i have a les paul. on low frets, the sustain is good. but on high frets, the sustain is a little bit less than the average guitars or les pauls. the les paul does not have a specific dead spot. just the overall sustain especially on high frets are short. i guess... the pickup height, the ABR1 bridge or the tailpiece can make the problem. but don't know what is the exact reason. i think the pickup height is not so close to the strings. though i set it up to low action, (high E 1.25mm at 12th, low E 1.5mm) i cannot hear unusual buzzings. once i replaced the bridge and the tailpiece to Faber, which has locking design. it make the sustain a little bit longer. but the overtone disappeared. what can be the reason? what can be the solution?