Luxman C-03/M-03 Amplifier
Taken together, and they are so obviously 'made for each other' that I cannot see much of a market for them apart, the Luxman C-03 preamplifier and M-03 power amplifier combination will set you back £ 1,098. However for this sizeable outlay you get a powerful control centre that will do justice to any high-quality source signals and deliver up to 200 Watts-per-channel into any type of loudspeaker load. Externally and internally the signs of quality are everywhere to be seen, so that pride of possession is assured. The solid fascia panels have a handsome brushed metal finish in marked contrast to the ubiquitous black.
The C-03 has a fair number of controls reflecting its operational versatility, yet these are helpfully laid out and differentiated as to shape with discreet little lamps indicating the source selected, tape monitor mode and straight-through mode.
Basically there is provision for five source inputs, including Video 1 and 2 with switching for audio and video signals, perhaps from a VCR, LaserVision or CDV disc player, plus two tape playback inputs labelled Tape/DAT 1 and 2 (with related record output sockets). The phono input has an associated selector switch on the front panel giving a choice of two capacitance loading values for moving-magnet cartridges and three resistive values for moving coil. The recording selector either sends the selected source to all recorder outlets or permits dubbing (of video signals as well as audio) between two machines, in which case a normal source can be listened to while dubbing is in progress. As is common nowadays there is a 'straight' mode bypassing the tone controls, subsonic filter and balance control circuits for minimum signal losses or interference. However, rather unusually, this can be switched to operate in the phono chain as well as for Compact Disc. There is also a tone in/out bypass switch, mono/stereo switch and an output selector for the two pairs of output phono sockets, routing the signals to power amplifier A, B, A + B or headphones. The output impedance is relatively low (20 Ohms) which allows flexible operation of two stereo power amplifiers or pairs of active loudspeakers over long cable runs if desired. The volume control is a precision low-noise component and all phono connectors are gold-plated.
The output circuit operates in Class A, avoiding crossover distortion, with the so-called 'straight' modes for phono and CD taking the shortest possible wiring route. They even bypass the normal source selection buttons. There are separate regulated power supplies for the phono, tone control and video amplifier stages, with the volume control placed after the control amplifiers. Luxman have unfortunately fallen into line with the current Japanese fashion for daft names and incorporated what they call a STAR (Signal Transit for Accurate Response) circuit which, apart from its name, is a sensible provision of separate power and earth lines for each stage. Proper use of the fairly generous internal dimensions keeps a safe distance between mutually sensitive parts of the circuit.
The M-03 power amplifier is rated at 200 Watts-per-channel into 8 Ohms and is suitably massive, with huge vaned heat-sinks, each weighing 1.5kg, running along both ends of the chassis, and a power supply based around two 15,000 μF block capacitors for each channel. There is provision for combined (bridged) mono operation when the power rating becomes 480 Watts into 8 Ohms. This mode is called BTL (Balanced Transformerless) and must be deliberately selected on the rear panel, where a security plate has been fixed at the factory to hold the switch in its normal stereo position.
Separate left and right channel attenuators are situated on the front panel and there is also a two-channel digital display of peak power level in Watts. A switch gives a choice of 1 or 3 seconds hold-time for the peak reading to make for easier monitoring under various programme conditions or, if you find the display distracting, it can be switched off. The power reading is related to the nominal loudspeaker impedance value selected on a three-position switch on the rear panel (4, 6 or 8 Ohms). Heavy duty terminals are fitted for two pairs of loudspeakers and front panel switches select speakers A, B, A + B or both off. The handbook shows how it would be possible to operate the C-03 preamplifier into two M-03 power amps each in the BTL mono mode to provide a hefty 480 Watts-per-channel (neighbours, ears and loudspeakers permitting). How they performed
Testing and auditioning this C-03 and M-03 combination has been a confidence building experience. From switching on, when the precautionary muting circuit waits a full six seconds to make sure that no current surges can reach the loudspeakers, the music signals are handled with unstressful ease. Sound quality remains clean and wide-ranging at any listening level. Indeed I found a tendency to listen at higher levels than usual just because there was so much undistorted power in hand. The peak power indicators are not a particularly useful feature, except that they serve as a reminder of how little power we need most of the time in classical music until the big climaxes come along.
The M-03 is such a heavy unit and is so solidly encased that it might seem impervious to acoustic feedback problems. However, presumably allowing for the very high levels that might be met in professional monitoring situations, the designers have fitted substantial isolating feet and the system is mechanically very stable. The heat sinks do their job well too, keeping the amplifier very cool after many hours of use. Of more direct interest was the residual noise level, which was remarkably low. On line inputs with all volume controls at maximum, placing one's ear close to the loudspeakers produced total silence. A smooth hiss was just audible at full volume on the phono input but this too disappeared at any practicable volume setting. Similarly, breakthrough between inputs was completely absent.
The switched loading on the phono input is a good idea. I wonder how many people are making do with over-bright or dim LP reproduction because it would be so fiddling to alter the loading for a better impedance match to their particular cartridge. Here, although the alternative loadings are so few, it becomes the work of a moment to decide on the best setting-always provided you are willing to trust the evidence of your ears. The 'straight' connection for phono and CD can also be checked out very simply. The effect of eliminating relatively short lengths of internal wiring is of course subtle and may be hard to detect on some musical material. However I found that choosing a passage where dynamics are important made many of my LPs and CDs take on a greater feeling of real excitement in the 'straight' mode.
Luxman's established reputation for designing and building high class amplifiers has perhaps rested mainly on their most elevated models such as the Prestige series. Now this C-03/M-03 combination shows what they can achieve at just over £ 1,000: fine appearance, well engineered operational features and genuine high-fidelity sound.
