I'm fed up with adjusting the sound volume for various inputs via my old Sony STR-DG510 AV. Volumes vary dramatically between cd's, dvd's, bluray, freeview channels, freesat channels, hd tv channels etc. (to say nothing about TV commercials!) I'm well out of touch with the world of AV receivers so is there such a thing as an amplifier that allows the sound volume to be set globally so it stays the same whatever the input? I'd be very grateful for advice.