Kenwood KA-880SD (c. 1975–1978)

The Kenwood KA-880SD is a stereo integrated amplifier from the mid-1970s, built by Trio Electronics. It was one of the top models in Kenwood's range at the time. It belongs to the "S" series, known for its "Super-Duo" design - dual power supplies and dual FET differential input stages. The circuit is direct-coupled throughout, with a DC power amplifier stage and relay protection on the outputs. A large toroidal transformer feeds the dual supplies.

Rated output is 75 watts per channel into 8 ohms and 100 watts into 4 ohms. One source lists 80W RMS at 8Ω, but the 75W figure appears more consistently. Frequency response is specified at 20Hz-20kHz ±0.5dB, with THD of 0.05% and a signal-to-noise ratio of 110dB. The phono stage accepts 2.5mV/47kΩ, and line inputs are rated at 150mV/50kΩ. It weighs 9.8kg and measures 430 × 122 × 266mm. Features include tone controls with a defeat switch, loudness, two speaker outputs, and a tape monitor loop.

Audio (October 1985, p.164) listed the KA-880SD among amplifiers in a period roundup, though detailed test measurements from that review do not survive in the record.

Collector reception is generally strong, though descriptions of the sound differ. Some call it warm, others lively and detailed. It's regarded as a well-built, high-power unit from the era when Kenwood was competing hard with other Japanese manufacturers. Typical asking prices today run from roughly €350 to €600, depending on condition.

There are two caveats for buyers. The protection relay is known to fail, and the electrolytic capacitors, especially in the power supply, are well past their designed lifespan. Plan on a recap at minimum. Kenwood no longer stocks parts, so used components are the only source for most repairs.