Усилители для наушников — Luxman P-100 CENTENNIAL

Luxman built the P-100 CENTENNIAL as its top headphone amplifier to mark the 100th anniversary of the Japanese company. It is a solid-state design with four separate amplifier blocks, a fully balanced signal path and a new feedback engine that Luxman describes as the successor to a circuit it has used for more than two decades.

Key specs that matter

From the unbalanced output the amplifier delivers 4 W per channel into 8 ohm, 2 W into 16 ohm, 1 W into 32 ohm and 53 mW into 600 ohm. Balanced drive quadruples those figures, reaching 8 W into 16 ohm, 4 W into 32 ohm and 213 mW into 600 ohm, and instantaneous peaks go up to 5 W unbalanced and 20 W balanced into 8 ohm. Input sensitivity is 1.0 V at 14 kohm on RCA and 2.0 V at 28 kohm on XLR. The response is flat within 0.1 dB from 20 Hz to 20 kHz and reaches from 10 Hz to 175 kHz at the -3 dB points. Distortion at 1 kHz is 0.0025% unbalanced and 0.0015% balanced, while noise sits 117 dB and 119 dB below the reference level with IHF-A weighting. Luxman lists 67 W consumption in use and 47 W with no signal. The case is 446 x 136 x 401 mm and weighs 19.7 kg.

Engineering and use context

The LIFES feedback engine is an evolution of the ODNF circuit, and according to Luxman it cuts distortion by more than half and raises the signal-to-noise ratio by over 3 dB compared with the earlier approach. Volume is set by the LECUA-EX electronically controlled attenuator in 200 steps of 0.5 dB, with three input sensitivity settings, left and right balance and a six-stage volume limiter to protect headphones from accidental high levels. The four power amplifier blocks run in bridge-tied load configuration for balanced outputs. A 3-pin XLR terminal is reserved for a parallel BTL mode in which two units are linked for even more drive. Headphone sockets comprise a 6.3 mm jack, a 4-pin XLR and a 4.4 mm balanced jack. Power comes from two custom OI transformers, one for each channel, and a third EI transformer for peripheral circuits. The chassis rests on four cast iron feet with a density gradient.

Pairing

With several watts on tap into low impedances, the P-100 CENTENNIAL can drive low-efficiency planar magnetic headphones, and the balanced output's reserve into high impedances covers high-impedance dynamic models. Sources connect over either RCA or XLR, so a DAC with balanced outputs can stay balanced all the way to the headphone.

Alternatives

The Luxman P-750u is an earlier headphone amplifier from the brand that also uses LECUA volume control, ODNF 4.0 feedback and a BTL balanced output stage.