Under construction

Please note that this is a company listing not a brand listing, for the latter see: Brands & trademarks

Signal processors for pro-audio and musical instrument use

Signal processors
Acoustic & Lighting System — A-Designs Audio — Analoge + Digitale Tonstudiotechnik — AMH Sales — AMS Neve — Audio 4 & C — BBE Sound — Behringer — BSG Technologies — BSS Audio — Buzz Audio — Carvin — Chameleon Labs — Chandler Ltd. — Cloud Electronics — Crane Song — Dangerous Music — Digitech — Drawmer — Drip Industries (Kit) — Equipos Europeos Electronicos S.A.L. — Feilong — GCI Tecnologies — Geoffrey Daking — George Massenburg Labs — GHS Strings — Guangzhou Tasso Pro Audio Co. — Harrison Laboratory — Joeaudio Ltd. — LAB Gruppen — Lipinski Sound (mod only) — LT Sound — Lydkraft Aps. — Midas — Nabro Able LLC — New Sensor Corporation — Numark — Oram Professional Products — Orosys — OTO Machines — Panasonic — Proel — Quantec — Q2 Audio — Radial Engineering — Radio Design Labs — Roland — Rupert Neve Designs — Salzbrenner Stagetec — Shep Associates — Skibbe Electronics — Sound & Music Distribution — SPL — Stamer Musikanlagen GmbH — Steinigke Showtechnic — Studioking — TC Electronic — TL Audio — Tropical Music Export Enterprises — Unika — Universal Audio — Valerio Riccelli — Vintech Audio — Z-Systems.

Companies that have made signal processors in the past
Aardvark Computer Systems — Design Engineering (Wokingham) Ltd. — Fletcher ElectroAcoustics — Fostex — Hoshino Gakki — IRP Professional Sound — Lake Technology — MXR Innovations — Texol Technical Solutions PLC — Ursa Major — Zoom Corp..

Multifunction signal processors
Trinnov Audio
These are used in specific cases such as digital cinemas where there is a requrement for multiple types of signal processing at once but not a need for much user interaction.

Modular signal processors
Analoge + Digitale Tonstudiotechnik — AMH Sales — Audio & Design Reading — Buzz Audio — Chandler Ltd. — Lipinski Sound — Lydkraft Aps. — Radial Engineering — SPL — Vintech Audio (Mic pre only).

Companies that have made modular signal processors in the past
IRP Professional Sound.

Equalisers
Aclon — Acoustic & Lighting System — A-Designs Audio — Analoge + Digitale Tonstudiotechnik — Amate Electroacústica S. L. — AMH Sales — AMS Neve — BBE Sound — Behringer — Buzz Audio — Chandler Ltd. — Crane Song — Dangerous Music — Digitech — Drawmer — Equipos Europeos Electronicos S.A.L. — Feilong — GCI Tecnologies — Geoffrey Daking — George Massenburg Labs — Guangzhou Tasso Pro Audio Co. — JD-Media — Harrison Laboratory — Hills Sound, Vision & Lighting — International Audio Group — Ivie — Joeaudio Ltd. — Lake Technology — Lydkraft Aps. — Midas — Ningbo Yinzhou Jia Er Audio — Ningzi Electronic Manufacturing Factory (OEM Only) — Numark — Oram Professional Products — Panasonic — Proel — Radial Engineering — Radio Design Labs — Rupert Neve Designs — Sabine — Seikaku — Shep Associates — Sound & Music Distribution — SPL — Steinigke Showtechnic — Studioking — Tachai — Tropical Music Export Enterprises — TL Audio — Unika — Yorkville Sound — Wunder Audio — Z-Systems.

Companies that have made equalisers in the past
AB International Electronics — AVM-IRP — Fletcher ElectroAcoustics — Fostex — Howland-West — IRP Professional Sound (transversal only) — Malcolm Toft Associates — MicroAudio (Programmable) — MXR Innovations — Roland — Texol Technical Solutions PLC.

Crossovers, feedback eliminators, room correction units & other PA signal processors
Aclon — Acoustic Technologies Electronics — Acústica F. E. S. — Adamson — Amate Electroacústica S. L. — APG France — Audio 4 & C — Behringer — BBE Sound — BSS Audio — Camco (Modules only) — Carvin — Cine Care — Coda Audio — Comercial Electronica Studio-2 — Conrad Electronic — Digitech — Ecler — Equipos Europeos Electronicos S.A.L. — Equipson — Feilong — Ivie — GCI Tecnologies — Guangzhou Sawada Audio Equipment Co. — Guangzhou Tasso Pro Audio Co. — International Audio Group — Idex Ltd. — JCL Production S.L. — JD-Media — LAB Gruppen — Lax — Loud Technologies — Lyd og Lys Norge AS — Lynx Pro Audio — Meyer Sound — Ningbo Yinzhou Jia Er Audio — Ningzi Electronic Manufacturing Factory (OEM Only) — Numark — Proel — Radio Design Labs — RCF — Sabine — Seeburg — Seikaku — Stamer Musikanlagen GmbH — Steinigke Showtechnic — Studioking — Tannoy — Trinnov Audio — Tropical Music Export Enterprises — Unika — Void Acoustics — Xilica Audio Design — Yorkville Sound.

Companies that have made crossovers & other PA signal processors in the past
Lake Technology — Martin Professional.

Voice channels (Recording channels/Channel strips)
AMH Sales — Buzz Audio — Drawmer — Grace Design — Joeaudio Ltd. — Lydkraft Aps. — Oram Professional Products — SPL — Stamer Musikanlagen GmbH — Universal Audio — Vintech Audio — Yorkville Sound.

Companies that have made voice channels in the past
Behringer.

Effect & utility pedals
Aguilar — AMH Sales — Australis Music — BBE Sound — Behringer — Belcat — Brian Barnett — Brian Wampler — Chandler Ltd. — Conrad Electronic — D'Andrea — Day's Corporation — Digitech — Dunlop Manufacturing Inc. — East Sound Research — EBS (Bass only) — Ernie Ball — Evetscorp — F Bass — Fender — Fernandes — Geo Woo Musical Instrument — GHS Strings — Gig-FX — Göldo Music — Gorilla Inc. — GTRC Services — Hiwatt UK Ltd. — Hoshino Gakki — Intelli — JS Technologies — Kaare E. Festvog — Kevin Randall — Korg — Kyung Nam Electronics — Lars Vad Andersen — Line 6 — Malekko Heavy Industry — Marshall — Meiser Electronics — Moog Music — New Sensor Corporation — Nicholas Harris — Nigel J Butters — Oleg U. Basyrov — Orosys — Paolo Mazza — Parsek Srl. — Port City Amplifiers — Radial Engineering — Red Witch Analog Ltd. — Rivera Amplification — Robert E. Starr Jr. — Roland — Seymour Duncan — Schaller — Shanghai Chaobo Musical Instruments Co. — Skreddy Pedals — Sonicware — Sound Enhancemnt Products — Sound & Music Distribution — Source Audio — Stamer Musikanlagen GmbH — Steinigke Showtechnic — Steve Miller — SubDecay Studios — TC Electronic — TecAmp — Ueno Kaihatsu Center — Visual Sound — Vocu — Whirlwind — Zachary Music — Zinky Electronics — .

Companies that have made effect pedals in the past
Design Engineering (Wokingham) Ltd. — Joseph F. Naylor — Prince Tsushinkogyo Co. Ltd. — Red Tree Music Inc — Stringer Industries — Yorkville Sound.

Multieffects
Behringer — Digitech — Guangzhou Tasso Pro Audio Co. — Korg — Midas — Panasonic — Roland — Zoom Corp..

Companies that have made multieffects in the past
Hoshino Gakki — Yorkville Sound.

Guitar/Bass oriented multieffects
Behringer — Digitech — East Sound Research — GHS Strings — GTRC Services — Korg — Line 6 — Roger Linn Design — Roland — Shanghai Chaobo Musical Instruments Co. — TC Electronic — Zoom Corp..

Companies that have made Guitar/Bass oriented multieffects in the past
Hoshino Gakki — Yorkville Sound.

Touch and gesture controlled desktop FX processors
Korg — Source Audio.

Companies that have made touch and gesture controlled processors in the past
Roland.

Guitar/bass amplifier & cabinet simulators
Orosys — SPL.

DI boxes with built in guitar amp or cabinet emulators
Behringer — Conrad Electronic — Radial Engineering.

Organ specific signal processors
Harrison Laboratory.

DJ isolators, effects loops and other DJ specific effect processors and utility products
Steinigke Showtechnic.

Companies that have made plate reverbs in the past
Studio Technologies.

Upgrade parts for plate reverbs
James C. Cunningham.

Companies that have made stereo converters and simulators in the past
Studio Technologies.