Luxman L-590AX

Fully Balanced, Pure Class A Integrated Amplifier

If you are looking for the performance of separates, but need something that takes up less space, consider the Luxman L-590AX integrated amplifier

Review of the Luxman 590-AX

Luxman's highest quality Pure Class A integrated amplifier, the L-590AX benefits from the extensive technologies developed for Luxman's world-leading, high-end separate components.

Luxman introduced the L-590A in 2005, since then they have celebrated our 80th anniversary with commemorative components that have reaffirmed Luxman's status at the pinnacle of high-end audio. In these latest integrated models, the gorgeous texture and three-dimensional performance of our original Class A amplifiers has been retained and further refined. For example, the amplifiers feature a new electronic selector switch, adopted from the input section of the C-1000f control amplifier; the internal circuitry has been revised to include customised OFC wiring and a high-speed Schottky barrier diode has been selected for the power source section; improvements that have notably enhanced the sound quality for greater musical enjoyment.

As Luxman’s highest quality Pure A integrated amplifier, the L-590AX has benefited from the extensive technology first developed in the more expensive separates such as Peel Coat circuit boards, gold plated AC inlets, power transformer’s direct connection to the copper bus bar, mechanical grounding, upgraded speaker binding posts, upgraded power supply. All of the less-used controls are hidden by a drop-down door, giving a clean, elegant look.  It is easily powerful enough to drive most speakers in a normal listening room.

High Quality Electronic Selector
Meanwhile the electronic selector switch from the C-1000f control amplifier was adopted for the input section, which has lowered channel crosstalk & increased channel separation. In addition, the circuitry was revised,  e.g., the internal OFC wiring material was customized, the high-speed Schottky barrier diode was selected for the power source section; polishing the sound quality in order to heighten music enjoyment.

Chassis
The Chassis of the L-590 A possesses superb vibration absorption in order to supress noise levels. The power transformer, electrolytic capacitors and amplifer output stage are laid out so as not to interefere with each other. To reduce intereference further, the block construction isolates each section using shielding panels, and extensive internal filtering to reject magnetic flux interference. 

Luxman Exclusive ODNF Circuitry
Luxman holds many patents for audio engineering, amongst them is the application of  Global Negative Feedback to the output stage, which while widely used throughout the audio industry, they no longer use themselves.

Luxman nowadays uses 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.

Electronic Volume Control
The integrated amplifiers have a motorised volume control, addressable from the remote control. The less devices in the signal path, the purer the sound, the cleaner the music. 

Updated Amplifier 
The amplifier section has not been ignored either; noise and distortion has been kept to a minimum with the introduction of ODNF version 2.2A. The deep, rich Class A tone is available here in Luxman’s most powerful Class A integrated amplifier.

Pure Copper Wiring 
Extensive listening was applied to the high purity, oxygen free copper (OFC) wiring which is used to transmit the signal throughout the amplifier. This wiring has a minimal audible signature and minimal electrical effect on the audio waveform. Linear wide bandwidth frequency response is achieved by the low measured values of both inductance and capacitance. The result, the cables do not color the sound, but pass it through, quickly. Phono & Headphone Amplifiers 

Enjoy the ability to play or record your LP collection with the built-in phono stage which accommodates both Moving Magnet and Moving Coil cartridges. There is also a high quality headphone amplifier, accessible from the front panel. The headphone output is taken from the speaker output,, assuring you of the highest fidelity. A subsonic filter is also easily accessible on the front panel in order to remove unwanted low frequency noise while you are listening to a record. A mono switch is also available for both loudspeaker setup as well as mono record playback. 

Two Pairs of Speaker Terminals
Large speaker terminals for driving two individual sets of speakers. At the turn of the speaker switch, it is possible to change between the two pairs of speakers easily. In addition, if the A+B function is used; Takasina capacitors are used to parallel the output which permits bi-wiring a single pair of speakers. The speaker outputs may also be turned off in case you wish to listen with headphones.

Large Power Meters 
The large-sized power meters, calibrated in decibels are easy to read even from a distance. The logarithmic compression system is easy to grasp and also how this applies to the music. The meters are calibrated from -60dB below full rated power to +3dB above rated power. An 8mm thick acrylic covers the meters, which are normally backlit, though the illumination may be turned off from the remote control.

Tone Controls 
Tone controls might seem like an anachronism in this day and age of minimalism, but they can be remarkably effective in bring to life a less than perfect music collection. We all have music gems in our collection that are sonically challenged. A lot of the early CDs are quite harsh sounding and the digital glare can be quite fatiguing. Reduce the treble slightly; your old favorite music will now be eminently listenable. Sit back relax, enjoy the music. When you want to bypass the tone controls, just engage the Line Straight switch.

Aluminium Remote Control 
The easy to use, intelligently laid-out, aluminum remote control has all of the primary functions of the L-590AII, including power on / off can be controlled from the comfort of your listening chair. Besides the electronic volume control, there is also a mute feature. The display meters’ back light can also be turned on / off from the remote control. 

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. Its a simple mistake, that occurs often, and one that can undermine your listening enjoyment.  It is this fanatical attention to detail that delivers such superior sound quality.

Compared to the L-550A-II 
While the power rating improvement, vis-a-vis the L-550A, might not seem like a lot at first glance 30W versus 20W into 8 ohms, power is not the only consideration, the power supply is a lot more robust and capable of driving much more difficult speaker loads at lower impedances. The L-590A has a lot more finesse and reproduces music exquisitely. Notes are delivered against a blacker background, as the noise floor is lowered, so too are dynamics enhanced. The texture of the music is further improved, as is the soundstage definition; close your eyes and you will want to reach out to touch the musicians.

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, 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. In the photo below you will notice that Peel Coat circuit boards are an off-white color.  It’s this fanatical attention to detail that delivers such superior sound quality.

Pre-Main Cable
A new short interconnect is installed at the rear of the L-590AII for connection between the respective functions of the pre- section and the power section. (in the L-550AII a short pin is installed). Because of this, it is possible to upgrade in the future to a separate system combining the L-590A with another power amplifier or control amplifier. 

Speaker Binding Posts 
The L-590A speaker binding posts are of a much higher quality than found on the L-550A,

Larger Power Supply 
The power supply has a much a much larger reservoir allowing it to deliver power into lower impedance loads. (L-590AII: 680VA and L-550AII: 540VA) or put it another way, at a difficult passage in the music, the 590 will not have to strain as much at a crescendo but effortlessly glide by.

Direct Connection
In the L-590AII 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
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 tune the chassis from a resonance perspective in order maintain pace and rhythm. The fasteners torque settings are carefully measured for the sonic optimum. 

AWARDS

• MJ TECHNOLOGY (Japan) - Technology Of The Year - Category Excellence Award
• Audio Accessory (Japan) - Audio Excellence Award
• STEREO (Japan) - Special Commendation (January 2008)
• SWING JOURNAL (Japan) -  Jazz Component Award - Best Integrated Amplifier Award 

Specifications: