Astell&Kern AK100 II Digital Audio Player

A New Standard
A new standard for listening to music was proposed while developing the AK100.
We recognized that certain aspects of the AK100 needed improvement during research and development for a successor.
While considering how to improve the AK100, we realized that there was a difference between measured audio specifications and what we felt sounded good. After much deliberation, our development efforts were focused on making the AK100 2nd Generation "feel" right to our senses rather than mechanically boosting technical specs. The original AK100 was developed according to audio specification standards, but development of the next-generation AK100 was developed to the "New Standard" of how the music sounds. We present "A New Standard in Listening to Music" with the AK100 2nd Generation.

Single DAC and Balanced Out
Although the dramatic depth in sound quality delivered by the Balanced Out was proven in our flagship model, we wondered if the same benefit could be gained by implementing the Balanced Out with a Single DAC. The newly designed demo board delivered the ear-pleasing sound quality we needed. The value of a Balanced Out with a Single DAC is confirmed with every musical note. The AK100 2nd Generation provides a rich, warm sound experience through the re-tuned A-amp designed specifically for the CS4398 Single DAC.

Single DAC's Balanced Output

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. The balanced method has a few advantages over the unbalanced method. The first advantage is that the hot signal and the cold signal will remove the external noises received. The second advantage is increased output due to the 2 transmitted signals. Since the ground line cannot block out 100% of the external noises, noise will appear on both the hot and cold signals. The alignment of the 2 signals allows the noise to usually appear at similar points where they will eventually be removed as the signals are transmitted.

5.6 MHz DSD Support
We realized DSD playback through a firmware upgrade for the AK100. However, only 2.8 MHz DSD was supported (88.1kHz PCM conversion/downsampling) due to hardware limitations. Now, 5.6 MHz DSD is supported via 'DSD to PCM' by utilizing a Dual Core CPU.

USB DAC
The AK100 2nd Generation fully supports USB DAC. The AK100 2nd Generation also functions as an external DAC (sound card) when connected to a PC or Mac via USB. The AK100 2nd Generation's sound quality is available for stored music on any PC or Mac as it serves as a built-in sound card.

Network Playback - MQS Streaming
With the next-generation AK100, it's no longer necessary to turn on the PC, search for music, connect a device, and transfer files.
Simply connect the AK100 2nd Generation to your PC or Mac via Wi-Fi on the same network and download or stream music wirelessly.

OTA (Over-The-Air) Upgrade
It has been 14 years since iriver has used the term: firmware. It already has been 14 years since when our customers had to check their email or look for notifications on the iriver website to look for new firmware. Now, as long as you are connected to Wi-Fi, we notify you of firmware updates as soon as they launch and from wherever you are.

Full Touch Screen
The new AK100 2nd Generation utilizes a 3.31" AMOLED screen, an 82% increase over the previous screen's size. Now, users have access to more on-screen information than ever before. In addition, a full touchscreen means convenient, smartphone-style control. The Album View screen has been completely overhauled. The larger screen offers a view of six albums compared to the previous version's four, and the album art view offers intuitive search functionality.

A More Detailed 10-Band 0.5 dB Step EQ
A more accurate EQ setting is available by doubling the bands (from 5 to 10) and halving the dB steps (from 1 dB to 0.5 dB). In addition, multiple user EQs are supported so that users may create custom EQs to fit each music genre and change them whenever desired.

64GB + microSD 128GB
The AK100 2nd Generation includes 64GB of internal flash storage. With the addition of a 128GB microSD card, the AK100 2nd Generation supports up to a total memory of 192GB. With 64GB of internal memory, the AK120 2nd Generation can store about 625 MQS (24bit/96kHz, 4 minute-long, 90MB) songs.