Luxman L-505V (1975)

Name: Luxman L-505V
Brand: Luxman

That first warm, weighty note from the L-505V hits like a memory you didn’t know you had—rich, full, and startlingly alive.

Overview

The Luxman L-505V isn’t just an integrated amplifier from 1975—it’s a statement. Released in October of that year as part of Luxman’s esteemed V Series, it carries the lineage of the SQ505 from 1968, now evolved into its fifth generation. Built with the precision and care that defined Japanese high-end audio at its peak, the L-505V was priced at ¥98,000 upon release, a serious investment for its time. This isn’t a minimalist amp for the casual listener; it’s a pre-main amplifier designed for those who demanded both power and refinement. With 55 watts per channel into 8 ohms and a distortion figure so low it borders on absurd—0.03% or less—it delivers performance that still holds up decades later. And while it’s solid-state through and through, owners often describe its sound as having a “tube-like flavor,” a warmth and body that transcends its transistorized core.

Specifications

Manufacturer	Luxman Corporation
Model	L-505V
Year Introduced	1975
Type	Integrated amplifier (pre-main amplifier)
Continuous Effective Output (8Ω)	55W + 55W
Continuous Effective Output (4Ω)	72W + 72W
Total Harmonic Distortion	0.03% or Less (8Ω, 55W)
Cross Modulation Distortion Factor	0.03% or Less (8Ω, 55W, 60Hz:7kHz=4:1)
Output Bandwidth	5 Hz to 50 kHz -3dB (0.1%)
Input Sensitivity / Impedance Phono1	2.5mV/30k ~ 50k ~ 100k Ω (continuously variable)
Input Sensitivity / Impedance Phono2	2.5mV/50k Ω
Input Sensitivity / Impedance Tuner, Aux1/2	150mV/50k Ω
Signal-to-Noise Ratio Phono1/2	62 dB or more
Signal-to-Noise Ratio Tuner, Aux1/2	80 dB or more
Maximum Allowable Input Phono	300 mV or more (RMS, 1 kHz)
Residual Noise	0.5 mV or less
Damping Factor	40 (8 Ω Load)
Tone Control	LUX System NF Type with Bending Point Frequency Switching
Low-range Bending Point	150 Hz, 300 Hz, 600 Hz, defeat
High-frequency Curved Point	1.5 kHz, 3 kHz, 6 kHz, Defeat
Low-cut	30 Hz (-6dB/oct.)
High Cut	8 kHz (-6dB/oct.)
Low Boost	70Hz (+6dB/oct)
Attachments	Input impedance adjustment for Phono1, Tape dubbing circuit, Attenuator (-18dB)
Semiconductor Used	Transistor: 47, IC: 1, Diode: 20 pcs, Zener diode: 4 pcs, Varistor: 4 pcs
Power Consumption	200W (8 Ω, both channel operation, at rated output)
External Dimensions	Width 450 x Height 160 x Depth 268 mm
Weight	11.5kg

Key Features

Pure Complementary OCL Design

At its heart, the L-505V uses a pure complimentary service OCL (Output Capacitor-Less) system, a design choice that eliminates output capacitors to preserve low-frequency response and transient accuracy. The entire amplifier chain—from input to output—is built around a two-stage differential-amplification setup fed by dual positive and negative power supplies. This architecture ensures balanced operation and minimizes distortion, contributing directly to its exceptionally clean 0.03% THD rating.

Emitter Follower Circuit for Class Isolation

One of the L-505V’s smarter engineering moves is the inclusion of an emitter follower circuit after the pre-driver stage. This does two things: it improves the high-frequency load condition of the pre-driver, and more importantly, it electrically isolates the class B pre-driver from the class A output stage. That isolation prevents the output stage’s impedance swings from affecting the pre-driver, a clever way to maintain stability and reduce distortion under real-world load conditions.

Class A Inverted Darlington Push-Pull in Preamp

The preamp section’s equalizer circuit combines carefully selected operational amplifier ICs with a high-voltage class A inverted Darlington push-pull output stage. This setup delivers low noise and high linearity, especially critical for the delicate phono signals it handles. The result is a phono stage that’s both quiet and dynamic, with a signal-to-noise ratio of 62 dB or more—respectable for its era.

Power Supply and Build Quality

Two massive 10,000 μF electrolytic capacitors anchor the power supply filter circuit, supported by a well-regulated transformer. This robust power delivery helps maintain stability even at full output. And then there are the 8 iron-case power transistors—built like tank turrets, they radiate durability and contribute to the amp’s 11.5kg heft.

Tone Control Flexibility

The L-505V doesn’t just amplify—it shapes. Its LUX System NF Type tone control offers selectable bending points: low frequencies can be adjusted at 150 Hz, 300 Hz, or 600 Hz, while highs pivot at 1.5 kHz, 3 kHz, or 6 kHz, with defeat options for purists. Add to that a low boost at 70Hz (+6dB/oct), a 30Hz low-cut, and an 8kHz high-cut, and you’ve got one of the most flexible tone systems of its time. Whether you’re taming a bright room or warming up a lean speaker, the L-505V gives you the tools.

Historical Context

The L-505V stands as the fifth generation in a line that began with the SQ505 in 1968, evolving into the V Series with a clear focus on refinement and performance. Luxman didn’t build this amp in isolation—they leveraged circuit technology developed for their high-end separates, specifically the M-6000 power amplifier and the C-1000 control amplifier. This cross-pollination of engineering know-how elevated the L-505V beyond typical integrated designs of the mid-70s, making it a serious contender in the high-fidelity landscape.

Collectibility & Value

Today, the L-505V is a sought-after piece among vintage audio enthusiasts, particularly in Europe where prices hover around €950 to €999 for functional units. Listings elsewhere vary—some as low as $132.50, others nearing $1,000—reflecting condition, location, and whether the unit has been serviced. A recap kit for capacitors can be had for around €24, but finding a full service manual is tough; owners often trade or seek them out on forums. Original user manuals still surface, with one recent example selling for $65 in Very Good condition. One known issue is the startup protective circuit relay, which can develop a progressively longer delay, accompanied by humming and mechanical noise, eventually failing to switch on. Recapping and relay maintenance are common restoration steps. Despite its age, the L-505V’s reputation for “tube-like sound” and its robust build keep it relevant in vintage circles.