Pioneer A-339 (1990–1991)

The A-339 is a stereo integrated amplifier from Pioneer's early-Nineties lineup. It was built in Japan and rated at 40 watts per channel into 8 ohms. The dating is approximate - the record points to roughly 1990-1991 - and it sits in a family of closely related models. Its predecessor was the A-337 and its successor the A-401, and it's often described as the "younger brother" of the A-777. The A-449 and A-339-S were stablemates, the latter being the same amplifier in a different color.

The service manual covers the A-339 alongside the A-449. It firms up the power figure: 40 watts per channel minimum into 8 ohms across 20 Hz - 20 kHz, with total harmonic distortion no higher than 0.02%. The same manual also quotes a 60 W / 0.009% figure for other types in the series. Don't apply that number to the A-339. The amp has six inputs, including a phono stage, with adjustable bass and treble and a tone bypass for a cleaner signal path. It also has a facility for adding a graphic equalizer. It measures 420 × 352 × 126 mm, weighs 6.9 kg, and was sold in both black and silver finishes. The manual lists a range of destination variants (KU, HE, HEWZ, SD, KC) with differing mains voltages and switched AC outlets.

Owner impressions are sparse but positive. One long-term user on the HiFi Database rated it four out of five with the verdict "Great amp. Never failed," and recalled it driving a pair of Quadral Odin speakers to good effect before being retired for Quad electrostatics. Beyond that, the record is thin. There is no confirmed original retail price, no service-bulletin history, and no detailed failure data beyond that owner's clean bill of health.

Known specs: