A studio basement on West 54th Street.

Eventide began in Manhattan. The company’s own history names three co-founders: the recording engineer Stephen Katz, the inventor Richard Factor and Orville Greene, the owner of a small studio. English Wikipedia names the studio as the Sound Exchange, on West 54th Street, and describes Greene as a businessman and patent attorney. The company dates itself to 1971 — “since 1971,” as its press releases put it — although its history says the “improbable” name was settled in 1970. English Wikipedia adds that the firm was earlier known as Eventide Clock Works Inc.

The first product was not an effect. Because the studio had no room for a tape operator, the company says, Katz asked Factor to build a gadget that would return the tape on its Ampex MM1000 multitrack recorder to a set point. Greene financed the first unit, Ampex’s factory asked for more, and Eventide survived for a while supplying tape-search units to Ampex, along with a two-second delay line for telephone research and a device for dispensing nanolitre quantities of chemical reagents.

Its first audio line came out of an Audio Engineering Society show in New York and an order from Maryland Public Broadcasting: the Instant Phaser and the DDL 1745 digital delay, which gave two channels of up to 200 milliseconds and, the company says, needed “a hundred shift registers and lots of patience.” A later version, the 1745M, used random-access memory — for the first time in an audio product, Eventide believes. The DDL 1745 joined the TECnology Hall of Fame in 2018, according to the company and English Wikipedia.

Manhattan did not last. The company says it spent thirteen years there, latterly in two buildings on either side of a busy street, before moving to an industrial park in suburban New Jersey. Its press releases are now datelined Little Ferry, New Jersey. Eventide Communications, its recording division, says it “began in 1971 in Little Ferry”; the main company history puts the start in New York, and we follow that.

The Harmonizer.

The product that made the name was the H910 Harmonizer. In 1974, the TECnology Hall of Fame essay published for the 2007 inductions recounts, Factor asked his young designer Anthony (Tony) Agnello, the company’s first “degreed” engineer, to build a harmony processor. The prototype shown at the AES show that year was a hand-wired box under a music keyboard, and the Yes singer Jon Anderson tested it. The production H910 followed in 1975, offering pitch shifting of an octave either way, up to 112.5 milliseconds of delay and feedback, for $1,600. The model number, the essay says, nods to the Beatles song “One After 909.”

Its first customer, according to the same essay, was New York’s Channel 5, which used it to bring down the pitch of I Love Lucy reruns that had been sped up to make room for more commercials. Musicians followed: the essay names Frank Zappa, the producer Tony Visconti and Eddie Van Halen, who used a pair of slightly detuned H910s. Eventide filed to register “Harmonizer” as a trademark — English Wikipedia dates the filing to November 1976 — and still prints it with the ® sign. The company calls the H910 “the world’s first commercially available digital audio effects unit”; that is its own claim. The H910 entered the TECnology Hall of Fame in 2007.

Later products built on the same ideas. The SP2016 reverb arrived, the company says, in the first year of the 1980s. The H3000 UltraHarmonizer, dated 1986 in English Wikipedia’s timeline, included a “Dual 910” program that recreated the twin-H910 trick; Soundtoys, the plug-in company started by former Eventide engineers, credits its founder Ken Bogdanowicz, with Bob Belcher and Dave Derr, as the H3000’s designers. Eventide says the H3000 is also in the TEC Hall of Fame. The DSP4000, the Orville and the H8000 continued the rack line. From 2007 Eventide added guitar pedals — TimeFactor, ModFactor and PitchFactor, later the H9 and, in November 2022, the H90 — as well as software plug-ins and the H9000 rack processor.

In 2018 Factor and Agnello received a Technical Grammy, the Recording Academy’s special-merit award for technical contributions, according to Eventide and Wikipedia’s list of recipients.

Effects, studios and documentation.

Studio outboard — the reverbs, delays, compressors, equalisers and preamps that sit in racks beside a mixing console — is a small trade, much of it started by engineers working for themselves. The seven makers in this guide span digital effects, valve processing and licensed recreations of vintage studio equipment.

Two are American digital pioneers of the early 1970s. Eventide began that year in New York City and now dates its press releases from Little Ferry, New Jersey; we found no record of a sale to a larger group. Lexicon began in 1969 as American Data Sciences, took the Lexicon name in 1971, was based in Waltham, Massachusetts, and was bought by Harman in 1993, Harman announced at the time; Samsung completed its purchase of Harman in March 2017.

TC Electronic was founded in Aarhus, Denmark, in 1976 by the brothers Kim and John Rishøj. In April 2015 MusicRadar reported that its parent, TC Group, had been bought by Music Group, the Behringer owner now called Music Tribe.

The analogue makers are smaller. Empirical Labs, founded by Dave Derr, who had helped design Eventide’s H3000, lists a New Jersey address and says all its products are made in the USA. Manley Laboratories builds valve equipment in Chino, California, and was bought in July 2025 by Rockforce Tech Holding, a company founded by Dirk Ulrich, Mix reported. Tube-Tech is the brand of Lydkraft, near Copenhagen. Chandler Limited, which Wade Goeke founded in 1999, is in Shell Rock, Iowa, and the company names him as its owner.

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.

Still in New Jersey, still making Harmonizers.

Eventide has never been only an audio company. Its history describes a profitable sideline in Hewlett-Packard-compatible memory boards, from the late 1970s to the mid-1990s, which began because it needed more memory for reverb research; the Argus moving-map displays for light aircraft, developed after Factor took up flying; and, from the early 1990s, digital voice-logging recorders for broadcasters, police and emergency call centres. That business continues as Eventide Communications, which says it became an independent division within Eventide in January 2023 and sells NexLog recorders.

We found no record of Eventide being sold to a larger group. English Wikipedia described Factor as co-founder and chairman in 2017, and says Agnello went on to become president of the audio division. The company’s releases still come from Little Ferry, where it also advertises in-person jobs. Where its hardware is built is not stated on the product pages we checked, so we do not say.

A practical note: the official sites are eventideaudio.com, eventide.com and eventidecommunications.com. Search results also turn up shop sites using the Eventide name whose link to the company we could not confirm. “Eventide” is also an old English word for evening.

For a design guide, Eventide shows how a single product name — Harmonizer — can carry a company for half a century. Compare Soundtoys, founded by engineers behind the H3000, and Lexicon, its digital-delay rival from Massachusetts. For this guide we use black, a signal red and warm grey with a sans, an unofficial interpretation; no product or logo is reproduced.

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