Cracking The Nut
In the second of two pieces, Jamie Dickson speaks to luthier Seth Baccus about how a well-made nut contributes to tone and playability
Last month, we joined Cornwall-based luthier Seth Baccus to discuss how the material your nut is made out of contributes to tone. Seth had some fascinating insights to share on that topic, but then our conversation turned to how the nut is made. The material that your guitar nut is made from is only part of the equation, Seth advises. More important still is the way it has been shaped and cut, which has a critical influence on tuning stability and intonation as well as tone.
“There are a few things to take into consideration,” Seth says of making nuts. “One is that we want no sharp edges anywhere, so I take quite a lot of care in the way it fits into the nut slot and the way it matches the fingerboard, and I also knock off all the [abrasive] edges on the front. If you are sliding down to an E minor chord or something and you accidentally bang the nut, you’re not going to get injured or whatever. You want nice rounded edges. When it comes to depth of the nut slots, I like to have around half the string in the slot and half the string out of the slot. I think if you cut the slots too deep and all of the string is in the slot, you’re just increasing the potential for grabbing. So I think that half-and-half thing seems to work really well.”
Cutting the nut slots precisely is a fine art in itself, Seth continues, and is, in many ways, the most critical operation in making the nut.
“It takes a little bit of practice to really master because the nut files cut very quickly,” Seth says. “So when you’re cutting the slot, you get it down to a rough height at the start and from then on you cut carefully and measure frequently: you make maybe two passes or even one pass through with the file then check it again. We’re talking microns of adjustment. But if you get it just right, it makes the guitar so much easier to play and tuning is a lot more accurate, especially in the lower register.”
As Seth explains, the guitar is a series of managed compromises when it comes to tuning accuracy. As many players will have noticed, chords played in one spot on the neck will sometimes sound out of tune when played in another position. This is because the act of fretting a string stretches it a little, leading to a subtle tendency to sound sharp. So-called compensated nuts make use of an ‘overhang’ to effectively shorten each string very slightly, with the degree of overhang varying according to each string’s particular susceptibility to fretting sharp.
Does Seth set much store by compensated nuts, as compared with the standard variety?
“If you get the nut slot just right, it makes the guitar so much easier to play and tuning is a lot more accurate, especially in the lower register”
“When it comes to depth of the nut slots, I like to have around half the string in the slot and half the string out of the slot. It works really well”
“I’ve built a couple of guitars with compensated nuts. And actually my acoustic guitar had a bit of a wolf note on the G string, so it was a bit of a problem. I spoke to my friend Bill Puplett about compensated nuts, because he’s a bit of a master and has a sort of formula for making them, and I think with that acoustic guitar it really made a big difference. But it’s not a necessity on all guitars. I think it’s something to be taken into consideration if there is an issue.
“If everything else is fine on a guitar, it’s generally not a necessity. Then again, it is quite surprising how big the overhang can be on a compensated nut. It just shows how inaccurate the whole tempered tuning system [that guitars are designed around] actually is,” Seth muses. “But it works, doesn’t it?”
Speaking of the sometimes elusive sources of tuning instability, Seth adds that “it can be a number of things. It’s always difficult with talking about a specific thing like a nut and what influence it has – because, in fact, everything has a knock-on effect. The material the nut is made of, the slipperiness and the nut slots are all going to make a big difference to the tuning stability certainly. And in terms of intonation accuracy, how well the nut slots are cut makes a big difference. But it also matters how accurate the fretting is and how well the frets have been crowned. When you tot it all up together, that’s what makes the difference between an average guitar and a great guitar.” https://sethbaccus.com