Astell&Kern PA10

Astell&Kern PA10 – Portable Class-A Headphone Amplifier

The Astell&Kern PA10 is the manufacturer's first portable Class-A headphone amplifier, designed to make Astell&Kern's characteristic analog sound signature accessible on the go. By combining classic Class-A amplification, the proprietary TERATON ALPHA technology, and flexible control of gain and amplifier current, the PA10 is aimed at discerning listeners who want to complement their mobile player or DAC with a powerful analog amplifier.

Despite its compact format, the PA10 is designed to confidently drive both sensitive in-ear monitors and more demanding headphones. At the same time, the amplifier remains flexible enough to be used with a wide variety of source devices.

Class-A Amplification for Natural Sound

Class-A amplifiers have always been considered the benchmark for particularly linear and natural sound reproduction. They operate continuously in the active operating range, thus avoiding crossover distortions that can occur with other amplifier classes. The result is a soundstage that many listeners perceive as particularly smooth, harmonious, and authentic.

Traditionally, Class-A circuits are difficult to implement in portable devices due to their high power consumption. With the PA10, Astell&Kern applies its expertise in amplifier design for the first time to a portable Class-A headphone amplifier that nevertheless offers practical battery life.

TERATON ALPHA – Astell&Kern's Audio Technology

Inside, Astell&Kern's proprietary TERATON ALPHA technology optimizes various aspects of signal processing. This includes:

• efficient power supply and power management
• reduction of mains and circuit noise
• stable signal amplification
• optimized output circuit

The goal of this architecture is to amplify the audio signal as unadulterated and detailed as possible, without introducing additional distortion.

Class-A Current Control – Adaptation to Different Headphones

A special feature of the PA10 is the three-stage control of the Class-A amplifier current. The user can choose between Low, Mid, and High to adapt the amplifier's behavior to different headphones and IEMs.

This setting not only affects the power output but also the character of the Class-A amplification, allowing for finer tuning between dynamics, spatiality, and power consumption.

Gain Control for Optimal Performance

In addition to current control, the PA10 features a gain switch (Low / High). This allows the amplifier to be used with both very sensitive in-ear monitors and power-hungry headphones.

When using the balanced input, the PA10 achieves an output voltage of up to 6.2 Vrms, enabling powerful and controlled reproduction.

True Balanced Design with 4.4 mm Connection

Many portable amplifiers internally convert an unbalanced signal into a balanced signal. The PA10 takes a different approach and offers true balanced signal routing via 4.4 mm input and output.

This keeps the signal completely balanced throughout processing, which minimizes signal loss and enables higher output power.

Additionally, 3.5 mm inputs and outputs are available for unbalanced connections.

Hardware Crossfeed for More Natural Listening

The integrated hardware crossfeed mixes a small portion of the left and right channels in a controlled manner. This technique can make the perception of the stereo soundstage feel more natural and reduces the extreme channel separation often found in headphones.

Design and Portability

The PA10 adopts Astell&Kern's characteristic SLOPE design language, which is characterized by striking lines and high-quality craftsmanship. Despite the powerful Class-A circuit, the device remains compact enough for mobile use.

The integrated battery allows for a playback time of up to approximately 12 hours, and charging is conveniently done via USB-C.