Усилители для наушников — Lehmann Audio Linear II Pro

The Linear II Pro comes from Lehmannaudio in Cologne, Germany, placed in the studio and stage range of the maker. It is derived from the home Linear model and adapted for recording and mastering rooms, where it takes a balanced line feed and drives two pairs of headphones at once.

Key specs that matter

Output power is 400 mW into 60 ohm and 200 mW into 300 ohm per channel. Four gain settings of 0, 10, 18 and 20 dB are chosen with DIP switches inside the unit. Frequency response extends from 10 Hz at -0.3 dB to 35 kHz at -1 dB, while noise stays more than 108 dB down with gain at 0 dB. Lehmann quotes THD of 0.003% at 13 mW into 300 ohm, channel separation above 70 dB at 10 kHz and channel mismatch below 0.3 dB at full volume. Output impedance is 5 ohm and maximum output level is +20 dBu. Input impedance of the balanced stage is 18 kohm. The chassis measures 110 x 280 x 50 mm (width, depth, height), weighs 1.5 kg net and draws about 10 W from the mains.

Engineering and use context

The input is a stereo balanced stage built for high headroom so that hot studio levels do not overload it, and Neutrik combo sockets with gold-plated contacts accept both XLR and jack plugs, which lets balanced and unbalanced sources be connected. The two headphone outputs are Neutrik 6.35 mm sockets with gold-plated contacts wired in parallel from a discrete class A transistor output stage, so both listeners should use headphones of the same impedance. The narrow aluminium housing comes in a silver or a black anodised version. The front panel carries only the volume control and the two jacks, which keeps operation simple in a studio rack. Lehmann also sells a Low-Z copper analogue board upgrade from EUR 499 and optional 3S device feet for EUR 99.

Pairing

Typical sources are a mixing console, an audio interface or a studio converter feeding balanced lines, and the switchable gain lets the level be matched to low-impedance closed monitors or high-impedance open studio headphones. The low output impedance keeps the damping factor high even with 32 ohm models. In a home system the unit can equally sit after any line-level source through the combo inputs with standard RCA to jack leads. The parallel outputs are useful in a control room where an engineer and a performer or producer need to hear the same mix at the same time.

Alternatives

The Lehmannaudio Linear USB II is a home headphone amplifier in the same slim case with an ESS Sabre DAC and a USB input built in.