Accuphase Laboratory, Inc. (originalmente conocida como Kensonic Laboratory, Inc.) es un fabricante japonés de equipos de audio de gama alta con sede en Yokohama, fundado por el antiguo ingeniero de Kenwood Jiro Kasuga a finales de 1972.

Kasuga was not happy with the views of Kenwood relating to the follower of their High-End Supreme 1 unit (1967). He hired some engineers from other prominent brands (Marantz, Luxman) and started Kensonic, with Kenwood as a part owner. Some other connections in the early years of Accuphase exist as well. If you compare the parts used by Kenwood and Kensonic throughout the latter's early years, the familiarities show quite easy: knobs, buttons, tuner dials and the general direction of the design. Accuphase's early PCBs are tagged KENSONIC, too, and the early units bore KENSONIC on their frontplates as well. Until the mid-1990s, Kenwood still owned part of Kensonic. It appears that Accuphase engineers may have had a hand in the engineering of Kenwood's last high-end series (L-A1, L-D1 and LVD-Z1). For example, the Accuphase E-405 and Kenwood L-A1 have very similar volume knobs, side panels, and remotes.

Kensonic's first products were the P-300 amp(lifier), the C-200 preamp, and the T-100 tuner. The E-202 integrated amp and an up-versioned tuner (the T-101) were added soon after. All received very positive reviews in 1973 and 1974. While Kenwood has now abandoned all high-end audio activities, Kensonic carries on with the Accuphase series.

Los productos Accuphase están bien considerados por los entusiastas del audio de gama alta, pero la marca es poco común en EE.UU.. Los productos Accuphase se identifican fácilmente por sus grandes placas frontales de color champán y sus grandes medidores de potencia analógicos dobles, que son similares a los de la respetada marca McIntosh Laboratory (McIntosh es famosa por sus exclusivas placas frontales, que son de cristal serigrafiado y utilizan grandes medidores de potencia analógicos azules).

El nombre ACCUPHASE se adaptó tomando el prefijo ACCU de la palabra "preciso", y combinándolo con FASE, que es un factor importantísimo en la tecnología de audio.