Projects and Musings

Jaguars and Jazzmasters - a highly strung issue!


Over the last few months I've had a few of the 'Offset' Fenders through the door for service. Jaguars and Jazzmasters, they have that really funky shape which has become synonymous with the alternative music scene. Johnny Marr was a Jaguar player for instance, as were Elvis Costello and Robert Smith I think. Kurt Cobain played a Jaguar (and a short scale Mustang too), and they are much loved by Indie and other bands that stay out of the 'Classic Rock/Blues' genre that dominated guitar markets for years.

The Jazzmaster was the original, first issued in 1959 with the Jaguar coming a few years later. I've had originals in the workshop, but not often. Mostly I see the reissues that came over the last 20 years. They seem more popular now than they were in their original format. Both share the Rhythm/ Lead split circuit, but the Jaguar had the chrome plates and the extra switches on the Lead Circuit.

One thing they share in common is the very slim feeling neck, one of least chunky in the Fender range that I remember. It's one of the primary reasons why they're so popular I suspect.

So, what's the big deal with them - are they great or a historical misstep that gained cult status?

Cool look, quirky yet attractive

They certainly have a very unique sound. I don't think they respond that well to heavy distortion, but they have a special resonance that I don't think anything else has. If that's a sound you like, you really like it.

Nothing else looks quite them either - that funky retro 'modernist' chic of the late 50's and 60's Americana. If you set them up right (and deal with the bridge), then they can be pretty reliable. The offset waist design is very different to the Strat or Tele, and has more in common with Gibson's Firebird (non reverse). The access to different tones at the flick of a switch is also an uncommon feature amongst its contemporaries.

The Limits of the Big Cat

Those switches. They tend to get rubbish in them and get intermittent, and of course they're a nice repository for condensation. Fortunately they're quite easy to get hold of now in the growing spare parts market on the web. They've always been available through electronics spares mail order of course, because they are just a standard switch used by a number of low tech devices. Just like the original Fender 5 way blade switch which was designed to run the Slow/Fast/Stop not of something like the Leslie Speaker (which they are still used on), but a washing machine.

Then there's the Rhythm circuit itself. The pots are mounted sideways, which can make them a little more difficult to clean out quickly. And to add to that you have to take the bridge off to get to the electronics on most Jazzmasters, so as a repair guy who has to do some quick turnaround stuff for touring musicians, that can be a pain on a Jazzmaster (because you have to set up the bridge again to clean out a pot). Even the modern ones with tune-o-matic bridges require the bridge posts to be removed from the body because the holes in them aren't big enough to just slide them over the top. Lots of people don't use the switched circuit and just bypass it, especially on Jaguars - just because they tend to hit the switches by accident.

The tremolo. Just leave it alone. Don't go there. Take the arm out and behave yourself. OK, that's a bit harsh, it can work very well. But you do have to make sure that you have that bridge sorted out well and don't go to crazy with it. A lot of writers tend to suggest throwing away the bridge on the original design ones, which reduces or removes the unwanted motion on the pins depending on what you fit. The newer iterations (non vintage repros) have standard tuno'matic - but these are still better replaced with a high quality roller, which actually isn't an expensive job.

But the big potential problem is the neck. A lot of Jaguar and Jazzmaster players don't tend to be big string benders, so they get their tone with a set of 11's or 12's, which gives real warmth and girth to the sound. And that's where the real problems of the big cats start.

Trussed up and strung out

Over the last few months I've encountered three different models of Jazzmaster/Jaguar. All three are suffering with the same issue to one degree or another.

All three were only straight enough when the truss rod was really quite tight. One owner had already over tightened the rod, the second was complaining of some uneven buzzing (the neck was a touch twisted) and the third had an almost new guitar which had too much relief in the neck when it came in, but with the truss rod already quite tight.

The problem is how slim the neck is, allied with the use of a heavier string and sometimes bottom heavy sets, and the modern age.

Angles and curves

A single part rod truss works by being placed in the neck in a curved state. When you tighten it, you're trying to shorten it, which forces it straighter and pulls the neck backwards. However, the less depth the neck has, then probably the less the initial curve in the channel. So the level of adjustment that each turn is capable of producing is slightly less. Once that rod is straight, it can't do anything - and that can also happen due to the fillet in the neck not being pushed in far enough during production (Mexican models apparently have a history of this, across the whole range). So there's nothing to force the resting state curved enough, adding to the problem of an already shallow neck.

Truss rods can stretch. It did happen to old guitars - early Teles suffered it for example, but in recent years it has seemed a more regular complaint. My guess is that it's probably because the supply of steel into the production process isn't the same as it was in the 1950's. Industrial processes required different properties in steel, and possibly that's made steel stronger for most uses, but decreased its tensile strength a little. It might also just be that cost cutting in production leads to lower spec steel being available for low tech products.

But Strings are the big issue. Here's the numbers:

A set of 9's - total pressure of 84.44lbs at A=440hz (25.5" Scale)

A set of 10's - 102.45 lbs

A set of 11's - 116.71 lbs.

That's 32.27 lbs difference between 9's and 11's - a whopping 38% extra pressure for 11's. As a guide, I'm just under 6' tall, and I'm about 170lbs. A lot of pressure goes on a guitar neck.

So it can become a bit of a perfect storm - heavy strings, not much wood to create stiffness, what is probably a low curve in the truss rod chamber, a rod probably more prone to over tensioning and the desire for low action. 

Now of course, wood alters from batch to batch, so a good number of these necks are quite happy with 12's at standard pitch - but if yours isn't, it's not game over.


The first is lighter strings. If your truss rod is fine now, but it's tight, using a lighter string will allow you to loosen back the truss rod, or at least prevent the need to tighten it further.

If you've got a body end adjustment with the cross head and you've run out of thread, the thread can be packed out to create a turn or two. Usually, if the neck is still concave without string pressure, this is allied with a heat straightening process.

If you've run out of thread and you have a modern Fender style captured nut headstock adjust rod, it's more difficult. To pack it, the walnut fillet has to come out. Sometimes a new neck is easier, especially if you have some twist too. If you're having a replacement neck made then I always suggest a true biflex rod (Rod and bar type) which has a flat profile channel - especially the gotoh/ steel channel ones because they add so much stiffness. A little more fretboard depth also really helps.

But the most important advice goes to Buyers:

Check the neck when you first pick it up. Is it quite straight, is the setup generally good? Then go ahead and check that the truss rod turns quite freely (if you can). If it's really tight, walk away. There's plenty of them out there, you'll always find another. It's just a fact that some people sell them when they go to a luthier for a setup and get told - "Sorry, the truss rod is already wound right up". Rather than pay to fix it, they just put lighter strings on for the sale, allowing less relief to be obvious.

If it's body end adjust, you can't check the rod tension so easily, and its got too much relief, walk away. There's enough of them that you'll find a good one.