An amplifier builder who went back to tubes.

Audio Research was founded in 1970 by William Zane “Bill” Johnson and began in Minneapolis, Minnesota, English Wikipedia says. Johnson told Robert Harley of Stereophile, in an interview first published in August 1994, that he built his first amplifier commercially in 1949, for a local audiophile who owned a Klipschorn loudspeaker, after coming back from Army service. In 1951 he started his own company, Electronic Industries, which built amplifiers one at a time and repaired televisions. He ran it until 1968, he said, when a local firm, Peploe, Inc., bought the business along with his patent applications and technical files and hired him as director of research. When that “didn’t work out,” he obtained his freedom in 1970 and started Audio Research “with the remnants of their folly.” English Wikipedia describes Electronic Industries as a specialty audio shop that ran until the mid-1960s; we follow Johnson’s own account and note the difference.

His choice of technology was the story. By 1970 transistors had displaced vacuum tubes in home audio. Johnson said that at a trade show in Washington, D.C., that year, where he showed the Dual 50 power amplifier and the SP-1 and SP-2 preamplifiers, an angry engineer told him: “You’ve set the audio industry back 20 years!” Johnson said he had tried transistors and disliked the sound, and he summed up his view in a line the company still quotes: “with an all-out design effort, vacuum tubes will win.” He designed solid-state products too, and the company says he believed in using the best device for each circuit, tube or transistor.

English Wikipedia calls Audio Research one of the oldest high-end audio makers still in operation and credits it with reintroducing the vacuum tube as the main amplifying device — though the article carries a notice that it reads like an advertisement, so we use it with care. The company says it grew “from a small operation in the back of Bill’s shop” into a self-contained factory. Johnson died on 10 December 2011 in Rancho Mirage, California, aged 85, Audiophile Review reported.

From Italian private equity back to private hands.

Audio Research stayed with its founder for 38 years. On 25 January 2008 it was acquired by the Italian private-equity firm Quadrivio SGR, which had bought the Vicenza loudspeaker maker Sonus Faber in 2007, Stereophile reported that month; Johnson became honorary chairman and stepped back from day-to-day running, with Terry Dorn as president. Quadrivio’s audio holding became Fine Sounds, which went on to add Sumiko in 2010, Wadia in 2011 and McIntosh Laboratory in 2012. English Wikipedia says Fine Sounds bought Audio Research; the report at the time names Quadrivio, so we give that. In May 2014 Quadrivio sold Fine Sounds in a management buyout led by its chief executive, Mauro Grange, and backed by LBO France and Yarpa, FinSMEs reported, and in August 2016 the group was renamed McIntosh Group, Twice reported.

In August 2020, in its 50th-anniversary year, McIntosh Group sold Audio Research to TWS Enterprises, LLC, a company wholly owned by Trent Suggs, its former North American sales manager, who returned as president; the sale was announced on 25 August, the trade site Strata-gee reported. Less than three years later the company was in trouble. In April 2023 it filed in Minnesota district court for an assignment for the benefit of creditors — a voluntary alternative to bankruptcy — with Lighthouse Management Group as assignee, Strata-gee reported. In June 2023 a judge approved the sale of its assets to AR Tube Audio Corporation, a private Delaware company with Valerio Cora, founder of the Toronto loudspeaker maker Acora Acoustics, as a director, CE Pro reported.

The leadership changed again in 2026. On 2 July 2026 Stereophile reported that Cora, a minority investor who had served for four years as the company’s executive leader, had been relieved of his responsibilities, and that Roger Hwang of Toronto, Audio Research’s major financial backer since 2023, had taken over as chief executive. A press release issued that day said Acora Acoustics and Audio Research “are separate businesses.” David Gordon, the company’s longtime brand ambassador, told the magazine that Audio Research is owned by three investors, including Hwang and Cora.

American hi-fi and its records.

American high-end audio grew into a movement in the 1960s and 1970s, with its own press: Stereophile, founded in 1962 by J. Gordon Holt, and The Absolute Sound, founded in 1973 by Harry Pearson, according to English Wikipedia.

The makers grew up far apart. In Minnesota, William Z. Johnson founded Audio Research in Minneapolis in 1970, and Jim Winey’s Magnepan loudspeaker dates from 1969. In Connecticut, Mark Levinson started his company in 1972, and Dan and Rondi D’Agostino founded Krell in 1980. In Kentucky, Thiel began in Lexington in 1976; and in California, Richard Vandersteen took his Model 2 to the 1977 Consumer Electronics Show.

Several later changed hands. The Mark Levinson name passed to Madrigal Audio Laboratories at a bankruptcy auction in 1985, and Harman acquired Madrigal in 1995, Harman says; Samsung bought Harman in 2017. Audio Research was bought in 2008 by the Italian investor Quadrivio, whose Fine Sounds group was later renamed McIntosh Group, and was sold on in 2020 and 2023. Thiel was sold to a Nashville investor in 2012 and stopped operating in 2018. Krell closed after Rondi D’Agostino’s death in 2024; its repair service restarted in 2025, trade reports say.

Today Audio Research is in Maple Grove and Magnepan in White Bear Lake, Minnesota; Mark Levinson is part of Harman, based in Stamford, Connecticut; Krell remains in Connecticut; conrad-johnson builds by hand in Virginia; and Vandersteen is in Hanford, California, according to their websites and English Wikipedia.

This guide sets out what can be checked about each brand — who founded it, who owns it, and what it says about where its products are made — and marks clearly what rests only on the company’s own word.

A Minnesota factory and a see-through meter.

Today Audio Research gives its headquarters as 6655 Wedgwood Road North, Maple Grove, Minnesota, a suburb of Minneapolis; it moved there from Plymouth in August 2018, English Wikipedia says. Its website says “manufacturing is done by hand in-house, from the ground up, in our Minnesota facility,” and a May 2025 press release said each new product is “meticulously handcrafted in Minnesota”; we give those as company claims. The detail is more nuanced than the slogan: reviewing the Reference 160M amplifiers in February 2019, SoundStage! Ultra reported that their case, meter, transformers, capacitors and circuit boards were designed in-house but manufactured off-site by North American suppliers.

The look has changed in recent years. SoundStage! reviews credit Livio Cucuzza, then chief design officer of McIntosh Group, with restyling the range from the GS series of 2014 onward, and with the GhostMeter, a see-through meter window through which the tubes stay visible. The company says adding transparency behind the meter was meant “to glorify the tubes in the background.” Its current range includes the Reference 330M monoblock amplifier, launched in May 2024, and the Reference 20 preamplifier — and, unusually for a name built on tubes, solid-state S-100 and S-200 amplifiers and an LS-3 preamplifier from what it calls a newly formed solid-state engineering team. Its 50th anniversary was marked by a company history written by Ken Kessler, Audio Research: Making the Music Glow.

For a design guide, Audio Research shows how a brand can keep one idea — the glowing tube — through a long string of owners. Compare McIntosh, its former stablemate, and Conrad-Johnson, the tube maker two economists started in 1977. For this guide we use silver, black and a warm tube amber with a sans, an unofficial interpretation; no product or logo is reproduced.

Keep Audio Research’s identity on hand — save it to a board in the Made Good inspiration library.