I bought a new Korg M50 from American Musical Supply in October. It has started making some kind of weird sustained phaser-like sound after I hit a note - almost like a wash - and just on some sounds. Even basic ones like Grand Piano. And on some timbres, it happens on some keys and not others. It seems to get much worse as I play notes lower on the keyboard. On some patches it's only certain sections of the keyboard, which makes no sense to me. I'm stumped - I did a full factory reset and it made no difference.
Any suggestions before I take it in for service? I'd really rather not be without it for an extended period of time.