A customer recently came in wanting to put replace his standard tuneomatic bridge with an intonated ebony saddle from a floating bridge. Most acoustic archtop guitars have a floating bridge made of wood, which can impart a rounder, more “woody” tone than a metal bridge. This Gibson has a solid wood center block so that the bridge posts could be drilled straight into the top, allowing for a lower neck angle and eliminating the wood bridge base. The hole spacing for the bridge posts was identical, and the saddle height was tall enough to allow for proper string height. The only thing left to do was notch the saddle under each string for correct string spacing.
I first laid out the two outside E strings, locating them evenly over both the fretboard and the pickup’s pole pieces. I then used my handy Stew Mac string spacing ruler to layout the remaining 4 strings. The slots in the ruler get wider moving towards the bass side and are graduated based on string gauge, allowing the strings to be evenly spaced on center. After starting the slots with the proper gauge file to acommodate the string, I strung up the rest of the strings and continued slotting to match the fretboard radius.
Tuned to pitch, the bridge was nearly perfectly intonated. I made some minor adjustment with a file and polished out any imperfections. I was pleasantly surprised at the tonal change and the customer got exactly what he was hoping for. The treble harshness of the metal bridge was gone, and the mellow character of the flatwound strings seemed right at home on this new wood saddle.