LUXMAN L-507Z INTEGRATED AMPLIFIER

Overview

The LUXMAN L-507Z is a high-fidelity integrated amplifier designed to deliver exceptional audio performance. It represents the latest generation of LUXMAN's amplifier technology, incorporating advanced circuits and premium components for a rich and natural sound experience.

Key Features

• Newly developed original LUXMAN amplification feedback circuit LIFES, at the heart of the latest Z generation amplifier series.
• New LECUA1000 attenuator for precise volume control.
• Preamplifier outputs equipped with discrete buffer circuitry.
• Powerfully rich and energetic class AB amplification.
• New exteriors designed to make the system more attractive as a center unit.

Advanced LIFES Feedback Circuit

LIFES (Luxman Integrated Feedback Engine System) is a proprietary amplification feedback circuit that has been refined over 20 years, originating from the ODNF (Only Distortion Negative Feedback) system. First installed in a car audio amplifier in 1999, LIFES has undergone numerous revisions across five generations. The L-507Z is among the first amplifiers to feature this newly developed, high-quality LIFES circuitry, which aims to realize a fresh, natural tone by feeding back only the distorted component of the audio signal. The circuit and distortion detection system are integrated into a simple, compact unit, developed from scratch with careful selection of high-quality components.

The LIFES circuit utilizes N channel J-FET + PNP transistors for its voltage amplification stage, an evolution from the ODNF's P channel J-FET + NPN transistor configuration. This enhancement results in distortion being less than half and an improved S/N ratio by 3dB compared to the ODNF circuit.

LIFES Principle Diagram Description: A block diagram illustrating the signal path. It shows an input signal processed by a main amplifier with adjustable gain, a sub-amplifier, and a distortion detection circuit. The detected distortion is fed back through an attenuator (R1, R2) to the main amplifier's feedback loop, ultimately producing an output signal with reduced distortion.

L-507Z Power Block Description: A visual representation of the amplifier's power stage, showing a printed circuit board populated with numerous electronic components, including large capacitors and transistors, indicative of its robust power delivery system.

Precise LECUA1000 Attenuator

The LECUA1000 (Luxman Electric Controlled Ultimate Attenuator) is an advanced volume control system that evolved from LUXMAN's original LECUA system, first introduced in 2003. This system uses a microcomputer to control volume changes via relays, selecting resistors with varying resistance values. This method ensures precise attenuation with minimal left and right level deviation and no deterioration in sound quality. The LECUA1000 features a 3D layout board for direct connection between the attenuator and amplifier circuitry, offering balance adjustment from 0 to -6dB and 88 contact points for fine volume control from 0 to 87dB.

New LECUA1000 Board Description: A printed circuit board assembly featuring multiple relays and precision resistors, representing the core of the LECUA1000 volume control system.

Discrete Buffer Circuit

The output section of the preamplifier is equipped with a discrete buffer circuitry, similar to that found in the LUXMAN C-900u control amplifier. This design enhances the power amplifier's driving force while preserving the purity of the music signal, contributing to a sharp initial sound rise and an overwhelming sense of scale.

Discrete Buffer Circuit Description: A printed circuit board populated with numerous discrete transistors and other electronic components, forming the buffer stage that enhances signal integrity and driving power.

Design and Connectivity

The L-507Z features a phono equalizer with paralleled first-stage input FETs for superior analog playback quality. For headphone listening, it offers both the standard 6.3mm terminal and a new independent 4.4mm terminal (left and right), with ground wiring to improve L-R separation. Volume levels are clearly displayed on 7-segment LEDs situated between analog meters illuminated by white LED backlighting.

Connectivity is extensive, including external control input/output terminals for future expandability (supporting Wi-Fi and Bluetooth remote operations) and 3.5mm mono trigger input/output terminals for linking power supplies between compatible products (daisy-chaining). The amplifier is equipped with RCA input terminals for LINE-1, constructed from a copper alloy chosen for its conductivity and hardness.

The power supply is highly stable, combining a top-quality power transformer with large capacity filter capacitors (8 x 10,000μF). For vibration isolation, the unit rests on custom-made, large density gradient, cast iron feet.

Exterior and Rear Panel

The front panel of the L-507Z features an input selector with multiple line inputs (LINE-1, LINE-2, LINE-3, LINE-4, BAL LINE-1, BAL LINE-2), a separate input, MM/MC phono input, subsonic filter, standby mode, mono switch, loudness control, line straight mode, and speaker selectors (A, B, A+B). It also includes controls for bass, treble, balance, and volume, along with mute functionality and headphone outputs (PHONES-1, PHONES-2).

The rear panel provides comprehensive connections, including:

• Inputs: PHONO, LINE-1, LINE-2, LINE-3, LINE-4, BAL LINE-1, BAL LINE-2, MAIN IN.
• Outputs: PRE OUT, SPEAKERS A, SPEAKERS B, PHONES-1, PHONES-2, TRIGGER OUT, CONTROL OUT.
• Control/Trigger: TRIGGER IN, CONTROL IN.
• Ground: SIGNAL GROUND terminal.
• Power: AC IN socket.

Speaker load impedance specifications are provided: A+B: 8-16Ω, A or B: 4-16Ω. The unit is powered via AC IN and is made in Japan.

Block Diagram

The block diagram illustrates the internal signal flow and component relationships within the L-507Z. It shows how input signals from PHONO, LINE, and BALANCED LINE sources are routed through input selectors, RIAA equalization, LECUA attenuators, tone controls, and a pre-amplifier stage. This is followed by a buffer stage and then the main amplifier, which drives the speakers (A and B) and headphone outputs. The diagram also depicts the power supply system, including rectifiers and transformers, a protection circuit, and control interfaces like IR input/output and trigger connections.

Specifications

• Rated output: 110W+110W (8Ω), 210W+210W (4Ω)
• Input, separate in/output: LINE x 4, Phono x 1 (MM/MC), Balanced x 2, Separate in/output x 1
• Speaker output: A, B 2 line (A&B outputs are operable at the same time)
• Amplification circuit, Output configuration: LIFES1.0, Bi-polar triple-parallel push-pull
• Total harmonic distortion: 0.007% or lower (1kHz/8Ω), 0.03% or lower (20Hz~20kHz/8Ω)
• SN ratio: LINE: 105dB or more
• Frequency response: 20Hz~100kHz (+0, -3.0dB)
• Dimensions: 440(W)×178(H)×454(D)mm (including 20mm front knobs and 27mm rear terminals)
• Power consumption: 300W (operation), 86W (no signal), 0.4W (standby)
• Weight: 25.4kg (Main unit)
• Accessories: Remote control (RA-17A), Power cable