Luxman SQ5B (1962)
The Luxman SQ5B is a tube-type pre-main (integrated) amplifier released in August 1962 at ¥35,100. It was announced as an improved version of the earlier SQ5A. It's compact but heavy: 390mm wide, 155mm high, 290mm deep, and 11.2kg. The tube complement is 12AX7×3, 6AN8×2, 6BQ5×4, and a 5AR4 rectifier. Output is rated at 14W+14W into 4, 8, 16, or 32Ω loads, with distortion of 1% or less at full output and 18dB of negative feedback in the main amplifier.
The SQ5B is built a little differently, and a lot of the effort went into hum reduction. The preamplifier section runs on a DC ignition system. The cabinet uses Art Bond, a vinyl-and-metal laminate developed by US Rubber Co., chosen for its printability and high electrical insulation. That design earned the SQ5B a good-design nod from Osaka Design House. The front panel carries a unique "Conometer" output meter, which puts two independent metering mechanisms in a single display so you can watch both channels' balance and level changes at a glance. A click-stopped tone control position lets you set flat response precisely. The tone control itself is a new NF-type circuit, claimed to reduce distortion versus conventional designs. A seller's note adds that the driver valves are clearly marked 6AN8 on the chassis, matching the documented complement.
Input sensitivity is high: 3.5mV for tape and 4.5mV for magnetic phono, with 250mV for tuner and crystal inputs. Signal-to-noise runs 54dB (tape), 60dB (MAG), and 65dB or better (tuner/X'tal) at maximum volume with tone flat. Power draw is 115W from 90-110 VAC.
The record on the SQ5B is thin beyond these specs. There's no documented frequency response figure, no production run length, and no independent period review that has turned up. What survives is mostly in the hands of collectors. One Russian forum post describes a unit visibly restored with quality capacitors (Nichicon, Unicon, Marcon, Elna, Shizuki). Another Russian listing, priced at 69,000₽, describes the sound as "velvety timbre, warm and comfortable." An eBay listing from 2026 shows one offered at £668.
- Output: 14W + 14W
- Output impedance: 4, 8, 16, 32 Ω
- Tubes: 12AX7×3, 6AN8×2, 6BQ5×4, 5AR4×1
- Dimensions: 390 × 155 × 290 mm; 11.2 kg
- Price at release: ¥35,100 (August 1962)
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- Luxman MS-11 (1974)
- Luxman 5L15
- Luxman 5T-50 (1977)
- Luxman C-03 (1978)
- Luxman C-9II (1979)
- Eico 3150 (1967)
- Fisher CUSTOM-ELECTRA-I (K-14/K-15) (1957)
- Fisher CUSTOM-ELECTRA IV (E33/E44) (1960)
- Akai AM-2400 (1978)
- Akai AM-2600 (1977)