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

Integrated guitar amplifiers (Combos)
Argos — Armadillo Enterprises — Atelier Maurice Dupont — Audio Electric Research — Australis Music — Behringer — Belcat — Carvin — Conrad Electronic — Cor-Tek — David E. King — David Gries — Digitech — East Sound Research — Engl — Enrique Keller — Fender — Fernandes — Gabriel Sound Garage — GHS Strings — Gibson Guitar Corp. — Gorilla Inc. — Göldo Music — GTRC Services — Guangzhou Pearl River Piano Group Co. — Hanser Music Group — Hayden — Hiwatt UK Ltd. — Hoshino Gakki — Intelli — International Audio Group — Jack Anderson — KMC Music — Korg — Krank Amplification — Laboga — Laney — Line 6 — Loud Technologies — Maj Electronic — Marshall — Maxtone — Medeli — Mesa/Boogie — Mirr Music Co. — Morgan Instrument — Paolo Mazza — Parsek Srl. — Paul Reed Smith Guitars — Rivera Amplification — Roland — Shanghai Chaobo Musical Instruments Co. — Sejung Musical Instruments Co. — Shinos — Stamer Musikanlagen GmbH — Steinigke Showtechnic — Sung-Eum Music Co. — Team International Co. — Tokai — Unika — US Music Corporation — Waleed Rajab Est — Warwick — Wienbrock — Yorkville Sound — Zinky Electronics — ZT Amplifiers.

Companies that have made integrated guitar amplifiers in the past
David Wexler & Co. — Evetscorp — J. E. Dallas & Sons — Joseph F. Naylor — M & G Amplification — Naylor Engineering — Prince Tsushinkogyo Co. Ltd. — Proel — Red Tree Music Inc — SD Systems.

Guitar amplifier heads
Armadillo Enterprises — Attila Audio — Australis Music — Behringer — Belcat — Carvin — Custom Audio Electronics — Czech Music LLC — David E. King — East Sound Research — Engl — Fender — Fernandes — Gabriel Sound Garage — GHS Strings — Göldo Music — GTRC Services — Guangzhou Pearl River Piano Group Co. — Hanser Music Group — Hayden — Hiwatt UK Ltd. — Hoshino Gakki — International Audio Group — Jack Anderson — JS Technologies — KMC Music — Korg — Krank Amplification — Laboga — Laney — Lars Vad Andersen — Line 6 — Loud Technologies — Maj Electronic — Marshall — Mesa/Boogie — Milan Vaskovic — Morgan Instrument — Nigel J Butters — Paolo Mazza — Parsek Srl. — Paul Reed Smith Guitars — Port City Amplifiers — Rivera Amplification — Shanghai Chaobo Musical Instruments Co. — Stamer Musikanlagen GmbH — Ted Stevenson — US Music Corporation — Warwick — Wienbrock — Yorkville Sound — Zachary Music — Zinky Electronics.

Companies that have made guitar amplifier heads in the past
Joseph F. Naylor — M & G Amplification — Naylor Engineering — Proel — Stevenson Guitars.

Microheads
Diago.

Guitar pre-amplifiers
Basslab — Bravo Audio — Custom Audio Electronics — GHS Strings — Paolo Mazza.

Companies that have made guitar pre-amplifiers in the past
Roland — Parsek Srl. — Proel.

Pedal power amps
New Sensor Corporation — Nigel J Butters.

Guitar amplifier cabinets
Armadillo Enterprises — Atelier Maurice Dupont — Australis Music — Behringer — Belcat — Carvin — David E. King — East Sound Research — Engl — Fender — Fernandes — Gabriel Sound Garage — Göldo Music — GTRC Services — Guangzhou Pearl River Piano Group Co. — Hanser Music Group — Hayden — Hiwatt UK Ltd. — Hoshino Gakki — International Audio Group — Jack Anderson — JS Technologies — KMC Music — Korg — Krank Amplification — Laboga — Laney — Lars Vad Andersen — Line 6 — Loud Technologies — Maj Electronic — Marshall — Mesa/Boogie — Morgan Instrument — Nigel J Butters — Paolo Mazza — Parsek Srl. — Paul Reed Smith Guitars — Port City Amplifiers — Rivera Amplification — Shanghai Chaobo Musical Instruments Co. — Scumback Speakers & Cabs — Stamer Musikanlagen GmbH — Ted Stevenson — US Music Corporation — Warwick — Wienbrock — Yorkville Sound.

Companies that have made guitar amplifier cabinets in the past
Brooklyn Gear — EbEn Acoustics Lab — Joseph F. Naylor — M & G Amplification — Naylor Engineering — Proel — Stevenson Guitars.

Portable guitar amplifiers
Armadillo Enterprises — Belcat — Dean Markley — Evetscorp — Fender — GHS Strings — Gorilla Inc. — Guangdong Takstar Electronic — Guangzhou Pearl River Piano Group Co. — Hoshino Gakki — Izzo — Korg — Laney — Loud Technologies — Marshall — Roland — Steinigke Showtechnic — ZT Amplifiers.

Companies that have made portable guitar amplifiers in the past
Prince Tsushinkogyo Co. Ltd. — Proel.

Headphone guitar amplifiers
Armadillo Enterprises — FiiO — Intelli — Korg — New Sensor Corporation — Ueno Kaihatsu Center.

Companies that have made headphone guitar amplifiers in the past
Evetscorp — Prince Tsushinkogyo Co. Ltd..

Guitar USB interfaces
Behringer.

Acoustic guitar amplifiers
Armadillo Enterprises — Ashdown Engineering — Audio Electric Research — Australis Music — Behringer — Belcat — Conrad Electronic — Fender — Fishman — Guangzhou Pearl River Piano Group Co. — Korg — Hanser Music Group — Hoshino Gakki — Intelli — KMC Music — Korg — Laney — Loud Technologies — Marshall — Morgan Hill Music — Morgan Instrument — Parsek Srl. — Roland — Shanghai Chaobo Musical Instruments Co. — Sung-Eum Music Co. — Trace Elliot — Walker Labs — Yorkville Sound.

Companies that have made acoustic guitar amplifiers in the past
Enrique Keller — Evetscorp — Proel.

Acoustic guitar pre-amps
Fishman.

Integrated bass amplifiers (Combos)
Armadillo Enterprises — Ashdown Engineering — Audio Electric Research — Australis Music — Behringer — Belcat — Carvin — Conrad Electronic — Digitech — EBS — Enrique Keller — Fender — Gallien-Krueger — GHS Strings — Gibson Guitar Corp. — Gorilla Inc. — GTRC Services — Guangzhou Pearl River Piano Group Co. — Hanser Music Group — Hevos — Hiwatt UK Ltd. — Hoshino Gakki — Intelli — International Audio Group — KMC Music — Korg — Krank Amplification — Laney — Line 6 — Loud Technologies — Marshall — Maxtone — Mesa/Boogie — Parsek Srl. — Roland — Shanghai Chaobo Musical Instruments Co. — Sejung Musical Instruments Co. — Stamer Musikanlagen GmbH — SR Technology — Steinigke Showtechnic — Sung-Eum Music Co. — Team International Co. — TecAmp — Trace Elliot — Tropical Music Export Enterprises — Unika — US Music Corporation — Warwick — Yorkville Sound.

Companies that have made integrated bass amplifiers in the past
Evetscorp — J. E. Dallas & Sons — Prince Tsushinkogyo Co. Ltd. — Proel — Red Tree Music Inc.

Bass amplifier heads
Aguilar — Ashdown Engineering — Audio Electric Research —Australis Music — Behringer — Carvin — East Sound Research — EBS — Fender — Gallien-Krueger — GTRC Services — Hanser Music Group — Hevos — Hiwatt UK Ltd. — Hoshino Gakki — International Audio Group — KMC Music — Krank Amplification — Laney — Lars Vad Andersen — Line 6 — Loud Technologies — Maj Electronic — Marshall — Mesa/Boogie — Michael Arildskov Jensen — Parsek Srl. — SR Technology — TecAmp — Trace Elliot — Unika — US Music Corporation — Walter Woods — Warwick — Yorkville Sound — Zinky Electronics.

Bass pre-amplifiers
Basslab — BBE Sound — GHS Strings — Ken Smith Basses (pedal) — Parsek Srl. — Warwick.

Companies that have made bass pre-amplifiers in the past
Brian Barnett.

Bass amplifier cabinets
Acme Sound — Aguilar — Ashdown Engineering — Australis Music — Behringer — Carvin — East Sound Research — EBS — Fender — Francis E. LeJeune — Gallien-Krueger — GTRC Services — Hanser Music Group — Hevos — Hiwatt UK Ltd. — Hoshino Gakki — International Audio Group — Jörg W. Schröder — KMC Music — Krank Amplification — Laney — Lars Vad Andersen — Line 6 — Loud Technologies — Maj Electronic — Marshall — Mesa/Boogie — Michael Arildskov Jensen — Parsek Srl. — Stamer Musikanlagen GmbH — Steinigke Showtechnic — TecAmp — Trace Elliot — US Music Corporation — Warwick — Yorkville Sound.

Companies that have made bass amplifier cabinets in the past
Brooklyn Gear — Proel.

Acoustic bass amplifiers
Gallien-Krueger.

Acoustic bass pre-amps
Fishman.

Subsonic enhancers (Pleasure boards)
TecAmp.

Keyboard amplifiers
Australis Music — Behringer — Conrad Electronic — Korg — Laney — Medeli — Roland — Shanghai Chaobo Musical Instruments Co. — Tropical Music Export Enterprises — Yorkville Sound.

Companies that have made keyboard amplifiers in the past
Evetscorp.

Home use piano amplification & sound systems
Burgett Inc..

Console/Church organ loudspeaker systems
Ahlborn Organs — Roland.

Doppler amplifiers
Motion Sound — Suzuki Musical Instruments.

Drumkit amplifiers, monitors and amplifier systems
Australis Music — Belcat — Medeli — Roland.

Multipurpose amplifiers
Australis Music .

Amplifier road cases and trunks
SKB.

Amplifier stands
Steinigke Showtechnic.

Power soakers
SPL — .