Astell&Kern AK PA10 Amp Portable Class A Amplifier for A&K Hi Res Audio Players

The Astell&Kern AK PA10 is a portable Class-A headphone amplifier featuring 4.4mm true balanced and 3.5mm unbalanced inputs and outputs, three-step Class-A current control, and up to 6.2Vrms balanced output. It is the first portable Class-A amplifier from Astell&Kern, built around their proprietary TERATON ALPHA technology.

Key specifications

• Amplifier: Class-A with three-step current control (High / Mid / Low)
• Inputs and outputs: 3.5mm unbalanced, 4.4mm true balanced
• Output level (high gain): 3.1Vrms unbalanced, 6.2Vrms balanced (no load)
• Output level (low gain): 2.1Vrms unbalanced, 4.2Vrms balanced (no load)
• Gain: high / low, plus hardware crossfeed
• Recommended headphone impedance: 16–300 ohms
• Battery: 4,200mAh, approximately 12 hours playback
• Charging: USB-C, approximately 3 hours with fast charging
• Weight: approximately 325g

Portable Class-A Amplifier AK PA10

The AK PA10 is Astell&Kern's first portable Class-A amplifier, combining Class-A AMP circuit design with their proprietary TERATON ALPHA technology to deliver natural, spacious analogue sound from digital audio players and other source devices.

• Class-A AMP with current control (High / Mid / Low)
• Gain control (High Gain / Low Gain)
• 4.4mm true balanced input/output
• 3.5mm unbalanced input/output
• Hardware crossfeed
• Up to 12 hours playback
• Power and battery indicator
• USB-C charging
• Astell&Kern SLOPE design

Distortion-free Analogue Sound of Class-A AMP

Class-A amplifiers amplify signals without clipping or crossover distortion, producing soft, warm, and natural sound. They are widely regarded as the preferred amplification method for critical listening, but their high power consumption has traditionally made them impractical in portable devices.

The AK PA10 uses a unique Astell&Kern circuit design that reduces power consumption and increases output while minimising noise, making true Class-A amplification viable in a portable form factor.

Class-A Current Control – Intense and Spatial Sound

The AK PA10 offers three-step Class-A current control to suit different headphones and IEMs, allowing you to tailor the intensity and character of the sound to your transducers. Controlling the current value also manages power consumption — the key reason Class-A amplification has historically been avoided in portable devices.

* [Low] Default / [Mid] +50mA / [High] +100mA

Vivid Sound Output of Gain Control

The AK PA10 supports two gain levels to suit a wide range of headphones and IEMs. At high gain with balanced input, output reaches 6.2Vrms, ensuring sufficient drive for demanding transducers.

* [Low Gain] Unbalanced 2.1Vrms / Balanced 4.2Vrms (Condition No Load)

* [High Gain] Unbalanced 3.1Vrms / Balanced 6.2Vrms (Condition No Load)

4.4mm In/Out True Balanced Circuit Design

Many portable headphone amplifiers convert 3.5mm unbalanced signals to 4.4mm balanced, or omit 4.4mm balanced support entirely — both approaches degrade signal integrity. The AK PA10 supports a true 4.4mm balanced input and output, preserving the full balanced signal path from source to headphone. 3.5mm unbalanced input and output are also supported for broader device compatibility.

* Output is available for the same size as the input terminal. Ports cannot be mixed (e.g. 3.5→4.4 / 4.4→3.5).