Sansui AU-X1111MOS VINTAGE
Flagship integrated amplifier from Sansui's AU-X series, featuring twin monaural construction and a fully balanced, ground-free design
Overview
The Sansui AU-X1111MOS VINTAGE is the final model in the AU-X amplifier series, representing the culmination of Sansui's high-end analog design. It is a master integrated amplifier with fully independent preamp and power amp sections, capable of separation via front panel controls. Built around a balanced, ground-free "Earth-based" amplifier circuit, both speaker terminals are actively driven in a double push-pull configuration, supported by a closed-loop, ground-free power supply.
Specifications
| Year of Production | Not specified |
| Effective Output (8 Ω) | 110W + 110W (10 Hz – 20 kHz, both channels driven) |
| Dynamic Power (2 Ω) | 320W + 320W |
| Total Harmonic Distortion | 0.008% (10 Hz – 20 kHz, 8 Ω, rated output) |
| Damping Factor | 200 (8 Ω) |
| Frequency Response (Power Amp) | DC – 300 kHz (+0 dB, -3dB, 1W) |
| Slew Rate | ±150 V/μsec (8 Ω) |
| Signal-to-Noise Ratio (A-weighted) | 115 dB or more |
| Input Sensitivity / Impedance (Main In) | 1 V / 5k Ω |
| Phono MM Input Sensitivity / Impedance | 2.0 mV / 47k Ω |
| Line Input Sensitivity / Impedance | 150 mV / 47k Ω |
| Headphone Output | 400 mW (33 Ω) |
| Load Impedance | 4 – 16 Ω |
| Dimensions (W × H × D) | 470 × 178 × 486 mm |
| Weight | 35.1 kg |
| Rated Power Consumption | 350 W |
| Original Price | ¥400,000 (around 1988) |
Design
The amplifier uses twin monaural construction with a central heavy-duty power transformer and symmetrically separated amplifier sections mounted on dedicated heatsinks. The output stage employs 16 MOS FETs in a diamond differential configuration—four double push-pull pairs per channel—and features a DC-coupled signal path. Critical components including power MOS FETs, the transformer, and master volume control are mounted on a pure copper plate, with additional copper plating and copper insulators used throughout the chassis. The non-switching power supply uses a large transformer, custom high-capacity audio capacitors, and fast recovery diodes, with balanced transmission eliminating the need for a line filter. A dedicated video input with internal IC switching is powered by a separate transformer. The cabinet features real rosewood side and top panels, a front glass panel, and shower lights. The presence control boosts mid/low frequencies at low volumes without altering overall tone balance, and independent left/right channel volume controls are provided.
Context
The AU-X1111MOS VINTAGE is the final model in the Sansui AU-X series, which began with the AU-X1, marking the end of a high-fidelity amplifier lineage.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- Sansui 2000A (1968-1970)
- Sansui 3000A (1968-1970)
- Sansui 5000X (1969-1971)
- Sansui 551 (1973-1975)
- Sansui 6060 (1975-1977)
- Quad 44/405-COMBINATION (1976)
- Braun AUDIO-1 (1965)
- Braun AUDIO-250 (1965)
- Braun AUDIO-310 (1965)
- Magnavox Component Systems (1972)