WHAT A RELIEF…
Neck relief is often a personal choice. But what happens when you change your strings?
We get lots of questions about neck relief – the slight forward concave bow that allows a pretty buzz-free action. Some players, not to mention makers and repairers, like more relief; others prefer to keep things virtually straight. It’s easy to check. Simply capo your guitar at the 1st fret and hold down the G string (and check the high and low E strings) at the top fret. You should see a slight gap – about the thickness of the top string as a visual guide – between the top of the 8th or 9th fret and the underside of the string. Do the same with the G and low E string. Of course, you can measure the gap with a set of feeler gauges, but developing your own visual ‘gauge’ is your goal. To straighten the neck and reduce relief, you need to tighten the truss rod – and vice versa.
Dropping down from 10s to eights as we’ve done here should slightly reduce the relief in the neck. But do the more flexible eights need more or less relief? I honestly wasn’t sure, and after some research and calls to trusted repairers it’s a bit of a ‘jury’s out’ situation. “I personally think all things should stay the same,” suggests Patrick Eggle, “because the physics is the same and I’m a great advocate of the school of thought that says that once the bridge is set correctly and the relief is set correctly then if you want a higher action you do it with the truss rod. With a lower action you need the neck to be straighter. But Kieran Potts, who does the setups here, would suggest very, very slightly more relief – that’s certainly what he did on the guitars we made for Billy Gibbons last year. I thought they were very elastic band-y, but that was with sevens and a shorter [625.5mm] scale length than what you’re working with there.”
Having double-checked that the frets on my 635mm (25-inch) scale PRS SE were super level, I increased the relief slightly… and then put it back. When I measured it, as I thought, it has minimal relief: 0.127mm (0.005-inch) over the 8th fret with a string height at the 12th of 1.5mm on the high E and 1.8mm on the low E. It’s a great example of how one size rarely fits all and how you actually set your relief as part of your overall setup is really quite personal.