Related Clues:

• It pumps up the volume
• Part of the fam.
• F on a physics exam
• Brother or aunt: Abbr.
• Bro., for one
• Performance piece?
• Arena rock need
• Lightbulb word
• Make loud
• Gig component
• One could go up to 11 in 'This Is Spinal Tap'
• Item of concern in a sound check
• Xmas visitor, say
• Sound booster at a concert
• Rock booster