Astell & Kern AK HC4 DAC and Amp

Astell & Kern

Astell & Kern AK HC4 DAC and Amp

Astell & Kern AK HC4 DAC and Amp
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HiFi Sound on the Move, AK HC4

Astell & Kern offers a HiFi USB DAC cable product range for a true HiFi experience on smartphones and PCs. 
The HiFi sound provided by Astell & Kern's design, which was completed in a small size, has won praise from countless audiophiles and media.

Astell & Kern AK HC4 DAC and Amp laying on a black surface

The AK HC4 continues the advantages of its highly acclaimed predecessors, delivering even more perfected sound in various usage scenarios through advanced design. Featuring Dual Output, compatible with most IEMs and headphones, the AK4493S DAC for true HiFi sound, and Digital Audio Remaster technology, it brings the level of HiFi sound previously exclusive to Astell & Kern's digital audio players to the AK HC4. Enjoy HiFi sound like never before.

  • 3.5mm, 4.4mm Dual Output
  • AKM AK4493S
  • DAR (Digital Audio Remaster)
  • Supports iOS devices
  • Interchangeable Cable (Type-C / Lightning Cable Included)
  • Supported UAC1.0 (For Gaming System)
  • Roon Tested

The Astell & Kern AK HC4 DAC and Amp connected to a mobile phone

Sound in ultra-high resolution sound from AKM AK4493s DAC

To achieve the highest audio quality achievable with a USB DAC, the AK HC4 is the first in the USB DAC Cable lineup to incorporate AKM's DAC. AKM's DAC has earned much love when featured in Astell & Kern's digital audio players, but due to the small size of USB DAC Cables and the challenges of amp design, it has been difficult to implement in the USB DAC Cable lineup until now.

The AK4493s DAC from AKM, used in the AK HC4, is further enhanced with improved noise control, lower power design, and ultra-precise amp design technology, delivering exceptionally high-quality HiFi sound. Furthermore, it supports Native DSD256 and up to 32bit/384kHz to handle any high-quality audio source, allowing you to experience the high-grade sound quality that Astell & Kern delivers.

A Astell & Kern AK HC4 DAC and Amp plugged into a mobile phone and a pair of earphones

Precision DAC and AMP Design for HiFi Sound

In order to gain stable output power and ultra-high-quality HiFi sound through the Dual Output, AK HC4 introduces an exclusive AMP circuitry that supersedes the standard built-in DAC AMP.

While maintaining a compact form factor 29.5 x 64.5x 14.5mm, A&K used micro resistors and capacitor parts to achieve a small footprint without compromising performance. Carefully selected ultra-small tantalum capacitors, which are used in AK player products to create a stable system and audio performance by controlling the power fluctuations, are also included to create an optimal audio circuit design. In addition, the output and audio performance are enhanced with Astell & Kern's unique power management technology to minimise current consumption in respect of the connected device.

3.5mm, 4.4mm Dual Output

The AK HC4 features Dual Output with both 3.5mm and 4.4mm connectors, allowing you to use AK HC4 with most HiFi IEMs and headphones without the need for adapters or additional cables.

The 4.4mm Balanced output provides a high output of 3Vrms, maximising the performance of sensitive headphones and IEMs, while ensuring clear channel separation and minimal noise.

The 3.5mm Unbalanced output is compatible with the majority of existing IEMs and headphones, offering a sufficient output of 2Vrms to fully experience the capabilities of your IEMs.

The Astell & Kern AK HC4 DAC and Amp connected to a laptop

Digital Audio Remaster Technology for Even More Vivid Original Sound

The AK HC4 is equipped with digital audio remaster (DAR) technology, which was only applicable to the latest digital audio players from Astell & Kern.

DAR technology is developed to upsample the sample rate of the sound source being played to go beyond the limits of the source format. The high sample rate allows more refined play and offers delicate and analogue-like original sound, helping you to enjoy the richness of the original sound, subtle differences in the nuance of the music and rich sounds at a higher level.

In addition, the DAR slide key on the side of the product gives you a more intuitive selection of DAR options.

High Compatibility and Simultaneous Support for UAC 1.0 & 2.0 for Gaming

While modern smartphones, tablets, and PCs support UAC 2.0 connections, many gaming devices still exclusively support UAC 1.0 connections.  To cater to both scenarios, AK HC4 ensures compatibility by supporting both UAC 2.0 and UAC 1.0 connections for cross-platform quality sound experiences.

Connect AK HC4 to your gaming device such as PlayStation and Switch, and enjoy low latency and enhanced sound for an immersive gaming experience.

Astell & Kern AK HC4 on a table plugged into a Nintendo Switch with earphones close by

Noise-Free Rear Output Structure

AK HC4 incorporates a rear audio output design to minimise noise.  Most USB DAC products have the DAC positioned in the USB terminal that is connected directly to the device to process and output audio.

However, with the HC4, digital signals from the device go through the dual shielded cable to the audio circuit before being converted to an analog signal by the DAC.  By processing the digital signal after, the result is superior, noise-free sound compared to other USB DAC products.

Dual Noise Shielded Cable

To ensure optimal usability across both Android and iOS devices without the need for additional adapters, AK HC4 features an interchangeable cable that readily supports Type-C and Lightning connections.

The AK HC4 features a dual shielded cable to minimise noise and deliver a more vivid, original sound.  The copper core wire is coated with tin to prevent corrosion and strengthen tensile force for enhanced durability.

A cross section of the cable

Additionally, the entire cable is wrapped in an aluminium film to block noise with an extra layer of shielding around the power cable to further minimise noise, the biggest issue in audio, then the tin-coated copper wire is woven to minimise noise interference to sound.

Finished with a fabric jacket on top of the TPE jacket, the cable features enhanced durability and usability with perfect aesthetic appeal.

LED for real-time indication

AK HC4 has an LED indicator located on the front, that displays song details and USB Connection.

Precautions When Using the Product

This product is compatible with most Android and iOS smartphones and tablets, Windows 10/11 and macOS products. In some cases, it may not be compatible or may be restricted depending on the hardware, software and/or system of the device that you connect to.

When connecting to a Windows PC, the driver will automatically be recognised and installed. For high-quality sound files, you are required to install a separate USB DAC driver which can be downloaded from the Support — Download section on the website.

4-pole earphones and headphones support CTIA devices, but OMTP is not supported.

To play DSD and high-quality PCM sound files on a smartphone, you must install a separate free/paid player program that supports high-resolution audio playback. (When using the default player app on a mobile device, the file will be downsampled. Please make sure to play it with a different player app.)

Please note that the volume will be fixed to the maximum level if you allow access with Tidal and some other apps on Android devices.

Make sure to check the volume on your connected player device before using headphones or earphones. Some devices may automatically set the output level to maximum volume when the cable is connected. Listening to headphones or earphones at maximum volume may damage your hearing. Please verify the volume level before each use.

Do not connect the USB-C DAC Cable to an Astell & Kern player. When connecting the cable to a player and using it as an external DAC, the output volume will be fixed at the maximum volume setting. It is not possible to adjust the volume through the Astell & Kern player. Listening at maximum or a high-volume setting may cause serious damage to your hearing. Astell & Kern, its affiliates and agencies, cannot be held liable for any damage or injuries from negligent or inappropriate use.

Firmware updates may be released periodically for stability improvements. For more information on firmware updates and to check if a firmware update is available, please visit the Support — Download section on the website.

roon Tested

Roon plays to thousands of USB, Airplay, and Chromecast devices, but Roon Tested devices are profiled by the Roon team to ensure simple setup and effortless daily use.

If you own a Roon Tested device or are thinking about buying one, you can have the confidence that you will enjoy the best possible experience of it.


The AK HC4 is small in size, but it inherits Astell & Kern's design philosophy, Light and Shadow, through simple yet delicate design elements.

By adopting a unibody structure, the bonding line is minimised to complete the smooth and clean appearance, and the overall appearance of the product is even more complete.

It has a design that can minimise the burden of size caused by simultaneous 3.5mm and 4.4mm Dual Output. 
In particular, the front edge line is designed to be symmetrical left and right so that the line is gathered in the centre, creating a balanced look that naturally focuses the gaze in the centre.

The side of the product is designed with concave lines, making it easy and comfortable to use in a form naturally tailored to human hands.

In addition, the keys on the sides are either lifted at both ends or divided into dot embossed details, allowing the user to use each function separately only with the sensation of the fingertips.

  • Model: AK HC4
  • Body Colour: Moon Silver
  • Body Material: Aluminium
  • DAC: AKM AK4493S
  • Sample rate: 
    • PCM : 8kHz ~ 384kHz (8/16/24/32bits per Sample)
    • DSD Native : DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo / DSD256(1bit 11.2MHz), Stereo
  • Output Level: Unbalanced 2Vrms / Balanced 3Vrms (Condition No Load)
  • Input: USB Type-C (Supports UAC 1.0 and UAC 2.0)
  • Output: 3.5mm (Unbalanced), 4.4mm (Balanced, Only 5-pole supported)
  • Dimensions: 29.5mm[W] x 64.5mm[H] x 14.5mm[D]
  • Weight: About 1.09oz (31g)

Audio Specifications

  • Frequency Response: 
    • ±0.062dB (Condition : 20Hz~20kHz) Unbalanced │ ±0.063dB (Condition : 20Hz~20kHz) Balanced
    • ±0.066dB (Condition : 20Hz~70kHz) Unbalanced │ ±0.067dB (Condition : 20Hz~70kHz) Balanced
  • Signal to Noise Ratio: 118dB @ 1kHz, Unbalanced │ 118dB @ 1kHz, Balanced
  • Crosstalk: -134dB @ 1kHz, Unbalanced │ -136dB @ 1kHz, Balanced
  • THD+N: 0.0005% @ 1kHz, Unbalanced │ 0.0009% @ 1kHz, Balanced
  • IMD SMPTE: 0.0005% 800Hz 10kHz (4:1) Unbalanced │ 0.0004% 800Hz 10kHz (4:1) Balanced
  • Output Impedance: Unbalanced Out 3.5mm (0.9ohm) │ Balanced Out 4.4mm(1.6ohm)

Overall Rating