About the Company
KLH Audio began in 1957 as KLH Research and Development Corporation, founded in Cambridge, Massachusetts, USA, by Henry Kloss, Malcolm S. Low, and Josef Anton Hofmann. The name KLH comes from the initials of the founders.
While KLH is best known historically for loudspeakers and other high-fidelity audio equipment, it did produce reel-to-reel tape recorders during its early innovative phase in the 1960s.
Entry into Reel-to-Reel Recorders
1960s – The Model Forty
KLH’s most notable reel-to-reel product was the KLH Model Forty, introduced in the late 1960s (around 1968–1969).
It was significant because it was one of the first consumer reel-to-reel tape recorders in the U.S. to incorporate Dolby “B” noise reduction, developed through collaboration between Henry Kloss and Ray Dolby. This marked the first use of Dolby technology in a consumer tape recorder.
Features of the Model Forty
The Model Forty typically had a three-motor, three-head design with multiple tape speeds (notably 3¾ and 7½ ips).
It offered robust construction with wooden cabinetry and a metal faceplate, positioning it as a high-performance home recorder rather than a simple dictation deck.
Despite its innovations, the Model Forty was notoriously unreliable in early production runs — with issues in transport relays and other components — which undermined its commercial success.
Associated Models
The company also produced a Model Forty-One reel-to-reel tape deck, which was a later or variant model tied to the same generation of KLH recorders.
Manufacturing and Sourcing
Some historical sources suggest that electronics or assemblies for the KLH Model Forty and Forty-One were sourced from Japanese companies such as Nakamichi, with U.S. assembly and branding under KLH.
While exact production locations varied, the brand’s early tape recorders were engineered as premium domestic machines aimed at the U.S. hi-fi market.
Market Context & Decline
KLH’s reel-to-reel activity appears concentrated mainly around this late 1960s era; it did not become a long-running or broad tape-recorder product line compared with companies like Ampex, TEAC, Akai, or Sony. Unlike major tape recorder manufacturers, KLH used the format to complement its broader hi-fi product portfolio rather than as a core focus.
By the 1970s and 1980s, KLH’s emphasis shifted largely back to loudspeakers, radios, and other consumer audio products, and the reel-to-reel segment faded as cassette decks and other formats grew in popularity.
Company Evolution After Tape Recorders
KLH was sold to Singer Corporation in 1964, then became part of Electro Audio Dynamics (EAD) in 1970, moved to California in 1980, and was acquired by Kyocera Ltd. in 1982. Production for many products (including tape-era equipment) increasingly shifted overseas.
Kyocera eventually stopped manufacturing audio products in 1989, and KLH was sold to other owners. Today it exists as KLH Audio, primarily a loudspeaker and hi-fi brand, now based in Noblesville, Indiana (and with an association with Victrola from 2025).
Legacy in Reel-to-Reel History
KLH’s contribution to consumer reel-to-reel recorders — especially the Model Forty with integrated Dolby noise reduction — is historically notable because it brought advanced recording technology into the home market at a time when reel-to-reel was still considered a premium format. However, its presence was brief and limited to a small number of models, and KLH is far better known for speakers and loudspeaker innovation than for tape recorders.