Brands
- A & S
- A.Y.A Tokyo Japan
- A/DA
- aat
- AboveGroundFX
- Absolutely Analog
- Ace Tone
- Acid Fuzz
- acidvoice
- Addrock
- Aguilar
- Akai
- Alex Saraceno (Dirty Boy)
- Alexander
- Allied Radio - Chicago
- Amdek
- Ampeg (Amplifiers and Effects)
- Amptweaker
- AMT Electronics
- Analogman
- analoguehaven
- Andre
- Ansom
- Antelope
- Apollo (Shin-ei)
- Applause
- Applied Co.
- Aramat Effects
- Arbiter England
- Arc Effects/USA
- archangele1
- Aria
- Aria (Rack Mounted Effects)
- Arion
- Artec
- Asama
- ASE
- Ashbass of Pennsylvania
- Asonix
- Astro Amp
- Atomic
- Audible Disease
- AUDIO DESIGNS
- Audiotech
- Auralux Amplification, LTD
- Austin
- Austone Electronics
- Avora (Shin-ei)
- Axe (Rebranded Arion Perhaps)
- Axis Research
- AXR
- AXS