The Luxman L-507uX is a fully featured integrated amplifier conceived and created like a sophisticated separate to deliver highly accurate sound reproduction. Internally, the L-507uX is divided into blocks to reject radio-frequency noise; thereby improving the audible signal-to-noise ratio. While the power amp, power supply in/output and display blocks are shielded extensively and circuits are carefully isolated from each other to drastically cut interference due to magnetic flux. This design also helps make the chassis more rigid, coupled with ideal weight distribution to cut noise and vibration.
With the multimedia age, the number of available audio sources – both analog and digital has risen dramatically. To handle such a wide array of inputs, Luxman gave the L-507uX a total of nine inputs (including 2 x balanced) a wonderful new phono-stage, tone controls (easily defeated at the touch of a button), enough power to drive most speakers in just about any room in your home and a remote control to add convenience to a remarkably comprehensive integrated amplifier.
Luxman L-507uX Integrated Amplifier Features
LECUA Volume Control
The Luxman L-507uX has a discrete volume control based on the C-1000f preamplifier design—no moving parts, no tracking issues at any volume setting. Much more transparent sounding and will sound the same at every level. This is the most important of all the upgrades and the most expensive to implement, as the individual resistors need to be measured by hand.
The ODNF circuitry has been incorporated into the LECUA PCB so that the module can reject both radio frequency interference as well as electro-magnetic interference.
Luxman holds many patents for audio engineering—amongst them is the application of Global Negative Feedback to the output stage. And while still widely used throughout the audio industry, they no longer use it themselves.
Today, Luxman 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.
ODNF revision 3.0 analyses the music signal with three different passes and corrects either noise and/or distortion found in the music signal. The interesting thing is that it only effects that part of the music signal that is corrupt. A quieter amplifier has a lower noise floor and so has greater dynamic headroom; less noise, more musical information retrieved from deep inside the recording.
* ODNF is an abbreviation for Only Distortion Negative Feedback.
The L-550AX, L-590AX, L-505uX, and L-507uX, all feature a new high quality electronic selector switch, which is the heart of the C-1000f pre-amp (one of Luxman’s 80th anniversary commemoration models). The sound quality deterioration using the new electronic input switch is now minimal, while channel separation and crosstalk efficiency were raised substantially in comparison with the previous L-505f/L-507f/L-509f SE. In addition the illuminated position indicator around the input selector knob, makes it much easier to view the selected position even from afar.
The amplifier section has not been ignored either; noise and distortion has been kept to a minimum with the introduction of ODNF version 3.0. The deep, rich tone is well able to reveal subtle detail buried deep in the music, due to the removal of noise and distortion.
Pure Copper Cabling
Extensive listening was applied to the high purity, oxygen free copper (OFC) cables which are used to transmit the signal throughout the amplifier. These cables have 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.
Enjoy the ability to play or record your LP collection with the newly designed built-in phono stage which accommodates both Moving Magnet and Moving Coil cartridges. A subsonic filter is also easily accessible from the remote control 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.
The headphone output use the same circuitry as the speaker outputs; late night listening is so rewarding, treat yourself to the best headphones that you can afford – you will not be disappointed.
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 loudspeakers can also be turned off in case you rather listen to headphones.
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.
Easy to use, intelligently laid-out, aluminum remote control; all of the primary functions of the L-507uX, including power on / off, input selection 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.
The 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 challenging. A lot of the 1980’s CDs are quite harsh sounding and the digital glare can be quite fatiguing. Reduce the treble slightly and while the harsh CD is not going to suddenly sound like a reference recording, at least it will now be perfectly listenable. Sit back relax, enjoy the music & forget about the HiFi. When you want to bypass the tone controls, just engage the Line Straight switch.
NOTE: You might also use the Tone Controls for room acoustics’ correction. They are in effect simplified room equalization controls.