Sansui's late-1970s integrated amplifiers are a favorite of vintage buyers who want a strong amplifier with a good built-in phono stage and no tuner. The x17 series was introduced around 1977 and was sold through the end of the decade. The AU-919, from about 1978, sits above it with a different circuit design. This guide covers the four models in our catalog: the AU-217, AU-517, AU-717 and AU-919.
What the x17 series is
The "17" in the model number marks a generation, not a power class. Higher numbers mean more power and features. Sansui marketed several of these amplifiers on DC-coupled ("DC") power amplifier designs intended to extend bass response and remove coupling capacitors from the power amp path. All four amplifiers here have a built-in phono stage for moving-magnet cartridges. The AU-919 adds a moving-coil input.
The models
AU-217: 30 W per channel
The AU-217 is the entry model in our catalog, rated at 30 W per channel into 8 Ω. It gives you the Sansui look and phono stage in a smaller, lighter box. It suits efficient speakers in a small or medium room, or a desk system.
AU-517: 65 W per channel
The AU-517 (c. 1977–1979) is sold as an "Integrated DC Stereo Amplifier" and is rated at 65 W per channel into 8 Ω. It is the middle ground: more than double the AU-217's power, but cheaper and lighter than the AU-717, and enough for most bookshelf and floor-standing speakers of the period.
AU-717: 85 W per channel
The AU-717 (c. 1977–1979) is rated at 85 W per channel into 8 Ω (125 W into 4 Ω) and weighs about 39 lb (17.8 kg). Its build explains the reputation. It has two separate power transformers, one per channel, which is unusual for a mid-priced integrated, and a moving-magnet phono stage housed in its own shielded enclosure. The bass and treble controls have switchable turnover frequencies and can be defeated, and there are pre-out and main-in jacks, two phono inputs and a subsonic filter. If you want one amplifier that can drive most speakers and play records well, this is the one most buyers aim for.
AU-919: 110 W per channel
The AU-919 (c. 1978–1981) is rated at 110 W per channel into 8 Ω in Sansui’s US literature (European spec sheets list 100 W). It uses Sansui's "Diamond Differential DC" circuit in the power amp and phono equalizer and offers both moving-magnet and moving-coil phono inputs. Its power supply uses several separate supplies, including a toroidal transformer and large oval filter capacitors. It is the most sophisticated amplifier here and also the hardest to service: technicians who work on it describe more than a dozen trimmer adjustments, including several in the MC stage, plus servo circuits that control DC offset.
Which one to buy
- Small room, efficient speakers: AU-217.
- Most people, most speakers: AU-517 or AU-717. The AU-717 is worth the extra weight if you value the dual-transformer build and phono stage.
- You run a moving-coil cartridge or want the top model: AU-919, ideally one that has already been properly serviced.
If you want a tuner in the same box, Sansui's receivers in our catalog, the G-7700 and G-9000 plus the older 5000A and 7070, are a separate shopping decision with their own model pages.
What fails on these amplifiers
- Corrosive adhesive. Sansui used a glue on its circuit boards that becomes corrosive with age. Restorers report it attacking component leads badly enough that parts can break off. A proper service removes it, and it is one reason "serviced" should mean more than a quick clean.
- Protection relay. The speaker relay's contacts oxidize, causing a channel that cuts in and out or stays silent. The relay can be cleaned or replaced.
- Noisy controls and switches. Volume, balance, tone, and selector controls crackle. Cleaning needs care, because the wrong contact cleaner can leave residue.
- DC offset and idle current. Direct-coupled amplifiers need correct DC offset and output-stage bias. On the AU-919 the servo circuits also have to be working. These are adjusted to the service manual, not by ear.
- Aging capacitors. Expect some capacitors to have drifted. Good technicians test before replacing rather than swapping every part on the board.
How to read an eBay listing
- Ask for a video of the amp playing a record through both speakers, with the volume swept up and down and each input selected. Crackle or a dropping channel points to dirty controls or the relay.
- Ask how long the relay takes to click in after power-on and whether it ever drops out during play.
- "Serviced" needs specifics. Ask whether the board glue was removed, which capacitors and relay were replaced or cleaned, and whether DC offset and idle current were set to the service manual. The restoration guide covers what to ask.
- "As-is" or "untested" on an AU-919 means a specialist service job, not a weekend clean.
- Packing matters. The AU-717 weighs about 39 lb. Ask for double-boxing with solid foam. Heavy transformers can break loose or crack the chassis when a box is dropped.
- Check the rear panel for missing phono ground posts, damaged RCA jacks, or a replaced power cord.
For current asking prices, see the live eBay snapshot on each model page.
