RADAR is a price search engine. We link to the original listing — we never sell direct. Transactions happen on the source site.
The Onkyo Integra M-504 is a legendary vintage stereo power amplifier produced between 1987 and 1997. It delivers 165 watts per channel into 8 ohms and features a heavy-duty dual-mono construction to reduce crosstalk. Visually striking, it is famous for its massive, softly illuminated analog peak-power meters and real wood side panels. Audio enthusiasts praise the M-504 for its high dynamic power, exceptional clarity, and warm, effortless sound stage.SpecificationsPower output: 165 watts per channel into 8Ω (stereo)Frequency response: 1Hz to 100kHzTotal harmonic distortion: 0.003%Damping factor: 140Input sensitivity: 1VSignal to noise ratio: 120dBDimensions: 465 x 185 x 422mmWeight: 22.5kgLocal pick up / inspection / purchase available at Archer High Fidelity in Falls Church, VA. We are a vintage sales and service specialist covering the Washington DC metro area.All major credit cards accepted, as well as PayPal, check on clearing, and Venmo.Any other questions, please feel free to ask.
This is a fair buy at US$999, sitting just under the US$1,000 median and comfortably inside the recent US$928–US$1,225 middle band, so it does not need to be a steal to make sense. Given the age of this classic design, the listing matters more for condition and service history than for model novelty.
What makes it worthwhile is the M-504’s reputation as a muscular, no-nonsense stereo amp with plenty of headroom and a loyal following among vintage Onkyo fans. If it’s clean, original, and working properly, this is the kind of piece that can anchor a system nicely; at this price, I’d mainly want proof of stable operation, quiet channels, and any recent servicing.
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.
