WGuitar amplifier
WAmpeg
WAshdown Engineering
WBehringer
WBlackstar Amplification
WDean Guitars
WDiezel
WDumble Amplifiers
WEcholette
WEden Electronics
WElectro-Harmonix
WFender Musical Instruments Corporation
WGabriel (amplifiers)
WGibson
WGjika Amplification
WHH Electronics
WHiwatt
WJim Kelley Amplifiers
WKona Guitars
WKay Musical Instrument Company
WKustom Amplification
WLaney Amplification
WMagnatone
WMagnetone
WMarshall Amplification
WMatchless Amplifiers
WMesa Boogie
WMultivox Premier
WPeavey Electronics
WPhonic Corporation
WPignose
WPRS Guitars
WRandall Amplifiers
WSuhr Guitars
WSupro
WSWR Sound Corporation
WTHD Electronics
WTōkai Gakki
WTone King
WTrace Elliot
WTraynor Amplifiers
WVoodoo Amplification
WVox (musical equipment)
WWatkins Electric Music
WYamaha Corporation
WYorkville Sound