Kurt Bloch talks setup and maintenance for electric guitarslearning Advice from a Guitar Tech
Kurt Block knows electric guitars. He has been working on them for three decades. He started out working on guitars in the bands he was in, and nowadays maintains the guitar collection at Gibson’s entertainment relations office in Seattle, one of eight in the U.S. — and 20 worldwide — that the company maintains to put on promotional events and provide artists with Gibson guitars to demo.
This Monday, Bloch will be teaching a free live-streamed seminar for Creative Live, along with Ben Verellen of Verellen Amplifiers, called “Guitarist’s Tech Workshop” (12 PM to 7 PM EST). In it they’ll talk about maintaining and getting the optimal sound from your guitar and amp.
We had the opportunity to talk to Bloch, and he gave us some pointers on guitar maintenance and demystified such issues as string life, cleaning your guitar, adjusting the truss rod and more.
Tell me about the online seminar. What are you going to be covering?
It’s a course on not just upkeep but how to setup a guitar. There's a certain level of things that you can do that really most guitar players are capable of doing and should do to keep their guitars playing well. My theory is that you should be able to play a show, a set, be it 40 minutes or whatever, on a guitar, and unless something bad happens like you bang it into something, you should be able to play the set without having to tune it between every song, or any song, really. If your guitar is setup really well. For most people, and I'm not saying everybody, including myself. Because sometimes something gets bashed around, or someone runs into you. But that kind of stuff notwithstanding, you should be able to play a show without fiddling with things all the time. And a lot of people don't know a good way to put their strings on and a lot of people don't know fairly simple things you can do to keep things working well.
So there are probably a lot of people who are playing out on guitars that are not well setup and they don't even realize it?
There's no doubt about that. I've worked on tons of peoples’ guitars where it's like, "Wow, how can you even play this thing?" And everybody has their own thing. I notice a lot of guitar techs are really bossy. "Don't do that," or "This thing's a piece of shit, it can't be used." Well, no! The guitar has to be “teched” to the style of the person that's playing it.
What are the most common issues that you see in guitars that people bring to you?
Many things that people can actually work on themselves. There are pretty much three things that you check: the bridge, the nut and the neck relief. It’s not beyond the ability of a lot of people to do that. Some people probably think they can’t. And some people can't and shouldn't, but other people can and should. You have to learn a little bit of science behind it and the physics — but there's no manual reading required or anything like that. This is how the guitar makes the note, and if these bridge saddles are not placed right it's not going to play in tune up the fingerboard. And one of the main things about getting a guitar to play in tune is making sure that it can play in tune. And with a lot of guitars now, especially inexpensive guitars, the nut slots are not filed well.
What does that do?
If the nut slots are too high and the bridge saddles are not adjusted right, you could tune it so it sounds good if you're playing a G chord, but then if you play something with an E chord it will sound terrible. So then people say, "Oh well, I’ve got to retune this." And then "Oh, that's better." And then in the middle of the song they change key or play a different kind of chord and it doesn't work and they have to re-tune. So I think part of it is getting so it can be played in a variety of keys.
Can you explain how the bridge pieces affect the intonation? What is the principle behind that?
If you didn't have to actually play the guitar, then the bridge pieces would all be in a line, the same distance from the 12th fret of the guitar as the 12th fret is from the nut. But what happens is that when you actually play the string, you push it down against the fret, and just that action of pushing it that millimeter or whatever will stretch the string. It's no different than if you’re putting vibrato on the string — if you pull or push on the string it will raise its pitch. So, just the act of moving that string so it connects with the fret to play the note that you want, raises the pitch enough that the further the fingerboard you get, the higher the pitch of the note. It will tend to stretch it different amounts. Closer to the middle of the fingerboard, there will be further travel to make that note play.
Between the string and the fret. Since there's a slight relief in the guitar neck, which is put their to keep the string vibration from hitting the fret, generally. Some people will take the relief out — mostly shred people who play real lightly.
Just to be clear, the note makes its sound, not from the string touching the fingerboard between the frets, but the string touching the fret itself.
Yeah. The actual fret is what creates your note. The fingerboard will have some affect on A) how you play and B) the sound of the neck, I reckon. But it's basically there just to support the fret.
Okay, so when you say "relief," you're referring to it bowing in the middle of the neck that’s set by the truss rod?
Exactly. So any time you push on a string it's going to raise its pitch a little and make it sharp. So that is counteracted by those little bridge pieces being a little further back, towards the back of the guitar, from the 12th fret. The distance is increased by a tiny bit. And however much the pitch is raised by you playing the string also depends on the thickness of the actual string core.
So that's why a guitar must be setup for a specific gauge.
Right. Any time you change the gauge of your strings, or change brands — there are tiny differences between the brands — the guitar needs another setup.
So there's an interaction between the relief in the neck and the adjustment of the bridge pieces, and the nut?.
Its totally a balancing act, really, because you can't do one, and then do another thing and not go back and check the other. They all effect each other. It's a bit intimidating for someone who hasn't worked on guitars before.
So in other words, that's why when I tried to fix my intonation years ago, just by adjusting the bridge pieces, I couldn't get it right. Because I wasn't dealing with the other aspects?
Right. You know sort of now what's going to work right for a bridge. If you see a guitar now, and the bridge is out of the pattern that's normally acceptable for playing guitar, you know that you have to get that much closer, before you even look at adjusting the truss rod and checking the other things. Get it close, adjust the truss rod — I'm not a measuring kind of guy. There's a way of fretting the first fret and fretting the note where the neck meets the body. And then checking the relief between the string and the 12th fret. I'm not sure what the measurement of the distance is, but I can see it in my own brain.
So you just eyeball it?
Definitely. That's always worked for me.
So when you look at the neck there's just a little bit of bow in the middle?
Just a little bit. About a millimeter or the thickness of a couple of business cards. A 32nd of a inch, maybe.
And guitars are affected by changes in weather, right?
Especially if your strings are set close to the fingerboard — if your action is low — you will definitely notice a change in the way the guitar plays through the seasons. It is funny to notice. Looking after the guitars in the showroom where I'm at, as the seasons change, it's like, "Oh, 20 percent of the guitars are harder to play this week than they were two weeks ago." Usually in that case, it's like a quarter turn at the most of the truss rod of a guitar. It's really fine tuning, but it just matters so much to make it work well and sound good and make you not get frustrated at shows, if your guitar doesn't stay in tune, is harder to play. On the other hand when the seasons change again, the bow will come back the other way and you'll see a couple of guitars where the strings will be actually touching the fingerboard, or fretting out, because the adjustments you made last season are being counter acted.
How often do you recommend changing strings? Is it all a function of how much you're playing the guitar?
For sure. There's no simple answer to that. If you're breaking strings constantly, then there's probably an issue with something else in your guitar — sharp little bits, something causing a string to break. Other than actually breaking strings, it just depends on how much you play it and how much you perspire. Some people have super-corrosive sweat that will even wreck the chrome-plated parts of a guitar over the course of a year or two. And then there are people who have a light touch and don't sweat and don't dig in and don't trash the strings.
If you have an important gig and you don't want to break a string, is the best thing to change your strings the day of the show?
There again, it depends. Some people are superstitious about that.
In what way?
They never want to change the strings the day that they play. With a properly done string change, and the strings stretched and everything setup right, I would have no problems changing them and playing immediately afterwards. But before I knew how to do that very well, I never would. You'd always want to practice on the strings before you'd go to play a show.
Talk about what pickup height adjustment can do.
There's a lot of wrongs, but there's not one right. In a Gibson guitar, you can generally set the pickup very close to the strings, at least the bridge pickup, where you're typically going to want to get your most output. If you're not playing rock music, your neck pickup, if you have one, might be more important. Generally, get the bridge pickup to be as loud as it can without causing problems, and then adjust the neck pickup so that when you switch to it, it sounds the way you like. It also depends on the output strength of the pickup involved.
What issues can you run into when adjusting pickup height?
You can have problems with neck pickups, especially on a Fender guitar, let's say a Stratocaster with a pickup where the actual magnets are the pole pieces. If you have one too close to the string, the magnetic pull of that pole piece can cause problems. A guitar string is steel, and the magnetic pickup can sense its vibrations. But you know how a magnet will attract steel, and it will stick to it. So if it's too close to the string, it will pull the string. Especially on a Stratocaster's neck pickup, if it's too close to the string, the higher up the fingerboard you play, the closer the string is to the actual pickup, and the more the magnet is going to mess with the vibration of the string. It’s this weird kind of choked, overtone, mystery note sort of sound. You just need to lower that pickup a little bit. But otherwise, you want the pickup to be as close as possible to the strings so that you get the most output from it.
So it's not a concern about the strings actually hitting a pickup if it's raised up too high, it's more the magnetic issue?
Of course you don't want it to hit. There again, you will find that happening if a guitar is out of adjustment. Sometimes that bridge pickup or one of the other pickups will be touching the string. Adjusting pickup height should be one of the last parts of your setup routine.
So if you have one string that's not as loud as the others, it's probably due to the pickup height?
Yeah. And for the most part you want the pickups sitting pretty straight. But not necessarily, you always have to listen to the thing and let the guitar tell you how it needs to be set up. If the low E string is way louder than everything else, then lower that side of the pickup.
What about things like the volume knobs and the jacks? There's no kind of maintenance that you can do on those, right? Other than maybe tightening the nut on the jack plate.
It's really good to keep an eye on the physical tightness of the nuts on those things, because they will get loose, and on different guitars it can be a different amount of a catastrophe if the nut comes off [laughs]. On an archtop like an ES-335, if you lose a knob inside that guitar, or if you lose your output jack into the guitar, you're in bad shape. On an SG or Les Paul or Stratocaster, it's not quite as bad. But you don't want to have it happen right before a show, or right before you play. So if something's getting lose, tighten it, don't wait.
So periodically check the knobs and jacks to make sure everything is tight.
Yeah. And although nobody wants to buy a can of potentiometer cleaner, it’s like $12 or $13 for a little can, you've got to have it. Nobody wants their volume knob to go [makes crackling noise].
Since we're talking maintenance things, lets go back to the strings for a second. Do you recommend wiping them down after playing, or is that only for people who really sweat a lot?
I would recommend it for everybody. Whatever you leave on the guitar — if there's any moisture or oil or whatever — the longer it sits, the worse it's going to get. The end of somebody's finger is pushing down against a wooden board with metal things in it, and the fingerboard can even get nasty. There are tons of people that never clean that.
What do you clean the fretboard with?
My go-to fretboard cleaner is a plastic credit card. I save all the bogus ones I get in the mail, the real plastic ones, not the fake plastic paper ones. They're just right for getting the grime off the board, right up to the frets. I use Gibson fretboard conditioner, but I bet any wood oil would do, and then a regular cloth to clean up all the scraped-off gunk.
How do you know when your frets need to be worked on?
Just looking at them and seeing if there a lot of divots. The first five frets of a guitar usually are the ones that are going to get the most notes played on them. And they get little divots in them first. If you have 20 guitars and you play them all, then the wear to one particular one is not going to be that much. But some people have just one guitar, and they play all the time, and within a year they’re going to start seeing little divots in the frets.
What will those do?
The little divot in the fret is going to do two things: It's going to cause you to have to push the string down further, which will stretch it a little bit, and will affect your intonation.
There’s a way to resurface your frets without replacing them, right?
They call it a “fret level and dress.” What that means is they take the strings off, adjust the neck so it's flat, and then with either sandpaper or some sort of abrasive thing, they sand or file all the frets so they're flat again. So a lot of material will have to come off the ones that are not worn to match the ones that are worn.
So obviously you can only do that a couple of times probably before you need new frets.
It depends on a couple of things: How high the frets are to begin with. Because there's various sizes and shapes of frets. They file them flat with a fret file or some other filing thing, put a new rounded peak on the top of the filed fret, so that once again, the place where the note is addressed is the very peak, the top, middle of the fret. A lot of guitars can easily get a couple of fret dresses before you have to replace the frets.
On the subject of frets, does the size of a fret affect the feel of the guitar?
It's one of the things that affects it the most.
Is there a rule of thumb? I guess obviously a high fret you're going to feel on your fingers more when you're sliding down the neck, right?
Right. It's such a personal preference. A lot of people who are playing fast guitar, want high frets. Some of those '90s shred guitars have super tall frets, so that your touch can be very light to get that note to fret, because your finger doesn't touch the fingerboard at all. It does help a lot of people to play faster if they have super tall frets. Whereas, if you have super tall frets, and you're playing rhythm guitar, it almost works in the opposite way. It'll mess with your grip on the guitar neck to play chords. There's a balance between how your guitar works and what your technique is. And you have to make that work in order to get things to play in tune.
Can you think of anything else that you would recommend that guitarists keep an eye on, from a maintenance standpoint?
One thing that I see a lot of that makes it tough to work on a guitar, is corrosion in the bridge area. It's good to keep an eye on cleaning the bridge pieces and the pickup. Try to keep things clean a little bit. A lot of people just don't pay attention to it, so then it comes time to do a little adjustment on the guitar and your bridge pieces are corroded and rusted and stuck together. You get bridge saddles that you can't adjust anymore, because there's been so much gunk on them for so long that they're rusted or corroded, and the little screw pieces don't turn anymore.
How do you recommend cleaning those parts?
As routine maintenance, just wipe them off. And be aware of it. And you don't have to wipe off your bridge saddle screws every show [laughs], but just be aware of it. If you have a guitar in that hasn't been worked on for years and you take the strings off, you have to take each screw out and clean it and take the whole assembly out. Just be aware of things and look at the mechanical parts of the guitar and keep an eye on them. If something looks like it's getting gummed up or corroded or whatever, clean it up.
Are there any products that work well for doing that.
If you're taking things apart, clean the parts with a little WD-40 or something like that. The screws and the little metal parts, just spray them with a little WD-40 and wipe them off.