Усилители для наушников — Lehmann Audio Traveller

The Traveller is the first portable headphone amplifier from Lehmannaudio, the Cologne maker that started in 1988 as Entec and is better known for its Linear desktop units and Black Cube phono stages. It was introduced in 2014 and is intended for use at home, in the office or while travelling, fed by any player with an analogue output. The signal stays fully analogue from input to headphone socket, with no converter or digital processing inside. British buyers paid GBP 400 at launch. In size it roughly matches the Astell and Kern AK100 and AK120 portable players.

Key specs that matter

Output is 120 mW into 33 ohms and 12 mW into 330 ohms, with a 3 ohm output impedance. Maximum gain is 10 dB. Response runs from 20 Hz to 30 kHz within 0.5 dB. Distortion is below 0.02% at 3 mW into 330 ohms, noise is more than 95 dB down (RMS unweighted, 0 dB gain), channel separation is better than 80 dB at 10 kHz, and tracking error between channels stays under 0.3 dB. Input impedance is 47 kohms. The body measures 80 x 90 x 25 mm and weighs 196 g.

Engineering and use context

A lithium polymer cell of 3.7 V and 4,000 mAh gives more than 20 hours per charge, depending on volume. It charges over a Micro-USB socket at 500 mA, which takes about six hours from empty. Voltage gain comes from parts by Analog Devices and Burr-Brown, and the output stage is discrete with no global feedback. Volume is handled by a microprocessor that switches a passive resistor network, so level steps stay precise even at very low settings. Two small buttons raise and lower the level, balance is adjusted through the same buttons, and the last setting is restored when the unit is switched on again. The case combines brushed metal with a soft-touch front panel.

Pairing

Two 3.5 mm stereo minijacks handle line input and two more carry the headphone or line output, with sockets on both the front and rear panels. The line output lets the Traveller act as a preamp for active loudspeakers. The low output impedance and the 33 ohm power rating favour low-impedance portable headphones, and the manufacturer states that it also drives demanding headphones. The box contains an operating manual, a USB cable for charging from a computer and a short minijack-to-minijack lead for connecting a player.

Alternatives

Lehmannaudio makes no other portable headphone amplifier, so the nearest model is the mains-powered Linear SE from its home range.