Astell & Kern PA10: Class A portable headphone amplifier

Astell & Kern has released the first in its range of portable headphone amplifier PA10 , working in class A.

Interestingly, the amplifier is designed exclusively for working with an analog signal, there is no DAC section in it. To connect to an external source, you can use an unbalanced input 3.5 mm or balanced 4.4 mm, headphone outputs are organized on identical jacks. The amplifier circuit is made according to the Teraton Alpha proprietary topology, the output stages operate in class A.

The device is housed in a rugged aluminum and silicon housing measuring 73 x 140 x 23.3 mm and weighing 325 grams . In the upper corner is a rotary volume control. The amplifier has a switchable gain ( Low Gain and High Gain ) and the output impedance does not exceed 1.3 Ohm . The maximum output voltage level on a 4.4mm balanced jack is 6.2V .

The built-in battery has a capacity of 4200 mAh and provides the amplifier for 12 hours with an unbalanced connection and a volume level of 30%.

The Astell & Kern PA10 headphone amplifier sells for US $550 in the US market .

Specifications of the Astell&Kern PA10 headphone amplifier:

• Analog Inputs: 3.5 mm unbalanced / 4.4 mm balanced
• Headphone outputs: unbalanced 3.5 mm / balanced 4.4 mm
• Maximum input level: 2V RMS (unbalanced input) / 4V RMS (balanced input)
• Output Level (Low Gain): 2.1Vrms (unbalanced input) / 4.2Vrms (balanced input) – no load
• Output Level (High Gain): 3.1Vrms (unbalanced input) / 6.2Vrms (balanced input) – no load
• Frequency Response: Low Gain ±0.2dB (20Hz-20kHz), High Gain ±0.06dB (20Hz-20kHz)
• Signal-to-Noise Ratio: Low Gain 111 dB @ 1 kHz (Unbalanced) / 115 dB @ 1 kHz (Balanced), High Gain – 114 dB @ 1 kHz (Unbalanced) / 117 dB @ 1 kHz (Balanced)
• THD: Low gain – 0.0045% @ 1kHz (single-ended) / 0.0015% @ 1kHz (balanced) High gain – 0.0027% @ 1kHz (single-ended) / 0.0013% @ 1 kHz (balanced path)
• Channel separation: -83dB @ 1kHz (unbalanced) / -110dB @ 1kHz (balanced)
• Output impedance: 1.1 ohm (3.5 mm unbalanced output) / 1.3 ohm (4.4 mm balanced output)
• Dimensions (W x H x D): 73 x 140 x 23.3 mm
• Weight: 325 g