TECHWEEK
The Luxman M-900u stereo power amplifier is yet another masterpiece from Japanese engineers at Luxman. The design of the model is made in the style of minimalism: clear and straight lines, an understandable control system and massive gradient supports that protect the device from unwanted vibration – this is what you may notice when you first look at the model.
Aesthetically, the Luxman M-900u power amplifier is made in a laconic retro style. The model boasts impressive power indicators, as well as the ability to work with any speaker system.
The Luxman M-900u amplifier has a massive 48 kg case with a front aluminum panel, in which two analog level indicators with original white LED backlight are built. On the front there is a power / standby button with indication of operating modes, an input selection button with two LEDs, a backlight off button and an LED diode indicating the activation of the BTL bridge mode. The amplifier chassis does not use a ground loop, which can introduce parasitic interference and noise. The cabinet has excellent damping and is supported by gradient cast iron feet to effectively damp resonances and vibrations.
The Luxman M-900u power supply is equipped with four 20,000 uF capacitors and a powerful transformer (1250 VA), the windings of which are made using rectangular wires. A thick bus of purified oxygen-free copper OFC runs from the PSU to the output stages. The unit develops a power of 150 watts per channel at 8 ohms, 2 x 300 watts at 4 ohms and can operate in BLT bridged mode, while delivering 600 watts (8 ohms). Up to 12 W Luxman M-900u works in class A. The Luxman M-900u amplifier has a damping factor of 710 units and is not afraid of a drop in load impedance up to 1 Ohm.
The amplifier has one block for each channel with four parallel push-pull amplification circuits. It uses Darlington circuits and ODNF (version 4.0) proprietary negative feedback technology, designed specifically for distortion suppression. The chains use premium components.
At the rear of the amplifier there are two inputs – balanced and unbalanced. One of the connectors of each input can be used to connect the Luxman M-900u in monoblock (bridge) mode, to which the corresponding “slider” is used. For balanced jacks, there is a phase inverting switch. There is a system bus port and a grounding lug. To connect the AC, the handpiece is equipped with two pairs of massive screw terminals.
Conclusion
The sound of the amplifier is characterized by openness, exceptional clarity, naturalness, rich natural highs and midrange, deep dense bass and a wide surround stage. The model will be an excellent companion for pairing with the Luxman C-900u preamp.
