Related Clues:

• Rock band booster
• Sound investment for a band
• Evel aid
• One for the roadie
• Increase, with "up"
• Mike gets juice here?
• Intensify, with 'up'
• Show off one's Harley, in a way
• Rock band need
• Concert stage item
• It pumps up the volume
• MLK Jr., for ex.
• Parking garage part
• Performance piece?
• Arena rock need