Sansui Electric · AU-series integrated amplifiers

AU-9900

One of the two 1975 AU flagships (with the AU-11000), 80 W/ch and the first Sansui with a DC power unit stage.

Catalogue code: AU-9900
Years: 1975
Type: integrated amplifier
Valves & speakers: 80 W + 80 W into 4 or 8 ohms
Lifecycle: retired
Confidence: High

Specifications

Watts: 80
Watts_basis: per channel, 8 ohm load unless noted in rated_load
Channels: 2
Technology: solid-state
Class_of_operation: not stated in the catalogue sheet
Weight: 17.9 kg

Safety

Mains-powered vintage Sansui: the AU-X1 and BA-5000 run high rail voltages and are unstable if the original capacitors have dried out. The 'Blackface' and 'Definition' faceplates are easily scratched; the wood cabinets are usually missing.

01 / Witnesses

What applies here

Marks that can be entered for this maker: Serial number, Model / catalogue number, British capacitor code (Hunts, Mullard), Japanese capacitor code (Nichicon, Chemi-Con, ELNA), EIA component code, Chassis / platter stamp, Version & era marker.

02 / Bounds

The model year is a floor

Nothing predates 1975; components only push the date later.

03 / Value

What moves the price

Sold-listing reading: fair JPY 31,000, good JPY 49,508, excellent JPY 88,800 JPY · 5 sold listings · as of 2026-10-18. 5 completed sales in JPY observed on 2026-10-18. fair/good/excellent = min/median/max of the observed SOLD prices (31000 / 49508 / 88800), NOT condition grades - neither source publishes a per-condition split. Sale/completion dates span 2026-03-02 to 2026-10-06. Channels counted: yahoo_closed x3, mercari_sold x2. No exchange-rate conversion was applied anywhere in this file.