Интегральные усилители — Luxman L550AXII

The L-550AXII is the Mark II version of the mid-range pure Class A stereo integrated amplifier from Luxman. The update brings in circuit technology equivalent to the higher grade L-590AXII, including version 4.0 of the ODNF feedback circuit, the LECUA1000 computerized attenuator and a discrete buffer circuit as standard.

Key specs that matter

Rated output is 20 W per channel into 8 ohm and 40 W per channel into 4 ohm, all in pure Class A. Total harmonic distortion measures 0.007% or less at 1 kHz and 0.02% or less from 20 Hz to 20 kHz into 8 ohm. Signal to noise is 105 dB for line, 91 dB for MM phono and 75 dB for MC phono. Damping factor is 200. Line frequency response extends from 20 Hz to 100 kHz (+0, -3.0 dB), and the phono section covers 20 Hz to 20 kHz within 0.5 dB. There are four RCA line inputs at 180 mV and 47 kohm, one balanced XLR input at 180 mV and 55 kohm, and a phono input for MM (2.5 mV, 47 kohm) or MC (0.3 mV, 100 ohm). A main-in (450 mV), a record out (180 mV) and a pre-out (1 V) complete the connections.

Engineering and use context

ODNF 4.0 improves the high-frequency distortion behaviour of Luxman's own feedback system. The LECUA1000 adjusts volume in 88 steps and is laid out on a three-dimensional substrate. The discrete buffer circuit matches the one in the top-tier C-900u preamplifier. Power comes from an EI core transformer with vibration control feeding a block of four 10,000 uF capacitors. Speaker relays with low impedance are wired in parallel to raise the damping factor. Bass and treble shift by 8 dB at 100 Hz and 10 kHz, and a balance control and loudness function are included. A pointer-type meter with LED lighting sits on the redesigned front panel. Supply versions exist for 230 V at 50 Hz and 115 V at 60 Hz. Consumption is 230 W in use, 170 W at idle and 0.5 W on standby. The chassis is 440 x 178 x 454 mm and weighs 24.3 kg.

Pairing

The MM/MC phono stage accepts a turntable directly, and a front headphone jack covers private listening. The single XLR socket takes a source with balanced connections. The pre-out and main-in make it possible to use only the control section or only the power section, and plastic caps are supplied for any unused sockets. An RA-17A remote comes in the box.

Alternatives

The Luxman L-595ASE is a limited edition pure Class A integrated amplifier built in a run of 300 units for the 95th anniversary.