms measurements based on unloaded condition.  Each port can be switched to Line Out, and 3.5mm also has Optical SPDIF output.

SP3000 vs SE300

The touch display is 5.46” HD with1920×1080 resolution, the same as in SP3k.  The interface is very fast, like just in SP3k, noticeably faster than in other A&K DAPs.  I didn’t see in the spec if this is the same Snapdragon 665 SoC as in SP3k, but I suspect it could be due to the same interface speed.  This is still closed Android so it is hard to compare to other open Android DAPs since I can’t run 3D benchmark test app.  There is plenty of processing power to do flawless audio decoding while supporting all the popular lossy and lossless formats, such as WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, and DSF, with PCM rates up to 32bit/384kHz and DSD rates up to DSD256.  Also, MQA playback support, covering Tidal Masters, Local files, External USB, and MQA-CD (ripped).

The internal storage is 256GB just like SP3k, and you also get microSD external memory expansion up to the latest largest capacity card (A&K tested with 1TB).  I guess it doesn’t matter as much today since many people are streaming and high-capacity microSD cards are relatively cheap.  Furthermore, USB-C OTG supports external hard drive storage or usb stick expansion.  It even uses the same high capacity 5,050mAh (3.8V LiPo battery) and supports fast charging (QC3.0) to give you a full charge in about 3.5hrs (under 9V, 1.67A charging condition).  I did run a battery test, and from 4.4mm bal output in High Gain with Class AB and NOS selected while playing hi-res flac files in the loop, I was getting about 11.5hrs of playback time with occasional screen usage to check battery status.

To support fast charging and to speed up data transfer, SE300 uses USB 3.0 Type-C interface for charging, data transfer, and USB DAC functionality.  WiFi is dual band, supporting both 2.4GHz and 5GHz.  Along with that you have OTA firmware update support and of course streaming of many popular apps.  Furthermore, Bluetooth is up to 5.0 with a wireless support of not only aptX HD but also LDAC protocols for 24-bit playback over Bluetooth, plus both Bluetooth Rx and Tx.

Page 2 – GUI overview, Open APP Service.
Page 3 – Sound Analysis, Comparison.
Page 4 – Pair up, Wired/wireless connections, and Conclusion.