Ok...not completely sure if this is the right place to post this, but... Last week I got my first 12-string bass (it's a Hamer), and up until last night it worked great. Now it's making an odd sort of stressed, clanging noise when the first note of each string is played. Open chords and any other notes are just fine, but those four notes sound just horrible. Does anyone have any idea what the problem might be? I'd appreciate any help Thanks.