saw this on TGP. figured it was relevant to the discussions around here.
Jazzmasters are among the coolest looking guitars ever made. Unfortunately, the original design had many weaknesses that made them a very unstable and almost un-useable instrument.
We discontinued Jazzmasters several years ago as we just felt that without some re-tooling that they are just not something we want to make. Our goal has always been to make guitars that are as transparent as possible. Guitars that have faults and quirks that interrupt the creative flow are not good and neither is a guitar that cannot be the only guitar you take to a gig with confidence.
We feel we have finally achieved a great Jazzmaster.
Some history goes a long way in explaining some of the issues. This guitar was intended for Jazz guitarists, hence the name. The design of the bridge, tailpiece and electronics make way more sense from this perspective. The bridge worked well for gentle playing with the occasional bit of subtle vibrato.
The bridge was meant to rock back and forth in the cups so when vibrato tailpiece was used the strings stay in place in the bridge saddles and the whole bridge would move. For anyone that rests their hand on the bridge for palm muting or extra control, this proves to be a bad design as you can move tuning easily. Guitar feels less solid and sustain is hampered by the overall lack of connection between strings and body as the bridge rests on two tiny pins. Works just fine for jazz player playing choppy rhythm or clean solos, but not for most players.
The strings will also pop out of the saddles if guitar is played with any great enthusiasm. This is a problem caused by three design issues which all lead to very little string tension over bridge and tailpiece. The strings are on a nearly flat angle, meeting the bridge. Then the angle after the bridge leading to the tailpiece is also very flat. Picture how the strings travel on a Les Paul and then compare to a Jazzmaster.
So the bottom line is you have very little string tension going over a very unstable bridge ending at top loading tailpiece.
So what we did is to first change the neck pocket and neck angle. This gives us a greatly improved starting angle. Now we can get the bridge itself much further off the body and still get the action low. Also, the angle after the bridge is going to be more severe. A big improvement in sustain and stability.
Next we use a much better designed bridge. A solid tune-o-matic type of roller bridge with normal posts. Now strings move easily over roller saddles on a fixed bridge that is solidly anchored. Tuning, sustain, stability are even further enhanced. Strings will not easily pop off the saddles and the bridge intonates much better as saddles have increased travel.
Next we are using the extra roller attachment on the tailpiece piece so the strings get even more tension and stability.
One of the other issues that we addressed is that though conventional wisdom says that the radius of the bridge and radius of the neck should be the same, this is not the case. Since the fingerboard is curved and bending strings on the high E and B push a string into an area that by its location is higher, the E and B strings will generally need to be set higher, with the E more so than the B. The G string when bent moves to an area equal to or even lower than the start point and D actually even more so which is why they have little problems with rattle or fret outs. This may sound complicated but grab a guitar and bend the high E somewhere above the 12th fret. As you bend it, it moves into the area normally between the B and G strings. Since the neck has a curve, your E string has much more possibility of fretting out unless your action is set to compensate. OK, great you say, but you never bend the low E or A strings so why do those strings also need to be higher? As it turns out since the lower strings have a larger arc of movement, flattening (or increasing the radius) of the bridge in relationship to the neck also helps with minimizing the fret rattle of the lower strings as the E and A are now also a bit higher. We settled on a neck radius of 12 and a bridge radius of 14. Yes, a Jazzmaster for a serious lead player.
Now we move on to the electronics. Once again, a bit of history helps. Leo Fender disliked midrange and enjoyed bass and treble frequencies. Someday I can share with you my theories about how this happened, but for this paper, just know that the wider the range of treble and bass, at Fender the happier they were. How many guitars have you played that the bridge pickups seems rather harsh, bright and underpowered while at the same time the neck pickup lacks clarity, is boomy and over powered. This is because most pickup sets use the same pickups for both positions. Or in some cases they may use different pickups as far as magnet strength and winding, but do not actually get a big enough difference between the two to yield a completely useable mix. Jazzmasters, like many guitars share virtually identical pickups in the neck and bridge. This is great on paper as you get the brightest sound out of the bridge and the bassiest sound out of the neck. Leo and most designers feel or felt that this gives the player the biggest palette of tones to choose from when it is actually the opposite. Les Pauls and 335s are great examples of this. If you set your amp so that the bridge pickup alone sounds great, if you go to the neck pickup it is almost always way too loud and bass heavy. If you go the other way and set your amp for the neck pickup and get it sounding great, the bridge will now sound shrill and weak. To deconstruct the guitar a bit, a pickup takes energy in the form of vibration and turns it into an electronic signal that gets amplified. Pick a string right next to the bridge and pick the same string at the end of the neck. There is a huge difference in volume and tone. This is because the closer you get to the end of the performing part of the string the less energy and vibration is present. Think about a jump rope and how little movement is going on at your hand versus the huge swings in the very middle. Guitar strings mimic this. Our approach has always been to address this problem with a very large difference in the magnetic strength, windings and power of the pickups in relationship to each other. So a simplified solution is to go underwound on the neck and overwound on the bridge. Not just a little bit, but in some guitars as much as 50% more on the bridge. On the Jazzmaster sets, we asked Jason Lollar (who is quite familiar with our approach) to come up with a great set of pickups for them. I think you will be really happy with them!
Switching layout on the original Jazzmaster was interesting but was not really useable. Once again the Fender design took into consideration the desire for treble and bass and hope for a great success in the Jazz world. This is even more obvious on the Jaguar, but that is another discussion. For those who either never figured out or never used a Jazzmaster, the idea was to be able to instantly switch to the neck pickup alone and on an independent vol/tone circuit. Halfway cool, but almost never used and unless you use the guitar regularly sometimes you find yourself struggling to get it set where you want it. Our wiring plan is to use the same layout, but the top switch acts as a circuit selector so you can use either or both pickups in either the lower master volume and tone or upper master volume and tone. Much easier and offers a better variety of uses.