Related Clues:

• Charges (up)
• Solid-state, e.g.
• Connection for an electric guitar
• Unit of elec. current
• Booster of a rock band
• Guitar boosters
• Rock band's item
• Concert's sound boosters
• Sound intensifier
• Increase, with ''up''
• Some were for The Byrds
• Concert blocks
• A little juice?
• Gear for gigs
• Speaker's adjunct