Pair up.

Here is how SE300 pairs up with some IEMs and headphones.  In each pair up I noted my preference of gain setting and amp mode setting.  All were connected using 4.4mm BAL.

IEMs.

FirAudio RN6 – High gain boosted the bass impact, pushing it more toward L-shaped sound sig.  Then, Class A made lower mids thicker in tonality, taking away clarity from the mids.  Thus, I preferred to switch to Normal gain and Class AB which made the sound sig more balanced, improving bass control (decay), and giving mids more clarity and better retrieval of details.

Aroma Jewel – Here, I preferred high gain over normal because it gave its DD bass more texture, tighter control, and better articulation.  With amp modes, I thought that Class A sounded better due to more revealing nature of Jewel’s tuning, but Class A took a step back in terms of resolution and made mids a bit smoother for my liking, so I switched back to Class AB for higher resolution and more precise layering.

EE Odin – This one was a bit of a surprise because I thought Odin’s DD bass will be a perfect fit with High gain, but it made upper frequencies a bit piercing to my ears, so I switched to Normal gain which made upper mids and lower treble sound more natural in tonality.  With Class A vs AB, it wasn’t even a question, A added more warmth to the mids, giving the sound more organic tonality without compromising the resolution, so Normal gain with Class A hit the sweet spot with Odin to my ears.

UM Mentor Multiverse – here, either Normal or High gain made no difference in tonality, aside from me just adjusting the volume.  So, either one is fine with MM.  But Class A vs AB did make a noticeable difference, giving the sound a more laidback tonality with A vs “sharpening” the details and improving layering and separation of the sounds with AB.  Also, with Class AB I can hear a bit more air in treble.  For MM, I enjoyed Normal gain and Class AB.

Headphones.

Audio-Technica ATH-R70x – As I already mentioned, R70x came alive when switching to High gain.  I heard improvements in sound dynamics, with more vertical expansion vs being a bit more compressed in Normal gain.  Also, bass sounds tighter, faster, more precise in High gain.  With amp mode selection, Class AB complemented nicely the High gain setting, improving the layering and separation of the sound.  In comparison, Class A made mids a bit duller, losing some of the nuances in sound and having lower level of detail retrieval.

Meze Audio Empyrean – When it comes to full size and planar magnetic, you would assume that high gain will be better, but turned out that here it made no difference with either High or Normal gain, just had to adjust the volume to compensate for lower gain.  But it made a noticeable difference switching Class A vs Class AB.  Class A made mids a bit muffled and took away from clarity in vocals.  Switching to Class AB improved the retrieval of details and “cleaned up” lower mids to give vocals better clarity.

Wired and wireless connections.

Besides being a portable DAP, you can expand SE300 functionality as a transport to drive external DAC/amp, to use external AMP, or to turn the DAP into wired/wireless usb DAC.  And of course, you don’t have to be limited to wired headphones, and can take advantage of Wireless Bluetooth connection.  Here is what I tested.

WiFi Streaming.

As I already mentioned, while SE300 has a closed Android system, you have a whitelist of available popular streaming apps to install.  These are full app versions that look and function the same as if you would be running it on your Android smartphone or Android DAPs.  Also, you no longer need to rely on a floating “back” button since this one is fixed at the bottom.  Furthermore, while running streaming apps, you can swipe down the notification bar to see app’s playback controls.

Wireless/Bluetooth.

I tested SE300 BT Tx with Final ZE8000 TWS and Hiby WH2, confirmed operation within 25ft, including full remote control.  25ft operation in open space was OK and the sound was the same as when connected to my S22, except I get close to 50ft when using it with my smartphone.

SE300 also has Bluetooth Sink Mode (BT Receiver) which sets the DAP as a wireless DAC/amp.  Under Bluetooth setting of SE300, turn on Sink Mode and then scan for BT devices from your phone to pair up with SE300.  Once connected, under the paired-up device on your smartphone click settings and turn on LDAC for SE300.  The volume can be adjusted from both your smartphone and DAP, and SE300 will display the song/artists name, and I was able to control the playback (play, pause, skip) straight from the DAP.

USB Audio Out.

I tested and verified this one with various popular USB DAC dongles, such as Cayin RU6, Lotoo S2, and L&P W2, and found it to work flawless, just plug and go.  Once connected, volume on SE300 is fixed at max 150, thus it is helpful to use external USB DAC dongles with their own volume control.  The sound quality was no different than when connected to my Galaxy S22 phone.

USB DAC.

Tested this one with my ThinkPad T480s under Win10.  Once connected, by default USB mode is set to MTP so you can view the storage.  In settings of the DAP, go to USB Mode and select DAC Input which going to activate USB DAC mode.  Within seconds SE300 was recognized as AK USB DAC output in Windows sound settings, and I was able to control the volume from both, the laptop and SE300.  The sound using DAP by itself vs USB DAC connected to the laptop was the same.

Optical Out.

Was using iFi micro iDSD BL for this testing, nothing needs to be selected or enabled, just connect optical cable to 3.5mm port and start playing.  Optical output was detected automatically, SE300 volume was set to max 150, and I was controlling the output from micro iDSD.  Other than that, no surprises using SE300 as a transport to drive the external DAC/amp where I’m hearing a typical micro iDSD tonality.

Line Out.

I tested LO with Cayin C9 amp.  Just connect either SE or BAL outputs, select Line Out from Notification bar shortcut or go to Settings, and under Line Out option select the output voltage level where you have 4 choices of unbal/bal: 0.7V/1.4V, 1V/2V, 1.25V/2.5V, or 2V/4V.  Then, as you turn the volume wheel, you activate Line Out by switching it to a fixed voltage output.  The volume was adjustable from C9 amp.

Conclusion.

As I already mentioned in my other DAP reviews, we are at the point where it is hard to come up with groundbreaking innovations, and there is no longer a huge gap between mid-fi, upper mid-fi, and summit-fi audio performance.  When it comes to Astell & Kern and their flagship A&ultima (SP) releases, their focus is more on fine tuning improvements rather than drastic changes in sound or the design.  On the other hand, their A&futura (SE) series became a platform for cool new features you won’t find in A&ultima.  This was the first one for A&K, stepping away from a traditional design with Delta Sigma DACs, and switching to an all-discrete resistor ladder design of R-2R DAC, complemented with Class A and Class AB amp modes, and even NOS to bypass the oversampling.

It’s not the first DAP to implement these features or R-2R discrete resistor DAC design, but it’s one of the first A&K DAPs with such a plethora of sound tuning options that was truly a fun to play around with as I was switching between Gain settings, Amp modes, Oversampling and Non-Oversampling to find a sweet spot while fine-tuning the natural analog tonality of this hi-res DAP in search of the best pair-up synergy with my earphones and headphones.  SE300 will appeal not just to diehard fans of A&K DAPs, but also to many other audiophiles looking to complement their one-trick pony sources with something different and more fun.  I think even SP3000 owners will find SE300 quite appealing.