EarTrumpet - Volume Control for Windows
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Volwheel - VolWheel is a little application which lets you control the sound volume easily through a tray icon...
Voicemeeter Banana - VoiceMeeter Banana, the Advanced Virtual Audio Mixer by V.Burel
Volti - Volti is an GTK+ application for controlling audio volume from system tray/notification area.
iVol - iVol is a program you can use to adjust the sound volume of your computer in an extremely easy way.