Related Clues:

• Unit of current, informally
• Acoustic guitarist's lack
• Raise, with 'up'
• Roadies' load
• Item in a roadie's burden
• AC unit
• Excites, with 'up'
• Music box
• Gear for a roadie
• Rock requirement
• Electrical measures
• Rock concert blasters
• Measure of current
• It helps pump up the volume
• Cousin of the speaker?