Astell&Kern AK-HC4

Astell&Kern AK HC4: A High-Resolution Portable Audio Converter

The Astell&Kern AK HC4 is a portable USB digital-to-analog converter (DAC) designed for a Hi-Fi audio experience with smartphones, tablets, and computers. As the successor to the HC3, this model features notable improvements such as the AKM AK4493S DAC, dual 3.5 mm and 4.4 mm headphone outputs, and Digital Audio Remaster (DAR) technology for refined analog sound.

Technical Features

AKM AK4493S DAC

To achieve the best possible audio quality with a USB DAC, the AK HC4 is the first in its category to integrate the AKM AK4493S DAC. Appreciated in Astell&Kern’s digital audio players, this component benefits from improved noise control, low-power design, and ultra-precise amplification technology. It supports native DSD up to DSD256 and PCM up to 32 bits/384 kHz.

Dual 3.5 mm and 4.4 mm Headphone Outputs

The AK HC4 features dual headphone outputs with 3.5 mm and 4.4 mm connectors, ensuring compatibility with most Hi-Fi headphones and earphones without requiring adapters. The balanced 4.4 mm output provides a high level of 3 Vrms to make the most of sensitive headphones and earphones, while ensuring clear channel separation and minimal noise. The unbalanced 3.5 mm output delivers 2 Vrms, sufficient for enjoying the full performance of your earphones.

Digital Audio Remaster (DAR) Technology

Previously reserved for Astell&Kern’s high-end digital audio players, the Digital Audio Remaster (DAR) technology is integrated into the AK HC4. It allows for upsampling the audio signal beyond the source format’s limits. This high sampling frequency offers a more refined reproduction and a delicate, analog-like original sound, restoring all the richness and subtle nuances of the initial recording. A DAR selector on the side of the product allows for easily choosing the upsampling options:

• PCM 44.1 kHz converted to 352.8 kHz
• PCM 48 kHz converted to 384 kHz
• DSD lower than DSD256 converted to DSD256

Extended Compatibility

The AK HC4 supports both UAC 1.0 and UAC 2.0 connections to accommodate a wide range of devices. While modern smartphones, tablets, and PCs are UAC 2.0 compatible, many gaming devices only support UAC 1.0. By managing both standards, the AK HC4 ensures a high-quality audio experience on all platforms. When connected to a gaming console like the PlayStation or Switch, it provides low latency and enhanced sound for optimal immersion.

The AK HC4 is also compatible with iOS devices thanks to the included USB-C to Lightning cable. A USB-C to USB-C cable is also provided for seamless connectivity with various sources.

Main Benefits of the Astell&Kern AK HC4

• Ultra high-resolution Hi-Fi sound with AKM AK4493S DAC
• Exclusive amplification circuit with enhanced noise control, low-power design, and ultra-precise amplification technology
• Digital Audio Remaster (DAR) technology for upsampling the signal beyond the source format limits
• Dual 3.5 mm and 4.4 mm headphone outputs for extended compatibility without adapters
• UAC 1.0 and 2.0 support for multi-platform compatibility, including gaming consoles
• Interchangeable cable (USB-C and Lightning included) for seamless connectivity with various sources
• Compact and sleek design with a robust aluminum housing
• Double-shielded cable to minimize noise and optimize sound quality
• LED indicator for convenient feedback
• Roon Tested certification for optimal integration with Roon software

Technical Specifications

Audio Components

• Digital-to-Analog Converter (DAC): AKM AK4493S
• PCM Sampling Rate: 8 kHz to 384 kHz (8, 16, 24, 32 bits per sample)
• Native DSD:
  • DSD64 (1 bit 2.8 MHz), stereo
  • DSD128 (1 bit 5.6 MHz), stereo
  • DSD256 (1 bit 11.2 MHz), stereo

Output Levels

• Unbalanced: 2 V RMS
• Balanced: 3 V RMS (no load)

Audio Performance

• Frequency Response:
  • Unbalanced: ± 0.062 dB (20 Hz to 20 kHz), ± 0.066 dB (20 Hz to 70 kHz)
  • Balanced: ± 0.063 dB (20 Hz to 20 kHz), ± 0.067 dB (20 Hz to 70 kHz)
• Signal-to-Noise Ratio:
  • Unbalanced: 118 dB at 1 kHz
  • Balanced: 118 dB at 1 kHz
• Crosstalk:
  • Unbalanced: 134 dB at 1 kHz
  • Balanced: 136 dB at 1 kHz
• Total Harmonic Distortion + Noise (THD+N):
  • Unbalanced: 0.0005% at 1 kHz
  • Balanced: 0.0009% at 1 kHz
• SMPTE Intermodulation Distortion (IMD SMPTE):
  • Unbalanced: 0.0005% 800 Hz 10 kHz (4:1)
  • Balanced: 0.0004% 800 Hz 10 kHz (4:1)

Output Impedance

• 3.5 mm Unbalanced Output: 0.9 Ω
• 4.4 mm Balanced Output: 1.6 Ω

Connectivity

• Input: USB Type-C (compatible with UAC 1.0, UAC 2.0)
• Outputs: 3.5 mm (unbalanced), 4.4 mm (balanced, 5 poles)

Physical Characteristics

• Color: Lunar Silver
• Material: Aluminum
• Dimensions (W × H × D): 29.5 × 64.5 × 14.5 mm
• Weight: approximately 31 g