Magnificent amplifier unfortunately dropped loudness (8)
I believe the answer is:
imperial
'magnificent' is the definition.
(I've seen this in another clue)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for imperial that I've seen before include "Sovereign - old Russian gold coin - type of beard" , "Majestic - wine bottle" , "Mint --, sweet" , "To do with empire or emperor" , "Magnificent; small pointed beard" .)