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This is a notable piece: the M-506RS has a real cult following for its grip, drive, and understated build quality. At US$1,700, the asking price is clearly ambitious versus your recent comp set, sitting well above the US$1,100 75th percentile and far over the US$825 median, so I’d only call it a buy if this one is especially clean or unusually complete.
What keeps it interesting is that these older Onkyo muscle amps can still deliver a big, authoritative presentation with plenty of current on tap, which is exactly why collectors and listeners chase them. If it’s truly original, well serviced, and comes with documented maintenance or a pristine faceplate, that adds real upside; otherwise, at this level I’d want strong evidence the amp has been cared for, since age and service history matter more than the badge here.
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.
