RADAR is a price search engine. We link to the original listing — we never sell direct. Transactions happen on the source site.
At £100, this sits well below the £266 25th percentile and looks like a genuine bargain versus the recent used market, where the median is £329 and the upper quartile is £485. For a classic Quad power amp, that’s the kind of pricing that usually leaves room for a service and still keeps the overall outlay attractive.
The appeal here is straightforward: Quad’s 520 has the reputation for clean, stable, very listenable power rather than flashy specs, and it pairs well with revealing speakers when you want grip without glare. At this price, the main upside is value, but age matters more than cosmetics, so confirm it powers up properly, both channels behave evenly, and there’s no hint of hum or relay issues before jumping in.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Quad, the venerable British hi-fi brand, traces its origins to 1936 in London, when engineer Peter J. Walker founded S.P. Fidelity Sound Systems, soon renamed the Acoustical Manufacturing Company. Relocating to Huntingdon in 1941 after wartime bombing, the firm shifted from public address gear to domestic audio amid post-war demand for superior sound reproduction. Walker's pioneering ethos—prioritizing "the closest approach to the original sound"—defined Quad from its early QA12 amplifiers, adopted by the BBC, to the iconic Quad I of 1953.
The brand excels in amplifiers and electrostatic loudspeakers, revolutionizing both categories. The Quad II power amplifier of 1953 introduced cathode coupling for vanishingly low distortion, while the 1956 ESL 57 delivered the world's first full-range electrostatic speaker, employing a massless film diaphragm for unparalleled transparency and transient speed. Quad advanced into solid-state with the 1967 303 and transistor designs featuring innovative "Triples" output stages, later expanding to integrated amps like the 99 series, moving-coil speakers, and modern electrostatic models such as the ESL 988 and 989.
Today, under the International Audio Group since 1997, Quad holds a prestigious position in the high-end market, revered by audiophiles for its unyielding pursuit of accuracy over trends. Its heritage components command vintage collector status, yet contemporary offerings maintain a niche boutique appeal among discerning buyers seeking refined, distortion-free reproduction that honors Walker's legacy.
See all Quad listings on RADAR.
