Harman Kardon PM650 (1982)

Name: Harman Kardon PM650
Brand: Harman Kardon

The Harman Kardon PM650 is a stereo integrated amplifier made in 1982. Period sources call it a "successful and popular" model. It put out 60 watts RMS per channel into 8 ohms (20 Hz-20 kHz, both channels driven), with total harmonic distortion rated at no more than 0.09%. Damping factor was specified at 80. It sat in a family with the PM640 (a version without tone controls) and the PM660 (a higher-powered model).

Two companion modules were offered with the PM650. The HT650 was a plug-in speaker switcher with A/B switching circuitry. The HMC650 was an audio control console that added a signal processor loop, two tape deck connections, and extra inputs. The PM650 measures 440 × 121 × 260 mm (W×H×D). No weight figure survives in the record.

One point of contention: frequency response figures vary by source. One database lists 10 Hz–200 kHz (+0, −3 dB), while another claims 5 Hz–250 kHz. Given the conflict and no authoritative manufacturer document to settle it, the exact figure remains unresolved. The signal-to-noise ratio is documented as 80 dB on the phone input — likely meaning "phono," though the sources state it as written.

Owner commentary from 2005 forums compares the PM650 with other amps. One listener set it against a Yamaha A-1020 and a Sony STR-VX500 and asserted "The Harman Kardon PM650 will definitely sound the best of the three," while conceding the Yamaha had notably more power. Another owner reported pairing the PM650 with Klipsch Forte II speakers. No original retail price, weight, or common-failure information has been found.

Audio (October 1982, p.37) ran a brief amplifier section item that appears to reference the PM650. The OCR quality of that period listing is too degraded to extract specific claims.