For these measurements, I’m using a capo set of feeler gauges like this set from Grizzly.
- the open action at the 17th fret was .101” on the high E and .083” on the low E.
- the nut seems to be cut just about right. With a capo on the 3rd fret and measuring at the 1st fret, it’s about .002” on the high E and .006” on the low E. Or measured open at the first fret, it’s .015” on the high E and .028” on the low E
- the truss rod was was .011” at the 7th fret, with capo on 1st and finger on 22nd.
- the intonation was completely whacked.
- The pickup heights were carelessly set. The neck pickup was angled to be too high close to the strings on the low side and too low on the high side, resulting in a boomy unbalanced sound.
- The pickup pole pieces were haphazardly adjusted.
So how does Gibson set up its Les Pauls at the factory? In a post to the Gibson Talk forums, Davomite, the final inspector at Gibson Memphis posted the following factory setup notes (I added the purple decimal inch values in parentheses):
Hi I’m David the final inspector at Gibson Memphis. I can give you the factory spec info. on our setups. You will need a mechanics rule to do this properly.
To check neck relief: fret the low E at the first and 15th fret (not 12th) reach to the 7th fret and tap string. There should be a small space between string and fret – no thicker than a piece of paper (about .004”). Do the same with the high E.
ACTION: fret low E at first fret and measure the distance from the bottom of the to the top of the 15th fret. It should be 5/64″ (.078”). Do the same with the high E, measurement should be 3/64″ (.047”). Now measure the string height at the nut; underside of the string to the top of the fret. Low E and A should measure 2/64″ (.0312”), D and G =1.5/64″ (.0234”) and B and high E = 1/64” (.0156”). If string height at nut is correct, recheck string height at 12th fret with strings open. Measurement for low and high E’s should be the same as measurement taken at the 15th.
Pickups: Fret low E at 22nd fret and measure pickup height from underside of string to point on pickup closest to string. Bridge pickup should be 3/64″ (.047”), neck pickup should be 4/32” (.125″). Fret high E at 22nd fret, distance for both pickups should be 3/32″ (.094”).
Play test: Play every string at every fret checking for buzzes. Bend High E string 1 and 1/2 steps, beginning at the sixth fret and ending at 22nd, checking for “choking” and to make sure string stays in nut notch.
In their Gibson Backstage Pass setup tips article (easy to read version here), they recommend adjusting the truss rod so the fretboard is level, and then giving the truss rod nut an 1/8 turn for a hair-width relief.
This Epiphone has a double action truss rod so it’s a bit different: turning the truss rod counter-clockwise adds relief, clockwise removes relief and adds backbow, as usual, but there’s a strange space in between those where the truss rod goes completely loose. Don’t leave the truss rod in that in-between loose state, as it makes the body warble and rattle when playing. Note (thanks Craig!): you’ll need a 4mm Allen wrench for the truss rod- but if you don’t have metric wrenches, a 5/32″ (3.97mm) wrench is close enough.
So, that’s the intended factory setup, which is pretty different from the setup I received! Here’s what I did:
It was fairly painless to adjust the bridge – this Epiphone LockTone Tune-o-matic is machined pretty nicely, and the height and saddle intonation screws all adjust very easily. Public service announcement: always remember to use the right size screwdriver tips to avoid damaging the screws!
I made the following preliminary adjustments, which turned out to be pretty close to the Gibson recommendations:
- adjusted the truss rod for slightly less neck relief, about .008” holding 1st and 22nd. Using Gibson’s method, holding 1st and 15th, this is about .004”
- adjusted the action open at the 17th fret to .062” on the high E and .084” on the low E. Using Gibson’s method, holding 1st and measuring at 15th, this is .047” on the high E and .080” on the low E
- fixed the intonation. The saddle bottomed out on the G string, so I will need to flip the saddle around when I change the strings
- adjusted the pickup heights for balance
- adjusted pickup pole pieces to follow the neck radius
Things left to do:
- flip the G saddle and re-intonate
- scrape, clean and oil the fretboard
- level a few high frets causing some buzz
- polish the frets
Not surprisingly, the Tune-o-matic retainer wire does rattle a bit, so I’ll be replacing this bridge with a Gotoh 1511-N from StewMac. While I’m there, I may get the Gotoh 5740 aluminum stop piece as well, just to see if it makes any difference. I’ll let you know…