Tel: 02 9427 6755

Astell and Kern - AK240


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It’s one thing to have Hi-Res high fidelity happening on your main system and quite another to have it in a neat, portable unit like the Astell & Kern. Following on from their earlier models, the AK100 and 120, the AK240 aspires to the ultimate reproduction via (among other things) native DSD capability. Although designed as a portable unit, it is of such high quality that it can be your source of HD tracks in any system. (See also the 2nd Generation AK120 II )
The company explains it as follows:
One of the approaches we decided that would help us 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 our goal, we had to make a bold move which was to start from scratch.

We have asked ourselves: 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, we 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, we needed a chip that will work with it. It took us a long time, but we made it work. Through countless hours of testing, we were 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.
Part of the ultimate solution was to use 2 x Cirrus CS4398 DACs and balanced outputs! The internal memory of 256GB can be supplemented by a 128GB SD card, for a total of 384GB. This gives the unit plenty of storage for Hi-res music, which consumes more memory than your usual CD albums by a factor of about four to ten, depending on the data type: the higher the res, the more space it takes up. Hi-Res is not a single standard, and albums are not a standard length. The 384GB should, as a rough guide, translate into being able to take around 100 Hi-Res albums or the equivalent in tracks along with you, to enjoy when away from your home system and your local network’s bulk storage.
General Specifications
Model: AK240
Body Color: Gun Metal
Body Material: Aircraft Grade Duralumin
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 Native : 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 Support: up to 24bit/192kHz Bit to Bit Decoding, DSD64/128
Input: 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)
Wi-Fi802.11 b/g/n (2.4GHz)
Bluetooth V4.0
Dimensions: 66x107x17.5mm (whd)
Weight: 185 g
Feature Enhancements: Firmware upgrades supported (OTA)

Audio Performance
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)



Contact Len Wallis Audio

Address: 64 Burns Bay Road,
Lane Cove NSW 2066,
Telephone: (02) 9427 6755