Unlike the previous iterations that employed duralumin, the Astell&Kern AK240SS is constructed with stainless steel to take full advantage of its inherent benefits. Due to the extremely difficult processing techniques and high costs when compared to aluminum, stainless steel is generally reserved to high-end timepieces. We at Astell&Kern have created the most special version of the AK240 to date using stainless steel to bring you only the best.
Astell&Kern AK240 Stainless Steel // Digital Music Player with DSD 256GB
The unwavering strength of stainless steel.
At Astell&Kern, we study countless materials to remain faithful to our design philosophy: Deliver the unique beauty and pure essence of the raw material intact without needless processing.
“A strong, non-corrosive metal that does not easily bend or damage.”
“A metal that can restore damage through polishing.”
This type of metal is already widely used on high-end timepieces.
The clear sound of stainless steel.
One aspect of Hi-Fi and car audio absolutely cannot be overlooked. The ground eliminates noise that is inevitably generated by electrical signals in all products with electric circuits. Because the ground is one of the factors that can dramatically affect sound, it must not be neglected in Hi-Fi audio equipment such as the AK240. The standard AK240 utilized an anodized duralumin body with a few ground points applied via laser etching.
On the contrary, the AK240SS takes advantage of the entire pure stainless steel body as ground for a marked improvement in sound quality over the previous iteration through more ground points on a wider area.
Without any changes to the hardware or firmware, you will be able to experience a clearer, more focused sound previously unheard in the standard AK240.
Exceptional AK240SS Leather Case
In order to raise the bar of the AK240SS even higher, much attention was devoted to the selection of leather for the case.
The protective case made with leather from the world-renowned Tannerie Rémy Carriat complements the stainless steel body, adding even more value to the already-exceptional AK240SS.
Native DSD Support
What is DSD?
DSD (Direct Stream Digital) is a digital audio file format originally developed for SACDs (Super Audio CD). Regular digital audio file formats such as PCM (Pulse Code Modulation) is separated into 65,000(16bit) to 16,700,000(24bit) of information on the Y axis, and 44,100(44.1kHz) to 192,000(192kHz) across the X axis for digital signals. DSD files have 1bit (0s or 1s) for Y axis and is separated into 2,800,000(2.8MHz) to 5,600,000(5.6MHz) of information for X axis.
Compared to regular audio CDs with 16bit/44.1kHz PCM format, SACD’s recording frequency goes up to 100kHz and the dynamic range goes beyond 120dB while maintaining sound clarity during the transmission.
One of the approaches A&K decided that would help them move a step closer to the original sound quality was to provide native DSD playback without having to convert it into PCM. This was indeed a difficult task. In order to provide native DSD playback on the AK240, we had to select a different DAC chipset. Making the decision to change the DAC was not easy, but in order to reach their goal, they had to make a bold move which was to start from scratch.
A&K asked themselves: Does the DAC support Native DSD?
Will it allow for the Dual DAC setup? What else is needed for the perfect Native DSD support?
In order to answer these three questions, they have decided to use the Cirrus Logic CS4398 chip in the Dual DAC setup with an added exclusive XMOS chip that will allow for Native DSD support.
The process of setting up Native DSD support was not an easy task. Since the main CPU does not process Native DSD, they needed a chip that will work with it. It took A&K a long time, they we made it work. Through countless hours of testing, A&K was able to achieve Native DSD playback by having the main CPU process the data, send it to the exclusive XMOS chip, then through the DAC to deliver the sound.
Unbalanced vs. Balanced Output
The unbalanced method is the most commonly used basic method which consists of “left and right signals + ground line”. This setup includes a ground line which blocks out external noises from the outside. However, since the ground line cannot block out all of the external noises completely, external noises can be mixed into the signals that are transmitted, which then result in changes to the sound. The longer the signals travel, the more external noises that will be mixed into the sound which is why it is used within a short distance of 1 to 2 meters.
Unlike the unbalanced method, the balanced method has an additional cold signal to compliment the hot signal which reduces the external noises.
Dual DAC meets Balanced Output
It did not take A&K long to figure out that the AK240’s Dual DAC and balanced output resulted in the best sound. During the development of the AK100 and AK120, Astell&Kern’s specific analogue amp setup was already creating full balanced analogue signals streaming from the DAC and they were able to move a step closer towards the original sound by then creating a balanced output terminal at the end.
256GB of Massive Storage
Astell&Kern has created the AK120 Titan with a storage capacity of 128GB, but in order to support Native DSD, MQS, and massive audio files, they had to come up with the ultimate portable music player with 256GB of storage. With 256GB of internal memory, about 2,500 MQS (24bit/96kHz, 4 minute-long, 90MB) songs can be saved. With the addition of a 128GB microSD card, the AK240 can support up to a total memory capacity of 384GB.
|Display||3.31inch WVGA (480 x 800) AMOLED Touchscreen|
|Supported Audio Formats||WAV, FLAC, WMA, MP3, OGG, APE(Normal, High, Fast), AAC, ALAC, AIFF, DFF, DSF|
|Sample rate||FLAC, WAV, ALAC, AIFF : 8kHz ~ 192kHz (8/16/24bits per Sample)/ DSD : DSD64 (1bit 2.8MHz), Stereo / DSD128 (1bit 5.6MHz), Stereo|
|Output Level||Unbalance 2.1Vrms / Balance 2.3Vrms (Condition No Load)|
|DAC||Cirrus Logic CS4398 x2 (Dual DAC)|
|Decoding||Supports up to 24-bit / 192kHz Bit to Bit Decoding|
|Inputs||USB Micro-B input (for charging & data transfer (PC & MAC)) Connection Mode : MTP (Media Device)|
|Outputs||PHONES (3.5mm) / Optical Out (3.5mm) / Balanced Out (2.5mm, only 4-pole supported)|
|Dimensions||2.16 ”(55 mm) [W] x 4.64 ”(118 mm) [H] x 0.58 ”(14.9 mm) [D]|
|Weight||6.24 oz (177 g)|
|Wi-Fi||802.11 b/g/n (2.4GHz)|
|Feature Enhancements||Firmware upgrades supported (OTA)|
|Frequency Response||±0.023dB (Condition: 20Hz~20kHz) Unbalance & Balance / ±0.3dB (Condition: 10Hz~70kHz) Unbalance & Balance|
|Signal to Noise Ratio||116dB @ 1kHz, Unbalance / 117dB @ 1kHz, Balance|
|Crosstalk||130dB @ 1kHz, Unbalance / 135dB @ 1kHz, Balance|
|THD+N||0.0007% @ 1kHz, Unbalance / 0.0005% @ 1kHz, Balance|
|IMD SMPTE||0.0004% 800Hz 10kHz(4:1) Unbalance / 0.0003% 800Hz 10kHz(4:1) Balance|
|Output Impedance||Balanced out 2.5mm (1ohm) / PHONES 3.5mm (2ohm)|
|Clock Jitter||50ps (Typ)|
|Capacity||3,250mAh 3.7V Li-Polymer Battery|
|Built-in Memory||128GB [NAND]|
|External Memory||microSD (Max 128GB) x1|
|Supported OS||Windows XP, Windows Vista,7,8 (32/64bit), MAC OS X 10.7 and up|