"John (or George, I haven't checked the bible) uses guitar amp tremelo in the bridge arpeggiated sections, which is activated by a footswitch. Going into the first (I think it's the first) bridge [1:08], he accidentally pushes the switch one note early, which gives the big chord a tremelo effect (which I'm sure was untintenional). It sort of sounds like a tape dropout, but isn't. He also kicks in the tremelo for the last two chords of the song [3:19] (and the plucking of the ends of the strings at the close)."