RADAR is a price search engine. We link to the original listing — we never sell direct. Transactions happen on the source site.
Condition is unknown, so the US$1,200 ask lands a bit above your database median of US$1,050 and above the US$1,238 75th percentile would have to be cleared before I’d call it merely ambitious; as listed, this reads as upper-end fair rather than a bargain. For a clean, working example, that’s not a bad place to be, but I’d want the price to reflect verification and any service history since there’s no condition premium stated.
The M-504 has a solid reputation among vintage Onkyo muscle amps: substantial power, a straightforward stereo layout, and enough drive to make it a worthwhile keeper if it’s healthy. The upside is strongest if it’s original, well-maintained, and comes with proof of recent servicing or careful ownership; without that, the main buyer check is whether it runs quietly, stays stable under load, and has no channel imbalance or protection issues.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Onkyo traces its roots to postwar Japan, founded in 1946 in Osaka by Takeshi Goda, an engineer at Matsushita Electric who envisioned high-quality Japanese loudspeakers. Initially established as Osaka Denki Onkyo K.K., the company began production in 1948 with the acclaimed ED-100 speaker featuring a 25 cm driver, quickly building a reputation through LP concerts and innovative designs that resonated with audiophiles.
The brand excels in premium home audio, renowned for AV receivers, hi-fi amplifiers, and surround sound speakers that deliver exceptional clarity and power. Its portfolio spans turntables, DACs, headphones, and cables, bolstered by acquisitions like Pioneer's home electronics division in 2015, enabling cutting-edge integrations such as internet radio and high-resolution streaming.
Onkyo holds a solid mid-tier position in the hi-fi market, prized by discerning buyers for reliable performance and value rather than ultra-high-end exotica. Despite bankruptcy challenges in the late 2010s, its revival under new ownership preserves a legacy of technological innovation and pure sound enjoyment, appealing to both vintage enthusiasts and modern home cinema setups.
See all Onkyo listings on RADAR.
