Luxman L-410 (1982)

Little independent documentation survives for the L-410. No period review of it has surfaced in the archive. The manual's own German-language model listing points only to a test in Stereo Play (10/1983), and Luxman's own historical summaries tend to spotlight the L-550 series and the SQ-38 line instead. What the record does show is a well-equipped, mid-sized integrated from the company's Revolver series, released in October 1982 at ¥79,000 and built around Luxman's "Duo-Beta" circuit philosophy.

The factory literature spells out what Duo-Beta meant. First, a single-stage amplifier circuit that stays open-loop while keeping distortion low. Second, an appropriate amount of overall NFB combined with a DC servo that tightens control from the ultra-low band below the audible range. Third, a "plusX" power supply circuit isolated from the ground circuit to keep supply noise out of the signal. The same approach is applied to the equalizer section, which is given high gain to support moving-coil cartridges. The L-410 also carries Luxman's "phono straight" function. It is not a simple bypass. Luxman claims it separates the contact points and wiring of filters, balance controls and selectors out of the straight path.

Rated output is 75W + 75W into 8Ω (1 kHz, both channels). THD is quoted at 0.009% or less under the 8Ω, −3dB, 20 Hz - 20 kHz condition. Phono inputs cover both MM (2.5 mV/50kΩ) and MC (100 μV, high/low switching). Line, tuner, DAD and monitor inputs are 200 mV/40kΩ, and main-in is 200 mV/50kΩ. IHF-A signal-to-noise is quoted at 90 dB for MM, 67 dB for MC and 110 dB for the line-level inputs. There are two tape loops with dubbing in either direction, a 30 Hz subsonic filter, a 7 kHz high-cut filter, a low-boost of +8 dB at 70 Hz, and a turnover-shift tone control (±8 dB). Pre-out and main-in jacks let the preamp and power sections be split. The unit measures 453 × 135 × 425 mm, weighs 13.0 kg, and draws 180W.

On the workbench side, the service manual identifies the output stage as complementary pairs - 2SC3182/2SA1265, with 2SC2706/2SA1146 in the first lot. It gives a bias adjustment of 15 mV ±5 mV measured across the test points. Owners report it runs hot and that a well-maintained example can drive demanding loads. Condition is everything at this age, and capacitor replacement kits are sold for the model. Resale prices have been observed from roughly $62 up to $750 depending on condition, with recent European listings around €399. No consistent valuation exists.