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Read through for shipping info. We ship internationally by a courier at heavily reduced rates.See store for more cool finds.Scroll down for video.I'll have the one from the top shelf, if you please...Here is a 1973 Harman/Kardon 50+ Quadraphonic/Stereo Receiver. It's an absolute gem. Green light with VU meter under black glass. 50 watts (12.5 watts × 4 channels @ 80hms). Usable in stereo or quad. Crystal clear sound. It's 23lbs of vintage hi-fi goodness. This unit has not been recapped or restored and is in original condition with a two-pronged power cord. Tested and working as it should.• Clean black-glass dial• Bright green LED dial illumination• Brushed aluminum faceplate• Strong, readable lettering• Knobs and pushbuttons are present andclean• Tuning meter illuminates• Rear panel is readable• Interior appears clean and orderly• Normal age-appropriate wear consistent with a vintage receiver• Model: Harman/Kardon 50+ • Serial No.: 24961579 • Made in Japan • AC: 117V. 60Hz • Power consumption: 140W . AC fuse: 2A / 250V • DC fuses: Right / Left 1.5A / 3AG • Switched AC outlet: 200W max • Inputs include Phono • Discrete Phono / Aux Front / Back • Tape Monitor Front / Back • Tape Out Front / Back • Front and Back speaker outputs • FM 300Q antenna connection • AM antenna connectior • Ground terminal • Quad / multichannel switchingNumber of TransistorsSemiconductors present.SemiconductorsMain Principle: Superheterodyne (common)Wave Bands: Broadcast (BC) and FM or UHF.Details: Radio with phono and aux.Power type and voltage: Alternating Current supply (AC) / 110 VoltLoudspeaker: This model requires external speakers.Power Out: 50 W (unknown quality)Material: Metal & Brushed Steelfrom Radiomuseum.org:Model: Multichannel Receiver Model 50+ - Harman Kardon; New YorkShapeBook-shelf unit.Dimensions (WHD)420 x 155 x 350 mm / 16.5 x 6.1 x 13.8 inchHarman Kardon Multichannel Receiver Model 50+AM/FM Stereo 4-Kanal Receiver mit SQ-Matrix.Continuous Power (Stereo): 25 watts, RMS, per channel into 8 ohms at 1 kHz.Continuous Power (Quad): 4 x 12.5 watts, RMS, per channel into 8 ohms at 1 kHz.Total Harmonic Distortion: 0.3% at l kHz.Intermodulation Distortion: 0.5% (40 & 4,000 Hz) 3dB down in power.Frequency Response: 18-74,000 Hz ±1.0dB.Power Bandwidth: 28-30,000 Hz, 3dB down.Matrix Phase Differential: 0° to ± 6°.Matrix Overload: 4 volts, RMS, 20-20 kHz.Matrix Frequency Response: 20-20 kHz (uniform amplitude).FM Sensitivity: 2.8 microvolts, IHF.FM Total Harmonic Distortion: 0.9%.Ultimate Signal to Noise: 62dB.Capture Ratio: 3.0dB.IF Rejection: 60dB.Spurious Response Rejection: 60dB.Stereo Separation: 30dB.AM Sensitivity: 30 microvolts.Image Rejection: 40dB.Made in JapanNet weight (2.2 lb = 1 kg)11.5 kg / 25 lb 5.3 oz (25.33 lb)Overseas buyers contact us with your address for an accurate shipping quote.Items are packed properly and shipped within twenty four hours.
Condition is unknown, so the price has to carry most of the signal here, and at US$567 it lands well above the US$325 75th percentile and far from the US$173 median. That makes it an ambitious ask rather than a fair-market buy, unless the unit has truly exceptional provenance, cosmetic originality, or a fresh service history that the listing clearly documents.
That said, this era of Harman Kardon quad/stereo receivers has real collector appeal: substantial build quality, period-correct styling, and a format niche that tends to attract enthusiasts rather than casual buyers. If it’s complete, original, and fully functioning, it could still make sense for a serious collector—but at this level I’d want proof of service, clean controls, and no missing knobs or switches before paying up.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Harman Kardon traces its origins to 1953, when Dr. Sidney Harman and Bernard Kardon, both engineers frustrated with conservative audio manufacturing at the David Bogen Company, invested $5,000 each to launch their venture in Westbury, New York. Their debut product, the Festival D1000, became the world's first compact AM/FM hi-fi receiver, blending breakthrough technology with sleek design to make high-fidelity sound accessible beyond technical enthusiasts. Pioneering innovations like the 1958 Festival TA230 stereo receiver, the 1959 Citation II ultra-wide bandwidth tube amplifier, and the 1970 CAD5 hi-fi cassette recorder with Dolby noise reduction cemented their legacy in simplifying premium audio for the home.
The brand focuses on integrated receivers, amplifiers, tuners, and speakers that emphasize performance, reliability, and elegant industrial design. Over decades, it expanded into home theater systems and automotive audio, powering systems in vehicles from Land Rover and BMW to Volvo and Polestar. While not delving into turntables, DACs, headphones, or cables, Harman Kardon prioritizes cohesive hi-fi components that deliver warm, detailed sound without unnecessary complexity.
Harman Kardon holds a solid mid-tier position in the hi-fi market, renowned among knowledgeable buyers for its enduring quality and value rather than ultra-high-end exotica or vintage collector status. Now part of Harman International, it appeals to discerning listeners seeking dependable, stylish gear that echoes its innovative heritage without commanding boutique premiums.
See all Harman Kardon listings on RADAR.
