Luxman L230 (Late 1980s)

An integrated amplifier from Luxman’s L200 series, known for its Duo-Beta feedback and solid-state power output stage.

Overview

The Luxman L230 is an integrated amplifier from the late 1980s, part of the L200 series. Luxman (Alpine) built it with a phono stage for MC and MM cartridges and a fully symmetric bipolar transistor output stage. It was aimed at high-quality sound at an accessible price. Two things set it apart: the tone controls sit inside the power amp's feedback loop, and it uses Duo-Beta feedback. It follows a single PCB construction policy, with the power transistors soldered directly to the main board.

Specifications

Power output	30 watts per channel into 8Ω (stereo)
Frequency response	20Hz to 20kHz
Total harmonic distortion	0.05%
Input sensitivity	2.5mV (MM), 150mV (line)
Signal to noise ratio	70dB (MM), 90dB (line)
Output	4V (Pre out)
Speaker load impedance	4Ω to 16Ω
Semiconductors	2 x IC, 26 x transistors, 16 x diodes
Technology/Features	incorporates Duo-Beta feedback
Technology/Features	tone control is in the feedback line of the power amp; no traditional tone amp
Construction	single pcb policy; power transistors directly soldered to main pcb
Phono stage	common IC grade MC & MM/MD pick-up amp
Protection	The protection circuits are rather simple
Output stage	fully symmetric and complementary bipolar transistor power output with high speed & high current plastic power transistors
Power supply capacitors	C134, C135 of 10000 uF
Dimensions (W x H x D)	438 x 140 x 320mm
Weight	9.0kg

Design

The L230 uses one PCB, with the power transistors soldered straight to the board. That simplifies construction but may contribute to thermal stress. The tone control sits in the feedback line of the power amplifier instead of in a conventional preamp stage. The amp has Duo-Beta feedback and a fully symmetric bipolar output stage built on high-speed, high-current plastic power transistors. The power transformer is larger than the one in the L200 model, and most L200 series amplifiers share the same power rail voltages.

Context

The L230 was sold as an affordable, high-quality amplifier in Luxman’s L200 series, which gained a reputation for outstanding sound quality and build. The components became legendary among audiophiles for their excellent audio performance. Some models in the series lack an MC/MM switch and have only one front panel lamp. The page doesn't specify whether the L230 has these traits.

Market

Common problems include a vulnerable muting circuit, wrong capacitor ratings (such as 35V caps on a 46V rail), and possible PCB damage from a flawed original power design. Some units were badly repaired with BD249/BD250 transistors instead of the original 2SA1263/2SC3181. Recommended maintenance is replacing numerous capacitors, particularly C118 at the power-amp input. Modifications include swapping the front panel lamps for LEDs, separating the power supply rails per channel, and bypassing the front panel speaker switches. Sanken 2SA1694 and 2SC4467 replacement transistors have been used successfully.