These new converters make a noise sometimes it sounds like a hum but they can make other sounds that reck your piece and quiet. Long about 1998 some genius thought up a way to make the converters cheaper by adding electronics which needs to be cooled, the old ones got warm but no fan was ever needed. So much for that. I also find that noise unpleasant and called the TT Manufacturer they just act dumb like your the only one that has complained about this and you should just learn to live with it. I'm changing my lights inside over to led's to reduce the power draw and put less demand on the converter that should help but the hum will always be there unless you buy a old
TT.