LUXMAN Control Amplifier C-10X

LUXMAN releases the latest model of control amplifier, the C-10X, in December 2023.
The C-10X is indeed the successor to the C-900u released in 2013, but is a completely redesigned amplifier. This new flagship model was developed with the aim of achieving the overwhelming audio quality that next-generation components should provide for the 100th anniversary of LUXMAN in 2025.

In the amplifier section, LUXMAN’s new LIFES amplification feedback engine, which was first adopted for the M-10X flagship power amplifier, is installed for the first time in a control amplifier. Four fully-balanced preamplifier blocks, under completely identical operating conditions, achieve pristine purity and a natural, three-dimensional sound.

LUXMAN’s original electronically controlled attenuator, LECUA, is directly connected to the preamplifier section, translating volume control operation into attenuation in fine increments of 0.5dB.

The rotary encoder system is driven by a stylish volume knob, with its built-in heavyweight damping mechanism, installed on the front panel.
The C-10X is equipped with LECUA-EX, which reproduces the feel of traditional audio equipment, but with modern technology under the hood, and achieves smooth and tactile volume control, while thoroughly suppressing sound quality deterioration. The exterior expresses a three-dimensional layering with a bold contrast between the authentic, blasted white finish front panel, inherited from the C-900u, and a fresh hairline finish top panel.

An exquisite combination of different finishes and shapes evokes a presence as a component, indicative of the richness, depth and delicacy within.
To attain its flagship pedigree, the C-10X control amplifier is a C-series model revision, the first in 10 years, with plenty of luxurious features unique to high-end products.
As the perfect partner to our M-10X power amplifier, it is equipped with our latest LIFES amplification feedback engine and as a controller, it draws out peak performance from any power amplifier, challenging the high expectations of audiophiles all around the globe.

By our innovation and imagination, we deliver the highest quality sound and listener satisfaction.

*LIFES stands for Luxman Integrated Feedback Engine System *ODNF stands for Only Distortion Negative Feedback *LECUA-EX stands for Luxman Electronically Controlled Attenuator – Excellent eXperience

LIFES (Luxman Integrated Feedback Engine System)

From ODNF to LIFES

Since its founding, LUXMAN has developed numerous amplifier circuits in order to achieve the highest performance and musicality required of high-end audio amplifiers.

ODNF (Only Distortion Negative Feedback) 1.0, which was first used in car audio amplifiers in 1999, achieved excellent static characteristics without feeding back the actual musical component of the audio signal to the main amplifier, providing natural distortion elimination, almost like a non-feedback equipped model.
As an epoch-making amplifier circuit that provides excellent sound quality, our system has steadily evolved up to its final version, ODNF-u, which debuted in 2020.
In 2021, in anticipation of the 100th anniversary, LUXMAN has completed work on a new amplification feedback system, “LIFES” , which has achieved even more realistic, fresh, rich musicality and overwhelming audio performance.
2023 will see it installed in our new flagship C-10X control amplifier.
LIFES 1.0

Simple, high performance

Our newly developed LIFES amplifier feedback engine greatly improves the static characteristics of the ODNF system and we have made improvements to the differential amplifier that detects distortion in the signal. Various approaches were considered at the design stage and, by adopting an N-channel dual JFET with excellent audio characteristics in the first stage of the differential amplifier, distortion detection accuracy was greatly improved. We succeeded in reducing the number of parallel elements that make up the circuit while improving performance and, by drastically changing the operation configuration of the entire amplifier, we effectively reduced distortion during amplification by 50%.

Improving constant voltage circuitry

In order to support delicate amplification operations that accurately convey all of the nuances in a music signal, the combination of a dual packaged control elements and improvements to the constant voltage circuitry contribute to stable operation, as did the adoption of US-made Zener diodes (Vishay), of course with the emphasis on audio quality. The new, highly stable power supply is resistant to input and output load fluctuations, AC and DC gain variations and has excellent regulation performance that faithfully supports reproduction of the finest musical details.

Improved response to environmental changes

For the purpose of stable operation, LIFES features four current mirror-type constant current circuits and dual transistors for each channel to thoroughly eliminate the effects of fluctuations in ambient temperature and power supply voltage in the listening room.
Furthermore, the temperature compensation of the current amplification stage combines a transistor and a thermistor to suppress bias fluctuations, improving the circuit for more stable operation.
LECUA-EX (Luxman Electric Controlled Ultimate Attenuator – Excellent eXperience)
Smooth and precise volume control with reduced sound quality deterioration
A volume control function is essential for audio amplifiers and it is necessary to have a mechanism that smoothly attenuates the voltage while maintaining the quality of the input source in order to output audio at a level suitable for listening on a fixed gain power amplifier. LUXMAN’s original LECUA is an electronically controlled attenuator system that switches independent, high-quality fixed resistor steps for each channel, arranged orderly on the circuit board according to the position of the volume control.
Since the release of our C-1000f control amplifier, the 80th anniversary model released in 2006, the “LECUA1000”, embedded in the amplifier circuitry, saw very little change in sound quality due to the influence of external vibrations affecting the volume setting. As a volume control system that does not deteriorate over time, it has been installed in many of our products.
The C-10X combines a high-precision rotary encoder with a newly developed heavyweight rotation mechanism to complete the “LECUA-EX” system, achieving even greater reliability and a natural, high-quality feel over 192 fine steps from 0 to 95.5dB.
Increased volume knob rotation speed and long-pressing of the volume buttons on the remote control moderately accelerate the increase or decrease of the output level.

Features

Electric circuit

  • Newly developed, high-quality sound with rich musicality, full of vitality, discrete amplification feedback engine LIFES adopted.
  • Fully balanced configuration with 4 preamplifier blocks achieves a completely direct circuit from balanced input to balanced output.
  • Combining our original LECUA electronically controlled attenuator with a heavy rotary mechanism realizes high-precision volume control over 192 steps of 0.5dB.
  • The gain of the preamp circuitry that handles a wide dynamic range has been increased to 15dB, where its predecessor, the C-900u, was 12dB.
  • Highly stable power supply combines a large-capacity CI core power transformer and custom-designed filter capacitors (3,300uF x 7).
  • For the internal wiring, we use original OFC cable that realizes natural signal transmission with special wrap shielding for each non-plated copper core wire.
  • 100μm thick, non-resistive, gold-plated peel coat circuit board tracing eliminates the dielectric effect of resistive
    coating for any audio circuit.

Function

  • LR balance adjustment, volume shift functions and bass/treble controls are handled by LECUA.
  • Input offset function can preset the input and output levels for multiple input devices over a range of 0 to -6dB for each stereo input.
  • Volume-linked loudness function matches human hearing characteristics (can be turned ON or OFF using the remote control).
  • Versatile output mode switching allows you to choose between unbalanced, balanced and bi-amped according to your listening system.
  • Bi-amp output mode levels for unbalanced connections may be set for each output (±6dB).
  • For balanced inputs 1 to 3, the phase preset setting (No.3 HOT<>No.2 HOT) is saved for each pair of terminals.
  • Equipped with an unbalanced external pre-input terminal that can be connected to the pre-output of an AV system or similar.

Design and exterior

  • Three-dimensional design common to the M-10X and D-10X, with large slanted sides and a bold contrast between the extra-thick front panel and chassis.
  • Fluorescent display with various modes, zoom and dimmer functions with excellent visibility that shines against fine blasted white finish. – Aluminum top panel with a fine hairline finish creates a contrast to the front panel.
    Mechanical features and accessories
  • Loop-less chassis structure eliminates the effect of rising ground impedance due to chassis currents and magnetic induction.
  • Cast iron legs protect the unit from unwanted vibrations due to their structural density gradient.
  • Original 27mm pitch, RCA terminals for unbalanced inputs and outputs, high-quality Neutrik XLR terminals for balanced inputs and outputs.
  • Control input/output terminals can sync remote control signals between compatible devices and expand support for remote operation by other wireless devices in the future.
  • Equipped with a new trigger input/output terminal that enables power syncing between compatible devices (daisy-chaining is also possible).
  • Dedicated RA-20 remote control made from high-quality aluminum with excellent operability.