JB-4L (Jazz Bass Left Handed)

[Keith Walters]

I see colin2121 is making the exact same Left Handed Jazz Bass as I am.
It's a bit late now, but this is how I set up the bridge position.
I used some cotton kitchen twine, (which is normally used for tie-ing up roasts and the like), because it doesn't stretch.
I just used Blu-Tak to secure two lengths of the twine behind the nut:



I marked the position of the 12th fret with a Texta pen, and then doubled the twine back and marked it where it passes through the nut. (It's better if you can get someone to help with this). That way the first mark should be at exactly half the scale length, and the second should be twice that, that is, the actual required scale length:



I added some weights to the other ends of the twine so it hangs over the end of the body, keeping the twine taut:



Then it's a simple matter of dropping the lengths of twine into the relevant slots on the bridge and moving the bridge around until the twine lines up best with the outermost pickups, and the Texta marks line up with the centred adjustable bridge saddles. I'd recommend you just drill two pilot holes at first to make sure the bridge hasn't moved, and re-check the alignment before you put the rest in.



By the way, I'm writing an article for Silicon Chip magazine about my experiences with this project, which is why I haven't touched the headstock, because, you know, Fender and their friends get a bit tetchy about what they see as their copyrighted designs!
That's actually another reason I went for the Natural Wax finish; if you do any subsequent modifications to the woodwork, it's really easy to re-finish it, which is not the case with lacquered finishes.

[Simon Barden]

I like your string initiative, but I'd really suggest that you move the bridge back a bit. The 12th fret to the saddle distance is always going to be slightly longer than the nut to 12th fret distance. The G string will have it's saddle furthest forward, and the D, A and E saddles should respectively each sit a bit further back. Wind the saddles forwards until you've still got about 5mm of thread showing, and then repeat your positioning exercise.

As it stands, you may not have enough space to wind the E string back far enough for correct intonation - especially as the spring behind the saddle only compresses so far before you can't move the saddle any further. It looks like you've already drilled some holes - so you may as well try and string it and set up the intonation, but I fear you will struggle to do so.

[Keith Walters]

I'll see what happens. If I have to move it back I can just put a couple of screws in the old holes, or fit a couple of blue LEDs or something to announce it's on Bluetooth. I can even run the wires through the bridge earthing hole.
Alternatively, if I can't wind the saddle back far enough because the spring won't compress any more, I can always put on a shorter spring!

[Keith Walters]

Hi Colin,
I have some of the Scandinavian Oil as well, but nothing beats the Gilly Stephenson Cabinet Wax. You can get it in Bunnings, and it's not expensive. Also the tin I have is about 8 years old and it's still OK. If you scratch your guitar you can fix it in no time with that stuff.

I'll probably try putting the strings on tomorrow.
I'm not convinced intonation is so critical on a Bass, because you don't normally play it that far down the neck.
It's much more important on a 6-string, but I'd never try to build one of those; I've left that to the experts!

[wazkelly]

Hi Keith, don't underestimate the importance of intonation on a Bass as a lot of people think it only matters higher up but if the string length is wrong to begin with the out of tune phenomena kicks in much sooner and quite often before reaching the 12th fret.

Best thing is as Simon said and to have at least 5mm thread in front of the G string saddle where it should then measure 34" from the inner side of the nut.

Cheers, Waz

[Andy40]

Hi Keith, you go to Bunnings a lot...you know its customary to take a selfie? lol

are you going to eventually make the bass a string through or keep it top loaded?

[Keith Walters]

Hi Keith, you go to Bunnings a lot...you know its customary to take a selfie?
I work next door to Bunnings, so the temptation is always there...

are you going to eventually make the bass a string through or keep it top loaded?
Sorry, I've got no idea what that means.

[Keith Walters]

Hi Keith, don't underestimate the importance of intonation on a Bass as a lot of people think it only matters higher up but if the string length is wrong to begin with the out of tune phenomena kicks in much sooner and quite often before reaching the 12th fret.

Best thing is as Simon said and to have at least 5mm thread in front of the G string saddle where it should then measure 34" from the inner side of the nut.

Cheers, Waz

I'm going to make it as good as possible, even if I have to move the bridge. However I suspect there's a limit to how good a $199 (including postage) kit is going to get....

[wazkelly]

I'm going to make it as good as possible, even if I have to move the bridge. However I suspect there's a limit to how good a $199 (including postage) kit is going to get....

Hi Keith, The kits are quite good, better than a lot of $500 store bought axes, and the only low grade items are the tuners. Stock pickups are good enough and so is the bridge if positioned correctly and using light gauge strings.

[Keith Walters]

Hi Keith
One thing I discovered when I put the kit together, the output jack was not tight. I had to unscrew the knob plate and tighten it after the first try into an amp. Might be worth a quick check before you screw the plate down.
And the intonation is important. Took me forever to get it right, but my hearing is not great.

Don't you normally use a guitar tuner?
I noticed the output socket is a bit ordinary-looking. Since I plan to add on-board electronics at some point I'll be replacing it with a stereo socket to do the battery switching. Cutting the hole for a mini-USB charging socket will be a challenge!