Workshop: Bad Intonation on '60s Gibson Acoustics

Ever wonder why the adjustable-saddle Gibsons never sound in tune "as-is?" Check out the "lightning-bolt" of how I compensated the new ebony saddle for this '66 J-50 as compared to the original, terrible-sounding ceramic one. The ceramic bridge puts compensation on a straight line in the middle of the saddle.

Actual (measured) compensation puts the proper break points at the saddle's rear for the high B&E and more or less down the middle-rear for the EADG strings. It's very common for Gibson bridges from the time to be off 1/8" or more (sharp) for the high E string and quite flat for the low E.

Weird stuff!

Martin didn't really get it any better, though, as it's very common for same-period Martin bridges to be off by 1/16" or so on the treble too sharp and the saddles aren't wide enough to really compensate well for the bass side.