Beneath the elegant shell of a Luxman amplifier, lies innovative circuitry, meticulous attention to detail and plain common sense.
Using trickle down technology from the flagship B-1000f, comes this stereo Class A power-house amplifier, with pure A 60W x 2 per channel, into 8Ω. It is stable driving any loudspeaker, even 1Ω loads, with 480 watts to spare.
Luxman’s emphasis is on reproducing natural music, with lots of warmth, detail; not frightening it into scaring up non-existent detail, which is sometimes described as etched. Luxman’s engineers are fanatical in their attention to detail; while they spend a lot of time analyzing how components perform on their test equipment, the final arbiter is the listening evaluations. Is the product able to play music, convey the emotion, reproduce the ambiance of the venue as well as the timber of each instrument, distinctly? This is where Luxman shines.
Power amplifier assembly with 16 Bi-Polar Transistor output devices mounted to large copper plate attached to the heat sink for even heat distribution.
There is a bridging switch on the rear panel (marked BTL or Bridge-Tied Load, there is also a BTL LED indicator between the meters) if you need more power & weight to your music. In monaural mode the M-800A delivers 240W into 8Ω or 960W into 2Ω. While there is no increase in current, the voltage is quadrupled. With so much power on tap, the dynamic swings are amazing. The improvement in micro-dynamics has to be heard to be believed; tonally fuller, more organic sounding. Small details that you never heard before in your favorite albums, will now be revealed. Pure Class A = Pure Music.
Because the transistors in a Pure Class-A amplifier are never switched off, there is obviously no crossover distortion (there is no crossover – where one transistor turns off, and the other supplies the load current). Notice the uninterrupted curve above on the right. The amplifier is always fully charged and ready to allow the music flow spontaneously, with a dynamic, fast response time, the music is rich and sweet.
Only Distortion Negative Feedback (ODNF)
Luxman’s patented ODNF circuitry has redefined the relationship between music signals and noise and does not use phase compensation or NFB loops in the music signal path, instead it accurately isolates distortion components to cancel them.
Luxman holds many patents for audio engineering, amongst them is the application of Global Negative Feedback to the output stage (1955), which while widely used throughout the audio industry, they no longer use themselves.
Luxman nowadays use a distortion reduction circuit called Only Distortion Negative Feedback (ODNF). This system works by isolating noise & distortion at the output from the music signal and sparingly applying negative feedback to suppress them. Conventional negative feedback systems can have an adverse effect on the music, introducing phase distortion. “The circuit features such an ultra-wide range, ultra- high slew rate and ultra low distortion that it does not use phase compensation for the music signal amplifying circuits.” This new technology also ensures that need for a DC servo circuit is alleviated, again improving sound quality.
Luxman has a tradition of having VU meters in all of their solid-state amps & integrated amps. Interestingly enough they have updated the monoblocks and stereo amps with a vertical, yellow display bar graph, that can be dimmed or turned off completely. The industrial design has also been modernized with smooth round corners and the heat sinks have been placed inside the chassis.
Gold-Plated, Peel Coat Circuit Boards
Printed Circuit Boards normally have a green coat (dye) that can be printed upon, so the manufacturer knows where to place the copper traces and where to insert the resistors & capacitors. Luxman’s designers don’t like the sound of the green dye. In their extensive research they found that it smears the sound, so instead they print onto a plastic peel coat and remove it once the traces and mounting holes are in place. Then the copper traces are gold plated to reduce resistance across the circuit, as well as eliminate copper’s corrosion over time.
Custom AC Inlet
In order for an amplifier to multiply the signal cleanly, it first needs to receive clean electrical power. Luxman views the AC input with great concern, just as serious listening tests are applied to the power cables, so too is the AC inlet built to rigorous standards. With the M-800A, the AC inlet starts with high purity brass which subsequently receives a non-magnetic nickel plating and finally gold-plating is administered in order to maintain a low resistance.
Line Phase Sensor
Here is a clever device found on the back of every Luxman powered product. You press the button and it will check the phase of the electricity it is receiving. If the AC outlet in the wall is incorrectly wired, meaning the live and neutral are swapped, a red LED will turn on to warn you. You only need to press it once, when you are installing a product to check that everything is in order. It’s a simple mistake, that occurs often, and one that can seriously undermine your listening enjoyment.
In the M-800A the output from the power transformer is connected directly to the copper bus bar. By eliminating connectors, the transmission of power does not suffer any impedance drop, and it also allows for a cleaner signal to the amplification circuits. A lower noise floor is easily noticed in a greater dynamic window.
Mechanical Grounding & Resonance Control
Mechanical grounding and resonance control are taken very seriously in order to allow the electrical circuits operate at their optimum. The cast iron feet are directly connected to the heavily dampened bottom board in order to minimize vibration being conducted throughout the chassis. Similarly Luxman tunes the chassis from a resonance perspective in order maintain pace and rhythm. The fasteners torque settings are carefully measured for the sonic optimum.
JPA-1500 Power Cord
High current, high copper purity, flexible power cord is supplied as standard equipment. Molded connectors will never come loose, nor ever short circuit.
Over Sized Speaker Binding Posts
These over-sized binding posts can be cinched down by hand on some of the large speaker cables without resorting to any hand tools. You will also notice that the wiring configuration when the amplifier is used as a Bridge Tied Load (BTL) monoblock is indicated in parenthesis.
Is clearly and intelligently laid out. The over-sized speaker binding posts will take both spades or bananas and are easy to tighten down by hand for a secure connection. The Mono switch on the upper left hand side is marked BTL (Bridge-Tied Load). The RJ-11 socket is for remote turn on / off, either from a Luxman control amplifier or from a Home Theater processor.