Manufacturers:
- A & R Cambridge
- A.B.I. Electronics
- AAron Corporation
- ABB Goerz
- Accuphase
- acdc electronics
- Acer
- Acterna
- ADC Corporation
- Adcom
- ADi Communications
- Adret Electronique
- ADS Analog and Digital Systems Inc
- Adtech Inc.
- Advance Instruments
- Advanced Electronics Applications
- Advantest Corporation
- AEG
- Aeroflex
- Agilent
- AIE Automated Industrial Electronics
- Ailtech
- Airborne Instruments Laboratory
- Airzone
- Aiwa
- Akai
- AKG Akustische und Kinogeräte GmbH
- Akira
- Albrecht
- Alesis
- Alinco
- Allen & Heath
- Alliance
- Allied Radio
- Alpine
- Altec Lansing
- Amalgamated Wireless
- Amana
- Ameco American Electronics Corp.
- American Electronic Laboratories Inc.
- American Reliance Inc.
- Ameritec
- Ameritron
- Ametek Advanced Measurement Technology
- Amp Supply
- Ampeg
- Ampex
- Amphenol
- AMPI
- Amplifier Research
- Amstrad
- Analogic
- Andeen Hagerling
- Angelantoni Industrie
- Annecke
- Anritsu
- Antenna Mart
- AOC
- AOR Ltd.
- Aphex Systems LTD
- Apollo Health Inc.
- Apple
- Aprilaire
- ARP Instruments Inc.
- AS S.P. Radio
- Associated Research Incorporated
- Astatic
- Astor
- Astron Corporation
- AsusTEK Computer
- Atari
- Ateliers de Montages Electriques
- Audio Precision
- Autek Systems Corporation
- Automated Processes Inc.
- Avantek
- AVO
- Axon Instruments inc
