Усилители для наушников — EarMen CH-Amp

The CH-Amp is a desktop headphone amplifier and preamplifier from EarMen, balanced from input to output. EarMen was spun off from the Serbian high-end maker Auris Audio and designs its products in Europe for production in Serbia. The amplifier ships with the external PSU-3 linear power supply, and at launch the pair carried a list price of USD 1,480. EarMen later followed it with the CH-Amp Signature, which adds conversion and wireless input.

Key specs that matter

Maximum output into 32 ohms is 3.8 W from the balanced 4.4 mm socket in high gain, falling to 0.95 W in low gain. The single-ended 6.35 mm socket gives 1.5 W in high gain and 0.26 W in low gain. Measured voltage swings are 11 V and 5.5 V balanced, 7 V and 2.9 V single-ended. THD+N stays between 0.0005% and 0.0008% depending on input and output, signal-to-noise ratio ranges from 116 dB to 119 dB with circuit and gain, and frequency response deviates by only 0.005 dB. Headphone output impedance is below 1 ohm on both jacks. The amplifier measures 150 x 30 x 150 mm and weighs 550 g.

Engineering and use context

EarMen builds the circuit around a composite amplifier topology, which combines stages chosen for DC precision with stages chosen for AC behaviour. Parts include SoundPlus OPA1642 operational amplifiers, WIMA film capacitors, audio-grade electrolytics and MELF low-noise resistors. Inputs are two RCA pairs plus one 4.4 mm Pentaconn balanced socket. At the rear, an RCA pre-out and a 4.4 mm balanced line output turn the unit into a preamplifier, with line output impedance of 100 ohms single-ended and 200 ohms balanced. An OLED display, a digital volume knob that also handles power and mute, a front gain button and a rechargeable infrared remote complete the controls. Cooling is passive through a vented base. The PSU-3 box measures 150 x 60 x 150 mm, weighs 1,590 g, switches between 115 V and 230 V mains, and offers four 12 V outlets protected against overload, overheating and short circuit.

Pairing

The balanced output with its large voltage reserve suits planar and high-impedance dynamic headphones, while low gain keeps the volume range usable with sensitive models. A DAC with balanced or RCA outputs feeds it directly, and the spare PSU-3 outlets can power up to three further EarMen devices such as a matching DAC. Powered monitors connect through the preamp outputs.

Alternatives

For a single box with a built-in ESS9038 USB DAC and Bluetooth input, EarMen offers the CH-Amp Signature as its successor.