Luxman L-550AX Mark II: Powerful amplifier made in Japan

Luxman L-550AX Mark II is a modified version (Mark 2) of the L-550AX amplifier, released in 2011. The Luxman L-550AX Mark II integrated stereo amplifier is made in Japan and is part of the X series of Luxman, whose models are designed for the most demanding music lovers. The amplifier operates in pure Class A, and is made using the highest-quality components, as well as a number of Luxman proprietary technologies.

Externally, the Luxman L-550AX Mark II looks simply gorgeous. The thick front panel made of brushed aluminum is decorated with a pair of large output power indicators, the backlight of which can be turned off if desired. The amplifier provides tone controls for low and high frequencies, stereo balance, and a switch for two pairs of speaker systems. The power supply uses a transformer of the same design as in the company’s top power amplifiers. The total capacity of the source filter capacitors is 40,000 μF. The device develops 20 W per channel when connecting 8 Ohm speakers, and 40 W when working on 4-ohm speakers. There are no “complex” speaker systems for the Luxman L-550AX Mark II, and it is capable of fully pumping up even large floor models.

The patented electronically controlled volume control circuit provides smoothness of the signal level change characteristic in the absence of interference and interference, as well as minimal distortion at any value. The constant output impedance of the controller has a positive effect on the stability of the following stages. Another proprietary technology used in the Luxman L-550AX Mark II, ODNF (Only Distortion Negative Feedback) version 3.0, is a negative feedback designed to reduce the level of nonlinear distortion without affecting other characteristics of the amplifier.

The Luxman L-550AX Mark II amplifier has a built-in phono preamplifier for MM and MC pickups, four linear unbalanced and one balanced inputs, an input/output for connecting a recording device, an output from a preamplifier and a “direct” input of a power amplifier, a headphone output. Reliable screw connectors in transparent housings for acoustic systems are lined up “in a line” at the very bottom of the rear panel, which greatly simplifies the connection of cables.

Specifications of Luxman L-550AX Mark II 

Output power 2 x 20 W (8 Ohm); 2 x 40 W (4 Ohm)
Input Sensitivity/Impedance 180 mV/47 kOhm (RCA Line), 180 mV/55 kOhm (XLR Line), 450 mV/47 kOhm (Main In) 2.5 mV/47 kOhm (MM Phono), 0.3 mV/100 Ohm (MC Phono)
Output Voltage 1 V (Pre Out), 180 mV (Record Out)
Frequency Response 20 Hz – 100 kHz (+ 0, – 3 dB, Line In), 20 Hz – 20 kHz (± 0.5 dB, Phono)
Harmonic Distortion Less than 0.007% (1 kHz, 8 Ohm), Less than 0.02% (20 Hz – 20 kHz, 8 Ohm)
Signal-to-noise ratio more than 105 dB (line input), 91 dB (MM phono equalizer), 75 dB (MC phono equalizer)
Damping factor 200
Tone control Bass: ± 8 dB, 100 Hz; HF: ± 8 dB, 10 kHz
Volume control precision 88-step electronically controlled LECUA1000 attenuator (Luxman Electric Controlled Ultimate Attenuator)
Inputs balanced XLR (with phase invert button), 4 line RCA, MM / MC phono preamplifier connectors (RCA), Monitor (RCA) connectors for recording control, Main In (RCA) for direct access to the final section
Outputs 6.3 mm for headphones, for recording (RCA), Pre Out (RCA)
Other switching ground terminal
MM / MC phono preamplifier with infrasonic filter yes
Loudness compensation yes, activated from the remote control
Internal wiring using OFC copper cable yes
Speaker output 4 pairs of screw terminals
Power supply massive EI-shaped transformer (470 VA), 4 capacitors with a total capacity of 40,000 μF
Remote control RA-17A, can work with Luxman CD players
Power consumption 230 W; 170 W without signal; 0.4 W in standby mode
Dimensions (WxHxD) 440x178x454 mm
Weight 24.3 kg