The Dongle DAC market has been a runaway train for almost 3 years and whilst there is no shortage of great options from almost 20 high-end brands, sales have definitely slowed down and manufacturers are starting to strip away features that they deem unnecessary and which only add more costs to the manufacture of said products. The new Astell&Kern HC4 is a prime example of that.
The HC4, which follows the release of the HC3 Dongle DAC in 2022, is expected to sell for $220 when it goes on sale in December.
What’s New?
Deciding between the HC3 and HC4 depends on a few key factors.
- The HC4 uses an AKM DAC chips versus the ESS DAC in the HC3.
- HC4 includes both 4.4mm and 3.5mm headphone jacks, Digital Audio Remaster (DAR) to upsample PCM and DSD, and supports both UAC 2.0 and UAC 1.0 for use with gaming systems.
- HC3 includes only 3.5mm headphone jack but does include support for gaming headsets with mics and MQA decoding. HC4 does not include support for MQA or mics.
- Cables are removable/replaceable on HC4 and includes USB-C to USB-C and USB-C to Lightning cables. HC3 has USB-C cable attached and a USB-C to Lightning adapter for iOS devices.
Astell&Kern HC4
The new AK HC4 is Astell&Kern’s fourth USB DAC/Headphone amplifier designed to provide playback of high-resolution audio from your computer or mobile device. With more mobile phone manufacturers removing headphone jacks from their devices, the Astell&Kern AK HC4 USB DAC provides users the ability to get the best sound possible out of their mobile devices while using headphones and earbuds they already own.
The AK HC4 features an AKM AK4493S DAC chip which supports native playback of high-resolution audio up to DSD256 and 32bit/384kHz PCM. It is the first Astell&Kern USB DAC to incorporate an AKM DAC.
AKM DACs have earned much love when featured in Astell&Kern’s digital audio players, but due to the small size of USB DACs and the challenges of amp design, it has been difficult to implement this DAC 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 Hi-Fi sound.
Dual Outputs
The AK HC4 features Dual Outputs with both 3.5mm and 4.4mm connectors, allowing you to use the AK HC4 with most Hi-Fi IEMs and headphones without the need for adapters or additional cables.
The 4.4mm balanced jack provides a high output of 3Vrms, maximizing the performance of sensitive headphones and IEMs, while ensuring clear channel separation and minimal noise.
The 3.5mm unbalanced jack is compatible with the majority of existing IEMs and headphones, offering a sufficient output of 2Vrms to fully experience the capabilities of your headphones and IEMs.
To gain stable output power and ultra-high-quality Hi-Fi sound through the Dual Outputs, the AK HC4 introduces an exclusive AMP circuitry that supersedes the standard built-in AMPs used in most USB DAC designs.
To maintain a compact form factor of 29.5 x 64.5x 14.5mm, Astell&Kern 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 in the AK HC4 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 minimize power drain from connected devices.
Digital Audio Remaster
Previously only found in Astell&Kern digital audio players, the HC4 is equipped with Digital Audio Remaster (DAR) technology. DAR technology is used 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 analog-like original sound, allowing you to enjoy the richness of the original sound, hear subtle differences in the nuance of the music and provide richer sounds at a higher level. The DAR slide key on the side of the AK HC4 provides an easy way to enable the DAR function directly from the device.
While modern smartphones, tablets, and computers support UAC 2.0 connections, many gaming devices still exclusively support UAC 1.0 connections. The AK HC4 ensures compatibility with any source by supporting both UAC 2.0 and UAC 1.0 connections for cross-platform quality sound experiences.
Now gamers can connect the AK HC4 to their favorite gaming devices such as a PlayStation or Nintendo Switch to enjoy low latency and enhanced, audiophile sound for an immersive gaming experience.
Accessories
To ensure compatibility with both Android and iOS devices without the need for additional adapters, the AK HC4 includes two interchangeable cables that support USB Type-C and Lightning connections. The cables are dual shielded cables to minimize 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. The cable is then wrapped in an aluminum film to block noise with an extra layer of shielding around the power cable to further minimize noise, the biggest issue in audio.
The tin-coated copper wire is then woven to further minimize noise interference. Finished with a fabric jacket on top of the TPE jacket, the cable features enhanced durability and usability with perfect aesthetic appeal.
Design
While small in size, the AK HC4 inherits the same design philosophy found throughout Astell&Kern’s product lines – Light and Shadow, through simple, yet delicate design elements.
The AK HC4 adopts a unibody structure, creating a smooth and clean appearance to the device. The front edge line is designed to be symmetrical left and right so that the line is gathered in the center, creating a balanced look that naturally focuses the gaze to the center of the device.
The side of the AK HC4 features concave lines, making it easy and comfortable to use in a form naturally tailored to be held in your hand. The keys on the side are either lifted at both ends or divided into dot embossed details, allowing the user to easily control function without looking, just by touch of the fingertips.
A LED indicator on the front of the AK HC4 displays song details and USB Audio Class (UAC) status.
The AK HC4 is certified Roon Tested.
Comparison
| AK HC3 | AK HC4 | AK HB1 | |
| MSRP | $229 | $220 | $259 |
| Color | Dark Gray | Moon Silver | Shadow Black |
| Body | Aluminum | Aluminum | Polycarbonate (Body) / Aluminum (Volume Wheel) |
| DAC | ES9219MQ x2 (Dual-DAC) | AKM AK4493S | ESS ES9281AC PRO |
| Sample rate (PCM) | PCM: up to 32bit/384kHz | PCM: up to 32bit/384kHz | PCM : 8kHz ~ 384kHz (8/16/24/32bits per Sample) |
| Sample rate (DSD Native) | DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo / DSD256(1bit 11.2MHz), Stereo | DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo / DSD256(1bit 11.2MHz), Stereo | DSD64(1bit 2.8MHz), Stereo / DSD128(1bit 5.6MHz), Stereo / DSD256(1bit 11.2MHz), Stereo |
| Output level (Unbalaced) | 2Vrms | 2Vrms | 2Vrms |
| Output level (Balanced) | – | 3Vrms (Condition No Load) | 4Vrms (Condition No Load) |
| Input | USB Type-C (Supports UAC 1.0 and UAC 2.0) | USB Type-C (Supports UAC 1.0 and UAC 2.0) | USB Type-C (Supports UAC 1.0 and UAC 2.0) |
| Output (Unbalanced) | 3.5mm (CTIA standard 4-pole supported) | 3.5mm (CTIA standard 4-pole supported | 3.5mm (CTIA standard 4-pole supported |
| Output (Balanced) | – | 4.4mm (Only 5-pole supported) | 4.4mm (Only 5-pole supported) |
| Bluetooth Chip | – | – | Qualcomm CSR8675 |
| Codecs / Profile | – | – | Bluetooth 5.0, LDAC, aptX HD, aptX, AAC, SBC A2DP, AVRCP, HFP |
| Frequency Response (Unbalanced) | ±0.013dB (Condition : 20Hz~20kHz) ±0.020dB (Condition : 20Hz~70kHz) | ±0.062dB (Condition : 20Hz~20kHz) ±0.066dB (Condition : 20Hz~70kHz) | ±0.135dB (Condition : 20Hz~20kHz) |
| Frequency Response (Balanced) | – | ±0.063dB (Condition : 20Hz~20kHz) | ±0.136dB (Condition : 20Hz~20kHz) |
| SNR (Unbalanced) | 118dB @ 1kHz | 118dB @ 1kHz | 117dB @ 1kHz |
| SNR (Balanced) | – | 118dB @ 1kHz | 118dB @ 1kHz |
| Crosstalk (Unbalanced) | -130dB @ 1kHz | -134dB @ 1kHz | -112dB @ 1kHz |
| Crosstalk (Balanced) | – | -136dB @ 1kHz | -112dB @ 1kHz |
| THD+N (Unbalanced) | 0.0005% @ 1kHz | 0.0005% @ 1kHz | 0.0005% @ 1kHz |
| THD+N (Balanced) | – | 0.0009% @ 1kHz | 0.0005% @ 1kHz |
| IMD SMPTE (Unbalanced) | 0.0002%, 800Hz 10kHz (4:1) | 0.0005% 800Hz 10kHz (4:1) | 0.0003% 800Hz 10kHz (4:1) |
| IMD SMPTE (Balanced) | – | 0.0004% 800Hz 10kHz (4:1) | 0.0003% 800Hz 10kHz (4:1) |
| Output Impedance (Unbalanced 3.5mm) | 2 ohm | 0.9 ohm | 2.5 ohm |
| Output Impedance (Balanced 4.4mm) | – | 1.6 ohm | 2 ohm |
| Dimensions (WxHxD) | 12.5 x 21 x 8.7 mm | 29.5 x 64.5 x 14.5 mm | 39.8 x 68.4 x 16.5 mm |
| Weight | 0.71 oz. (20g) | 1.09oz (31g) | 1.41oz (40g) |
Price & Availability
The Astell&Kern AK HC4 USB DAC will be available for $220 at authorized Astell&Kern dealers worldwide in December 2023.
Related Reading
ORT
November 21, 2023 at 3:20 am
And hast thou slain the Blabberwonk?
Let song come to my ears, no longer filled with the lie!
Oh frabjous day! Callooh! Callay!
The World is free of MQA!
Good riddance say I…
ORT
Ian White
November 21, 2023 at 11:36 am
ORT,
I know some additional details about the MQA situation. Email me privately.
IW