Luxman’s “ODNF” circuitry feeds back only distortion components, achieving strong performance and a natural, non-feedback-like sound. Building on developments from the M-10X, the complex circuit has been fully redesigned to create the “LIFES” engine for next-generation components. The L-509Z uses independent LIFES modules in both fully discrete pre and power sections, supporting the “single-chassis separates” concept and delivering enhanced musicality and detail. Its output stage employs triple Darlington bipolar transistors in a quadruple-parallel push-pull configuration, producing 120 W + 120 W (8 ohms) and 220 W + 220 W (4 ohms), with high linearity and powerful sound.

A precise, tactile volume control is essential for amplifier performance, ensuring smooth attenuation while preserving input signal quality. Luxman’s LECUA system uses high-quality fixed resistors, independently switched per channel for accurate control. Since its introduction in 2006, LECUA has minimised vibration effects, maintained sound quality across the range, and resisted long-term deterioration. The L-509Z features the “LECUA-EX”, combining a rotary encoder with a weighted mechanism for improved reliability and feel. It offers 88 steps (0–87 dB), with adjustable speed and remote functions for smooth, high-quality control.

The L-509Z is equipped with Luxman's traditional, highly stable power supply circuitry, featuring a bespoke, highly regulated 600 VA EI transformer and newly developed large-capacity filter capacitors (10,000 μF × 8).

The built-in high-quality phono equalizer circuit, which supports both MM and MC cartridges, features a new two-step gain switch to select between high and low MC settings to accommodate a wider range of MC cartridges, enriching quality vinyl playback in terms of both operation and sound quality. And a Mute-Button is now featured on the front panel.

In addition to BASS and TREBLE, a new MIDDLE control effective in the vocal and lead instrument frequencies bandwidth has been included. LR balance, line straight, loudness, and other functions are also conveniently at your fingertips.

Peel-coat circuit boards are used for the main audio signal path, eliminating the negative effects of the coating film that can adversely affect sound quality. Unique attention has been paid to every detail, such as the beeline construction, which configures circuits to take the shortest route possible, and a non-angled wiring pattern for smooth signal transmission.

Large, low resistance speaker relays are connected in parallel to transmit the driving force from the substantial power supply and output circuitry. Internal, 3.5mm2 ultra-thick cable is directly connected to the speaker terminals to ensure low impedance transmission, achieving a damping factor of 330 (current injection method).

Needle-movement type analogue VU meters are a traditional design statement, proudly characterising LUXMAN’s solid-state integrated amplifiers. The L-509Z is equipped with two large meters, brightly back-lit by LEDs, with sensitive response characteristics. The newly included 7-segment LED display between the left and right level meters displays the current attenuation amount and is easily visible from the listening position.