Audio Research

Browse Audio Research vintage audio equipment in the Vintage Technology Archive.

Amplifiers

• D-79 — A high-powered tube amplifier built in the USA with a regulated power supply and forced-air cooling for sustained high-fidelity performance.
• D79B — A rare tube power amplifier using a quad of 6550 or KT88 output tubes, originally priced at $3000. Includes the complete spec table and when it was made.
• S-100 — Audio Research S-100 solid-state amp: 100WPC, dual-mono, fully balanced. Minnesota-built, $9,450. Serious engineering, no tubes.

Cd Players

• CDT-1 — Audio Research CDT-1 CD transport from the mid-1990s. Period reviews note AES/EBU, BNC, and ST outputs; $649 price for Reference One version.

Power Amplifier

• D-100 — Obscure Audio Research D-100 known only from 1977-1981 classified ads; no manual, specs, or reviews documented.
• D-1008 — Audio Research D-1008 is an obscure model documented only by a 1980 Audio magazine classified ad offering one for $1,700; its component type is unconfirmed.
• D-100B — Audio Research D-100B — an obscure model known only from a 1981 classified ad in Audio magazine. No specs or documentation survive.
• D-110 — Little is documented about the Audio Research D-110 amplifier. Classified ads in Audio magazine (1979–1980) list it from $1,850 down to $1,250.
• D-350 — Audio Research D-350 amplifier — known mainly from period classified ads (1978–1981); otherwise little documented. Covers when it was made.

Power Amplifiers

• D-1004 — Audio Research D-1004, circa 1979 — almost entirely undocumented. Only known from classified ads in Audio magazine at $895. No specs or design details found.
• D-110B — Audio Research D-110B — an obscure amplifier documented only by 1980 classified ads in Audio magazine; no specs or production details confirmed.
• D-240 — Little is documented about the Audio Research D-240, but the period record establishes the essentials: it was a solid-state stereo power amplifier
• D-250 — Audio Research D-250 Mark II Servo vacuum-tube power amplifier (circa 1986): $6,900, about 240 W/ch, reviewed in Audio magazine. Little else documented.
• D-300 — Audio Research D-300 stereo amplifier. Little documented; known from Audio magazine (Jan. 1995) as a solid-state amp priced at $3,995 with a fast.
• D-52B — Audio Research D-52B, circa 1979, is documented only by a December 1979 classified ad in Audio magazine listing it at $850; no specs or reviews survive.
• D-75A — Little is documented about the Audio Research D-75A. No specs, reviews, or ads for this model have been found; even its component type is unconfirmed.
• D-76A — Little is documented about the Audio Research D-76A. No owner's manual, catalog sheet, or dedicated review has surfaced, but the period classifieds leave.
• M-300 — Audio Research M-300 (c. 1986–1988): 300W amplifier rated into 8 ohms; reviewed in Audio's AURICLE column Nov 1988. A thinly documented ARC model.
• VT-50 — Audio Research VT-50 tube amp, 45W/ch, late 1990s VT series. Documentation is thin; known from Audio magazine reviews.

Preamplifiers

• D-1 — Audio Research D-1 phono preamplifier. Solid-state, 47kΩ input, 65dB MC gain, 70dB S/N. Warm liquid sound. Little factory documentation.
• EC-4 — Audio Research EC-4 electronic crossover from the mid-1970s. Little is documented; known only from classified ads in Audio magazine (1975–1979).
• EC-4A — Audio Research EC-4A electronic crossover from the mid-1970s. Little documented—known only from a $275 classified listing in Audio (1977).
• LS-3 — Audio Research LS-3 (1992) solid-state preamp: 5kg, 480mm, 20dB gain, touchscreen, optional DAC/phono cards. A rare transistor departure from a tube legend.
• PH-1 — Audio Research PH-1 tube phono preamplifier (1990–1994). Part of the Linear Reference series. Fully balanced dual-mono design.
• SP-10 — Audio Research SP-10 (1982) — dual-chassis tube preamp with 6DJ8 tubes, 5Hz–30kHz response, and legendary phono stage. Covers detailed specs.
• SP-12 — Obscure Audio Research SP-12 preamplifier; only a fragmentary 1986 HiFI-Stereo directory listing survives, with specs unconfirmed.
• SP-3 (1972) — Audio Research SP-3 (1972) tube preamp: 9.7kg, 15Hz–30kHz response, 8 inputs. A landmark that proved tubes could rival solid state.
• SP-6C — Little is documented about the Audio Research SP-6C. What the record shows: the model appeared in a classified advertisement in Audio (January 1983, p.87)

Unknown

• 350B — Obscure Audio Research 350B: only surviving record is a 1980 High Fidelity spec sheet — 45W into 8 ohms, phono/tape/tuner/aux inputs.
• 76-A — Audio Research 76-A (D-76A): obscure tube amplifier known from late-1970s Audio classifieds at $750.
• 90A — Audio Research 90A — a little-documented model from the American tube specialist. No specs or production dates are in the archive record.

Other Models

• D 51 — Audio Research D51 solid-state stereo amplifier from the mid-1970s, 50W/ch, $750 original price. Little-documented model with conflicting production dates.
• D 70 — Audio Research D70 (1972-1979), the company's first solid-state power amplifier. 70W/ch, $1,200 new. Designed by William Z. Johnson.
• D 75 — Audio Research D 75 (1975) tube stereo power amplifier. 75W/ch, 4x6CA7 outputs, $495 at launch. Single-source documentation from The Absolute Sound review.
• D 76 — Audio Research D76 (1971–1976) — the 60W tube power amp that established ARC as a serious high-end manufacturer. First ARC amp to use 6550 output tubes.
• D 80 — Documentation on the Audio Research D 80 is thin — the record consists of a single equipment listing, with no production years or original price that I've.
• DUAL-150 — Audio Research DUAL-150 — a $1,995, 300-watt tube power amplifier from the mid-1970s, flagship of the ARC line and reviewed by Absolute Sound.
• DUAL-76 — Audio Research DUAL-76 tube amplifier — a dealer-supported system anchor of the mid-1970s, sold alongside SP-3 preamps and Tympani speakers. Specs undocumented; collectibility real.
• EQ 2 — Audio Research EQ 2 stereo graphic equalizer, 30 bands per channel, ISO 1/3-octave spacing, solid state, $1,795 original price. Little-documented model.
• LS 2 — Audio Research LS 2 line-stage preamplifier, introduced 1990. All-tube transformer-coupled design with 3x 6922 tubes, 12dB gain, five line-level inputs.
• LS28 — Audio Research LS28 (2016) tube preamp: 15.9 lb, 115dB SNR, 6H30 tubes. A Foundation Series standout with Reference 6 DNA.
• LS2B — Audio Research LS2B preamp (1992) — 6.0kg hybrid tube/solid-state line stage with balanced XLR, 1Hz–100kHz response. A cult favorite among vintage audiophiles.
• S 200 — Audio Research S 200 stereo power amplifier delivers 200 WPC into 8 ohms with dual-mono Class AB design and custom heat sinks — a modern high-end solid-state statement.
• SP-11 — A two-box hybrid preamplifier marking the midpoint of Audio Research’s shift toward neutral, transparent sound. Covers when it was made.
• SP-3A1 — Little is documented about the Audio Research SP-3A1 preamp. Known from period Audio listings: a 1975 appearance and a $500 used price in 1977.
• SP8 — Audio Research SP8 (1981) tube preamplifier: 22 lbs, 8 tubes, 20Hz-20kHz response. A transparent, service-intensive classic still revered for its honesty and depth.