Some people complain about the Jaguar from a players point of view. Common complaints are listed below.
"THE PICKUPS SUCK! THEY'RE TOO BRIGHT AND FEEDBACK ALL THE TIME!! LET'S ROUTE FOR HUMBUCKERS!!"
The pickups don't suck. They are virtually identical to Fender Stratocaster pickups. The only difference being that they have shielding claws surrounding them. These shielding claws do not really affect the sound, they are simply meant to shield the pickup from interference. Stratocasters do come with 250k pots as stock, though. Jaguars and Jazzmasters come with 1meg pots on the lead control circuit. This makes them brighter and more trebley. Turn the tone dial down if you want to have the equivelent to a 250k pot that is turned all the way up (in fact, a good idea is to turn the tone pot all the way down, then work your way up, as oppose to the other way around). You can also use the 'rhythm' circuit by flicking the switch on the upper horn control plate upwards. This will switch to the neck pickup only and will use 50k pots, which will take all the brightness out of your tone (infact, a lot of people don't like using this, as they say it makes the tone "too muffled"). Using the bridge pickup on its own can be very trebley and harsh. Using the neck pickup will provide a more balanced and bassier tone. Though both pickups must be switched on to achieve 60 cycle hum cancelling effect. The pickups come wired up in parallel as stock. A very simple modification is to wire them up in series. This makes the two single coils combine into a displaced humbucker. This mod takes the place of the bass cut switch, and pickups can then be put either in parallel or in series by flicking this switch. If you want to put humbuckers in a Jaguar, there is no need to route for full size ones. There are plenty of single coil sized humbuckers out there that sound the same.
Feedback can happen to any pickup at a high enough volume. It may be that you are using too much gain. Again, ease back on the tone control, especially if you're using the bridge pickup. Japanese Jaguar pickups are not wax potted. This is a kind of wax insulation which can stop microphonic feedback. It can be relatively inexpensive to get a guitar tech to wax pot your pickups.
"THE SHORT SCALE AND 7.25" RADIUS SUCKS!!"
The scale doesn't suck. The Jaguar scale is 24" from saddle to nut. The Stratocaster scale is 25.5" from saddle to nut. This is only about 5% difference in scale. All Gibson guitars, Les Pauls etc, are 24.75". That's only 3 quarters of an inch difference between the Jaguar and the Les Paul. Far too often is the Jaguar referred to (and dismissed) as a "short scale" guitar. When in fact it is more of a medium scale. And as has been mentioned, not dissimilar to the standard Gibson scale. There are also smaller scales than 24" used for guitars as well. For example, the 22.5" scale necks used on 'student' Mustangs, Musicmasters and Duo-Sonics etc.
The fretboard radius is curved to 7.25" on a Jaguar, the same as alot of other Fender guitars. Some people complain about "choking off" on these radius. A problem which can always be solved by raising the action by a very small amount. If people are insistent on having the action so low, in combination with bending 8's two whole notes, then nothing can stop choking off on a 7.25" radius. A Japanese Jaguar special has a 9.5" radius fretboard.
"THE TUNERS SUCK!!"
The tuners don't suck. The F-keys, used on American Jaguars from '65 to discontinuation in '75, have a few complaints. But whether or not this is because they are simply worn out, is unclear. All Kluson Deluxe and Kluson Gotoh copies (Gotoh's being used on most all Fender American Vintage and Custom Shop guitars) are fine. As are the Kluson Ping copies that are used on All Japanese Reissue Fender guitars. As has already been said, the tuners do not need replacing unless the gears are worn out. The tuners hold pitch fine, but are not as smooth to tune up as Schaller/Groover style sealed units, because of the ratio difference. This does not mean that the tuner will not hold pitch just as well as any other tuner though.
Keep the gears lubricated. Grease should be injected through the small hole on the back of the gear housing. Use a tube of grease. Make sure it is pressed level and firm against the flat surface over the hole with both hands, then get someone else to squeeze the tube if possible.
"THE BRIDGE SUCKS!!!!"
Ok, the bridge can suck. IF it isn't set up properly. Part of the problem with the bridge is not that it simply "sucks", but that it can be so complicated and difficult if you don't know the intricacies of it. The reason why it is so difficult to set up is because it incorperates two, if not three, different bridges. This gives the bridge many variables (ie the height of the assey, the height of the saddles, the play/free movement of the swaying bridge and the bearing they all have on one another). For instance, the saddles themselves are in essence not really any different from the way that Telecaster or Stratocaster saddles work. The only difference is that Strat or Tele saddles don't sit on a raisable assey. They simply sit on a steel plate that is fixed to the body and never moves. Another point to make is that the bridge assey isn't that far removed from a tune-o-matic bridge. The only difference there is that the saddles on a tune-o-matic are fixed in place, in terms of sideways/up and down movement, to the assey. So what we actually have is a kind of hyrbid bridge, which is one of the most adjustable out there. This also makes it the most difficult to set up.
Some people claim to knock the strings off Jaguar saddle grooves. An easy solution, for those that need slightly wider grooves on the saddles, is to put Fender Mustang saddles on the bridge. The Jaguar and the Mustang share the same bridge assey. But the Mustang saddles have a single groove that is slightly wider. They also don't have grub screws. Instead, there are 3 different sizes of saddle, placed in different places along the assey according to their height. This gives a fixed radius to the Mustang saddles. However, one problem with the Japanese/aftermarket Mustang saddles, is that they are not as wide as the American Mustang saddles were. This means there is a gap in between each one. Allowing them to slide from side to side on the assey somewhat. This shouldn't present a major problem, but is a minor annoyance. It is also a design flaw that has been passed down to the Graph-Tech "Stringsaver" and "TUSQ" saddles, which are intended for Jazzmaster and Jaguar bridge asseys. Graph-Tech obviously designed their saddles after Japanese Mustang saddles. They have been contacted and told, but no change seems likely, now that the current specification stands in place. The same is true with Fender Japan's Mustang saddles, except the '65 reissue specials.
"THE TREMOLO SUCKS! IT MAKES THE GUITAR GO OUT OF TUNE!!"
The tremolo doesn't suck. Use of the tremolo will not make the guitar go out of tune anymore than other 'vintage' styles of tremolo. If you don't want the Jaguar to be a tremolo guitar, you can simply lock it by turning the adjustment screw round clockwise until it bites. After this, the Jaguar will be completely hard tail. The angle of the strings that go to the trem isn't really much different than the angle on a lot of Gretsch and other jazz guitars. But if you wanted the angle to be less obtuse, you could use a Whizzo buzz stop. The Jaguar does stay in tune well with trem use because of the swaying bridge. It is the same sort of principle as the Schaller roller bridge, in respect of not dragging the strings through the saddle grooves.
You might like to buy a completely new set of strings. New Jaguars usually come with roundwound 10's on them, as stock. String gauges such as 8's and 9's are not generally suited to Jaguars, or other guitars with the same sort of angle going from bridge to tailpiece (though feel free to experiment, as different peoples playing style will suit various gauges). 11's are pretty good, as are 12's or even 13's! But 11's will be best for ease of playing/bending. If you're going to be using very thick plectrums and hitting the strings very hard, thicker strings are most certainly advised. The G and thick E strings can be the ones that will most likely buzz against the frets, should you give them a good twang. Heavy strummers could try at least 0.018"+ for the G and 0.050"+ for the thick E. With D'addario "medium top/heavy bottom" being a handy set in these scenarios.
Quite a lot of people use flatwounds on Jaguars and Jazzmasters ("tapewounds" or "ribbon wounds", as you may also hear them called). Most companies make sets of them. The Fender flatwounds are arguably the best quality, as the ribbon join is not visible. However they are quite difficult to get hold of. So perhaps the more popular flatwounds are D'addario "Chromes". The ribbon is made of stainless steel, not nickel plated like normal roundwound strings are. These D'addario flatwounds have 4 wound strings (E, A, D and G). The thinner B and E strings are plain steel. Other flatwound sets, like the Fender Flatwounds, have 3 plain and 3 wound (plain G). Flatwounds also have the benefit of lasting a lot longer than roundwounds, and can be cleaned with Autosol back to new condition very easily. They are also very forgiving on your fingertips. Criticisms of flatwounds would be that they don't ring as much as roundwounds and have more of a thudding percusive tone to them.
The best way to set up the bridge is to apply grease to all the threads including grub screws and intonation screws. The bridge assey height screws are, in my opinion, usually the screws that can buzz in some situations. If you stretch wrap cling film several times around the threads, or possibly use thread lock on them, there will be no play. This should cure bridge buzz, if it occurs. It's also better to have the screws threaded further into the posts, so that they have more purchase and cannot rattle as much. Which is handy, as we'll be raising the saddles up high anyway (more on this further down the page). With the saddles higher, the assey will be lowered and screws threaded further in.
There should be 3 different lengths of spring, long, medium and short. When the bridge gets intonated properly, it ends up roughly like this:
With plain G string:
With wound G string:
So you can figure out for yourself which spring will suit each saddle best for either situation, if you are going to disassemble the bridge.
For individual saddle height adjustment, one method can involve raising the saddles up high, so that they can be almost locked in place. The G and D saddles will be the highest. You can raise them up until the screws become difficult to turn. But you must avoid the grub screws coming very near to tapping out of the bottom of the saddle. You can adjust the outer saddles for a guesstimate of the fretboard radius. The thick E saddle and the G saddle intonation screws may need to be hack sawed shorter (in an ordinary plain G string situation). Because those two saddles end up the furthest back, you'll find that if they are too high, the intonation screw will 'fret' the string off. On a Japanese Jaguar bridge, you may want to hack saw more of the intonation screws shorter, because they are all very long. If you really want to lock the saddles well, you may even need to shorten more of the intonation screws, even on American jaguars that have shorter screws to begin with.
You should have roughly intonated before the raising of saddles. In fact, you should put the strings on, and be doing a little bit of each until maximum height and precise intonation are achieved. Although it can be difficult to obtain perfection sometimes, it's all about how you want things. And being satisfied that your setup is good enough for you in a playing situation.
I would have the saddles level with the assey on which they sit, so that the sides have a good contact with eachother. And it can be quite easy to abide by a steel rule when raising the saddles so that there is a distance of 2-3mm between the top of the 17th fret and the bottom of the open strings. But if you want to precisely set up the bridge for the 'cambered' effect, which allows for greater string radius accuracy when utilizing the adjustable string spacing that Jaguar saddles have, then you can make a contoured radius gauge out of strips of card and pritstick style glue. The strips should be about 1cm wide and 6cm long. Paste some glue on one side of a strip and then apply another strip on top of it. Keep applying other strips on top until the gauge is over several mm thick. Make sure the strips are directly on top of one another and squeeze them together so that it is flat with no excess glue inbetween the strips. Place the gauge after the last fret on your fretboard and contour it to the cambre of the board. Because the glue has not set yet, if you leave the gauge in place with the strings forcing it down, then when it has dried it will be contoured with the fretboard. And you can then use the gauge as a guide to adjusting the individual saddles to the 7.25" radius of the fretboard.
Take the allen key and lower the entire bridge assey so that it is pretty low, but level either side. Make sure that all of the open strings are muted by the gauge. If they are not, then the gauge may not be thick enough and you will have to apply extra strips. Tune all the strings up slightly sharper than they would normally be, taking care not snap any of them. Carefully pick the thin E string up vertically out of its groove and place it on either of the grooves nearest the edge of the saddle. Press the gauge down onto the fretboard either side of the string and pluck it very gently. It should be muted. Take the string up out of the far groove and place it back in a more central groove so that you can get the allen key into the grub screw. Turn the grub screw clockwise a fraction to raise it, then put the E string back in the same groove at the far end of the saddle again and pluck it gently. Repeat this process until the string can just about ring and so that there is a hairs width between the string and the gauge. Then take the string and put it on the opposite far side of the saddle and do the same. Then do the same again on all the other saddles. When you've done all the saddles, you can adjust the entire bridge assey for your preferred action.
Some people like to wrap the bridge posts with insulation tape, just enough so that the posts fit flush with the bushings in which they sit. This means the bridge cannot rock. You probably won't be able to do this in conjunction with a Jaguar that has a mute fitted though (unless you drilled bigger post holes into the mute plate).
Loosen the strings enough so that you can take the bridge out. After taking the bridge out, make sure the cylinder and spring are in the small route. Place the mute plate over the top and screw in the 2 self tapping screws until they are all the way in and the mute cannot be moved at all (no need to make them too tight, or you may strip the threads, just nip them up). We now know that the plate is level on either side. Turn both screws anti-clockwise 3 quarters of a turn. This may be enough for the mute to be flipped. If it isn't, then turn both screws more. But make sure you turn them equally (ie, if you turn one of them 1/8th of the way round, do the same to the other one) so that you know the mute is still level either side.
Once the mute is able to be flipped in a proper manner, put the bridge back in and tighten the strings up so that they are fairly tight and can ring (don't bother tuning in to pitch). Level the bridge to the centre position and flip the mute into the on position. If it mutes all the open (unfretted) strings then that would be job done. But in most cases it should fall short and the strings will either not be muted at all, or some of them (probably the D string) will not be muted properly and will more likely buzz against the mute pad somewhat. When this happens, we start from the beginning again. Loosen the strings again and take the bridge out. Turn both mute screws anti-clockwise a small fraction (say, an eighth of a turn. Less, if you want to be more accurate). Put the bridge back in, tighten strings up and flip the mute. Repeat these steps until the pad mutes all the open strings properly.
If you have the strings higher at the bass side than at the treble side, then you may like to have the mute slightly higher at that same side. So you can turn the bass side mute screw a fraction more than the treble side mute screw in these scenarios.
This mute setup guide best describes stock mutes that have been taken off or need readjusting. If some of your mute parts are home made, then you may have to do things like shim the neck, raise the bridge and lower the saddles in various combinations.
Relevant excerpts taken from the general Fender manual: