Audio manufacturers
- Klevgrand
- Klingspor
- Klowra
- KMA Audio Machines
- Koch Amps
- Kodamo
- Kolberg
- Korg
- Kramer
- Kramer Guitars
- Krinner
- KRK
- KS audio
- KS Digital
- Kühnl & Hoyer
- Kurzweil
- L.R.Baggs
- La Mancha
- LAB Gruppen
- Lab4Music
- LaCie
- Lake
- Lake People
- Lakewood
- Lakland
- LaLique
- Lambda Synthetics
- LANDR
- Larry Carlton
- Lauten Audio
- LAVA Music
- LD Systems
- Le Fay
- Lead Foot
- Leaf Audio
- Leapwing Audio
- Lectrosonics
- Lefima
- Legator
- Lehle
- Lennar Digital
- Leolani
- Lewitt
- Lindell Audio
- Lindy
- Line6
- Listen Technologies
- LiveLoop
- Locomotive Audio
- Looptrotter
- Lothar Semmlinger
- Lounsberry Pedals
- Lovepedal
- LP
- LPD Pedals
- LSL
- Luca Zerilli
- Ludwig
- Luna Guitars
- LunaStone
- M-Audio
- M-Live
- MÄAG
- MAAT
- Mackie
- Mad Professor
- Magewell
- Magix
- Magma
- Mahalo
- Maintronic
- Majella Audio
- Make Noise
- Malekko
- MalletKAT
- Manikin-Electronic
- Manley
- Manuel Rodriguez
- Maono
- Mapex
- Marantz Pro
- Marcus Miller
- Marian
- Marimba One
- Markbass
- Marleaux
- Marschpat
- Marshall
- Marshall Electronics
- Martin Böhme
- Martin Foag
- Martin Guitar
- Master Bucur
- Maton
- Maxon
- Maybach
- Mayer EMI
- Mayones Guitars
- MB Music
- McDSP