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For sale is a Audio Research D-51 tube amplifier in great condition. This was purchased from John at Van L Speakers in Norridge, IL. He went through it, biased it and tested tubes before sale and it has been used sparingly since purchase two years ago. It sounds incredible, burns hot and with the right speaker match produces a near perfect vintage tube sound. I unfortunately have too many speakers and amplifiers on hand and need to thin the heard.For local pick up only in the North suburbs of Chicago. This unit is just too heavy to ship.Specifications and DesignPower Output: 50 watts RMS per channel into 4, 8, or 16 ohms.Tube Complement: Four 12AX7, eight 6FQ7, and three 6550 power tubes.Frequency Response: 15 Hz to 30 kHz.Weight: 50 lbs (22.7 kg). [1, 2, 3]
This looks like a strong deal. At US$850, it lands well below the US$1,200 25th percentile and far under the US$1,890 median for recent comparable used listings, so the ask is genuinely attractive.
The appeal here is simple: Audio Research tube amps are prized for a big, supple, highly musical presentation with good tonal density and real listenability. If it’s operating properly and has healthy output tubes, this is the kind of buy that can deliver serious value; just confirm service history, tube health, and that it powers up quietly, since older tube gear rewards a careful check.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Audio Research Corporation, founded in 1970 in Minneapolis, Minnesota, by William Z. Johnson, traces its roots to his pioneering work in custom audio electronics during the 1950s and his operation of a specialty retail store through the mid-1960s. After a brief stint selling his designs to a larger firm, Johnson regained independence to establish ARC with a singular mission: advancing the state-of-the-art in music reproduction. From modest beginnings in the back of his shop, the company evolved into one of America's oldest continuously operating high-end audio manufacturers, now housed in a state-of-the-art 48,000-square-foot facility in Maple Grove, Minnesota.
ARC specializes in performance-driven electronics, renowned for vacuum-tube amplifiers, preamplifiers, and electronic crossovers that emphasize sonic purity over flashy features or aesthetics. Drawing on circuit designs rooted in the 1950s, the brand integrates tubes into modern contexts, delivering what it calls "high definition" sound through genuine technological advances. While not venturing into speakers, turntables, DACs, headphones, or cables, ARC's focused lineup prioritizes amplifiers and preamps that set benchmarks for musical realism.
Positioned at the pinnacle of high-end audio, Audio Research is hailed as a true originator of the genre, commanding respect among audiophiles for its unwavering commitment to excellence and innovation. Enduring the 1970s tube revival against solid-state dominance, ARC thrives via elite specialist retailers worldwide, standing alongside peers like Conrad-Johnson as a vintage-inspired yet forward-thinking force in the niche boutique market.
See all Audio Research listings on RADAR.
Paragon Sight & Sound
Dealer
Hifitörget
SE
eBay UK
GB
audio-markt.de
Good
audio-markt.de
Good
Marktplaats
↓ 12%
