Related Clues:
- Device used to increase sound
- Very gently put paper inside electronic device
- A PA will require some gain from this
- Electronic equipment to increase signal strength
- Intercom component
- Sound-system component, sometimes
- Box near a mic
- Audio engineer's device
- Sound signal booster, for short
- Electrical signal booster
- Pair filmed briefly moving part of roadie’s kit?
- Device increasing loudness