(Not sure whether I should have asked this on the pickups forum.) Just got this new fretless bass which came with roundwound strings.. Of course my first act was to change them with flatwounds. However I sadly discovered that the A string sounds noticeably quite (perhaps half the volume) in almost EQ / blend settings . Can't be related to the nut, because I get low volume with open strings as well as any fret(?) position Putting back the original roundwound A string fixes the problem. This made me suspect the bridge - and I noticed that the flatwound A is significantly thicker than the rw A, which causes it not to fit completely into the 'rail' in the bridge, therefore the string sits a bit higher than the others (curiously this is not the case with E or B strings). So I have to try lowering the string, but I don't have an Allen wrench. While I look for one, may I get opinions on this? I still find it hard to believe that lowering that string by that 0.5 - 1mm will actually boost the signal enough to make things equal. Could there be something else wrong with the string/pickup/bridge etc?