My 303 occasionally 'spits' ie a very short, intermittent buzz which lasts less than half a second. The music behind the noise remains completely undisturbed though so it's probably not laser/disc mistracking. Discs are read very quickly after insertion, less than a couple of seconds.
Leave the player running for half an hour or so and all this goes quiet, as though it's been warming up.
Richard.
Round & round bits: LP12/Cirkus/Kore/Herc II/Roksan Nima/Hana EL
Megabits: Bluesound Node 2i/TEAC UD-H01 dac
Making it louder bits: Phonostage: Dynavector P75 Amp: Cyrus 8vs/PSX-R Speakers: Royd Sintra II
Connecting it together bits i/c's: Flashback Premier. Speaker cables: Van Damme Hifi