Customised Fender USA “Original ’60’s” Jaguar – Setup tweaks after new neck installation

Having carefully set the CAR Jaguar up with one neck – I now need to check that the same perameters apply for the new neck. With luck – the instrument is already somewhere quite close to where it needs to be, but it’s possible that the vital geometry, and various nut/bridge/strings/neck relationships may have subtly changed.

Fender Jaguar Setup – The new neck means a few tweaks may be required

Although the previous Musikraft custom neck had been prepared to match many standard Fender vintage measurements – I can’t help but notice that the new neck, although itself a “65 re-issue”, seems to sit a little lower at the heel. Whears the Musikraft neck didn’t seem to need a shim – the Fender neck seems a little “level”. Consequently, the action, after the straight swap, is stiffer, and visually – the strings seem to diverge from the line of the fingerboard slightly, further up the neck. With the mute installed – there’s not much I can do to lower the bridge, without fouling the mute plate. Although the Fender “Original 60’s” body apparently is engineered with a sloped neck pocket – it looks like I might have to give the neck a bit of a helping hand, with a shim.

Providing the ideal string alignment

I recently got asked what I thought about shimming the Jaguar neck pocket – (just as I happened to be adressing the same issues with this Jag). The main thing with the Jaguar, is getting the right neck angle in relation to the plane of the body. Take a look at a Les Paul – the way the neck sort of falls away, with the headstock dropping back – Leo Fender’s original offset concepts were supposed to be based around that same, “archtop” geometry. With a tall bridge, (and the Jaguar bridge is supposed to stand taller to provide more downforce – not just to clear that mute), you somehow need the neck to rotate back slightly, pivoting around the point where the neck meets the neck pocket. On Fenders, that’s usually around the 17th fret. The ideal situation then allows the strings to run roughly parallel with the whole length of the fingerboard – rather than diverging, (as in this case). The ideal alignment then enables the string action to be fine-tuned and set, by simply lowering or raising the bridge a minimal amount. The trick is getting that neck/body angle in just the right sort of range first.

With bolt-on necks, that’s always been done with a shim – The original Jaguars all came with a simple slip of pickup bobbin fibre wedged in the pocket, under the heel of the neck. So – shimming, (no matter how simple or crude), is the “authentic” thing to do.… The question is – how thick to make the shim here? When shimming the neck – the first thing I like to check, is that the neck relief is flat to begin with. This is a brand new neck, and Fender necks are usually shipped with the truss rod nut slack, or “neutral”. Once the strings are tensioned – this should create a slight forward bow to the fingerboard, so I like to tighten the truss rod, just a quarter of a turn or so, to compensate. This provides a little extra tension and “backbow”, which counteracts the pull of the strings. Since I’m using a slightly heavier set of roundwound 11’s here – it might amount to no more than a half a turn really, but truss rods shouldn’t ever really need to be cranked much anyway. The only way to check what’s needed, is to slip the neck off, tighten the truss rod slightly, (only ever make small adjustments at a time – and ideally let the neck settle for a while before re-assessing), and then retune. When temporarily removing the strings, I tape the strings together at the nut so I can stop them tangling – and after adjusting and re-fitting the neck, I re-install the coiled string ends around their capstans. Neck relief is measured with a feeler gauge at the 8th fret, once the strings are brought back up to tune. The strings are capo’d at the first fret, and are fretted at the top fret whilst they’re measured, and this allows the deflection at the mid-point to be measured accurately. This neck, as supplied, had a “natural” relief somewhat over 0.015″ – wheras Fender recommend 0.012″. A full half turn of the truss rod nut was eventually required to get the strings down to the ideal level.

Once the desired neck relief has been dialled in, and the guitar has been left for a day or so with the neck under tension – I check the relief one last time. There hasn’t been any noticeable movement due to settlement – so I’m calling the neck “flat”, and I can now asses what sort of thickness of shim I need. But the neck will have to come off at least one more time to install it, and it may take a little trial and error.

Looking at my other Jaguar builds – the situation seems to vary on just about every offset I’ve put together. The easiest way to find out what’s required and deal with it, is to get hold of a few StewMac shaped neck shim wedges. They do a mixed pack of three – 0.25, 0.5 and 0.75 degrees – all shaped to standard Fender neck pocket dimensions. Here, I’m trying with an 0.5, first. The shim needs to be slightly modified to sit correctly in the pocket – so a little shaping is carried out to the curved “thick end”, and to the side where the pocket opens onto the neck cut-out. Modifications are easy with a sharp scalpel blade. With the shim fitted – the neck is re-installed, the strings brought up to tension once more. I can now visually check the line of the strings against the top of the frets and the straight fingerboard.

Shim installed. Checking the string and neck alignment

The 0.5, in this case, is just about spot on. The full setup hasn’t been done yet – but already I can feel a significant improvement on the handling of the guitar, with just that slight change of angle. The action feels slightly “lighter”, and where there was, previously, a little bit of random high fret buzz here and there – that has now been completely eliminated. No doubt it helps that the bridge has already been set to a workable height, and that the fingerboard is pretty flat. Now, I’m confident that I can work on the nut, and then adjust the bridge slightly to achieve a good overall action. Before continuing – I slacken each of the neck bolts off by a quarter of a turn. This allows the strings to pull the heel of the neck in tight against the pocket. There’s usually a satisfying “clunk” as the neck gets pulled into place. After a final check that the neck/body alignment is good – the neck bolts are tightened up to pinch tight.

The StewMac shim method is the easiest way I’ve found to solve the neck angle problem, and having a range to choose from covers most bases, (without having to resort to mathematics). If the 0.5 shim hadn’t have worked – no doubt one of the others would. I’ve even stacked shims in the past, to provide extra lift. My only real problem with the StewMac shims is the cost. (Especially as I’m in the UK, and they usually have to be imported). But the pre-cut and shaped shims make it so much easier, and they’re also supposed to be much more dependable in the long term. You might well be able to get the same results with a few thicknesses of sliced-up business card, but the shaped shims offer more support and “wood to wood contact” across the whole neck pocket area. That, in turn, is supposed to provide maximum vibration transfer between neck and body. It seems, overall, to be a considered, solid solution. I suppose you get what you pay for.

Tailoring the pre-slotted nut

So, on with the setup. The nut is already pre-slotted, but the action still feels a bit stiff in open positions. I measure the first fret height at about 0.041″, and calculate each individual slot height above the fingerboard. These slot heights need to accommodate a clearance over the first fret which is sufficient to avoid a vibrating string fouling on the top of the fret, as it passes over. For a 7.25″ radius curved Jaguar neck like this – Fender recommend 0.020″ on the bass side, and 0.018″ on the treble. By adding these values onto the height of the first fret – I can work out a set of values to apply to the string slots at the nut. For this neck, they are, (Low to high):

0.067″, 0.067″, 0.066″, 0.066″, 0.065″, 0.065″

The slots are cut to the required depth with a StewMac “SafeSlot”, and a set of precision-sized Gotoh nut slot files. The individual slots are then cleaned out and polished with some fine emery paper. The slots are all cut so that they fall naturally towards the pegboard, and slightly flare at the headstock side. A slot full of crud, or a badly shaped slot, will often reveal itself with a slight buzzing, ringing or even choking to an open string note. A polished, well cut nut is always a vital step towards great tone.

Checking the tuning and intonation.

Next, I need to set the string heights for an easy action. The setup for the previous neck means that the bridge is already at a workable height, and requires only minimal height adjustment to provide the ideal string clearances at the 17th fret. Here – that’s 1.8mm on the bass side, and 1.6mm on the treble. The adjustments are made by turning just the two screws either side of the Staytrem bridge. The saddle radii are already pre-set, and require no additional adjustment. Once the bridge is set – I can make final intonation adjustments using a chromatic tuner. These are set via the intonation screws – one per saddle – which I’ve positioned here, on the side facing the tremolo plate. (Sometimes the bridge is placed with the intonation screws placed on the pickup side – but any easy adjustment is impossible with the Jaguar mute plate in place).

Jaguar tremolo lock button adjustment

The tuning is checked once more – across the neck using string harmonics, and once again with the chromatic tuner. Once tuning has been settled – the lock button “memory” is set. First, the lock button is set to the “off” position, (closest to the pickups). The spring tension is then adjusted via the tensioning screw – until the lock button, when engaged – just matches the same height of the internal “ledge” of the pivot plate. You can feel it better than I can explain it – but critically, the tremolo plate hits a little shelf, and is prevented from moving upwards beyond the set point. This can be useful if you break a string mid-performance. Rather than having to re-tune all of the other strings, (which will now have been pulled sharp, due to the tremolo spring overcoming the force exerted by the remaining strings), simply press the tremolo down, and slide the lock button over to the “engaged” position. The tremolo will now return to the pre-set “memory” point – which just so happens to be the point where the strings are exactly in tune. The same point I have just “locked into memory”. Whenever the lock button is engaged – the tremolo won’t pull sharp at all, so the device is sometimes ignored by players, who want to use the tremolo to pull sharp and flat, (or who frankly do not understand the purpose of the lock in the first place). However – you can still dive bomb with the lock engaged, and you don’t even have to actually use the thing until you suffer that dreaded broken string. Having the function set up correctly beforehand, is infinately preferable to having to re-string or re-tune, mid-performance. (It also serves as a useful device to quickly re-tune – but if any changes are made to the setup in general – the “memory” point should be adjusted after any changes are completed).

Fender Jaguar “Original 60’s”, with Creamery “Alt-88” pickups and “Johnny Marr”, 4-way switching

With only slight, final adustments required to the pickup heights – the guitar is finally set to a pretty stock, Fender action which feels sweet and responsive. The Creamery pickups have an additional range over standard Jag pickups, and the 4-way switching offers an extra, (and unusual for Jags), humbucker-like, bridge/neck combination. Paired with the more traditional looks – this is a custom combination – some new and some old features and, I think, the best result I’ve had so far, in putting my own offsets together.

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