List of manufacturers starting with letter O

Oasis

Oberheim

Oboes

Obsbot

Obsidian

ObsidianWire

ocarinamusic

Odisei Music

Oetken Gongs

Oktava

Okura+mute

Old Blood Noise Endeavors

Olli Hess

OLLO Audio

Olympus

Omnibus Press

Omnilux

Omnitronic

On-Stage

One Control

OneOdio

Openhagen

Opsilon

Optima

Orange

Orca

Origin Effects

Ortega

Ortofon

Ortola

Oruga

Oscar Adler & Co.

Oscar Schmidt

Osram

Otamatone

Otto Dürrschmidt

Otto Jos. Klier

Otto Junne Verlag

Otto Link

Otto Musica

Outlaw Effects

Output

Ovation

Oxford University Press

OXI Instruments