Lefty Bass build: IB-6SL

I really liked the look of the IB-6SL, and why not have more strings on a bass?

I'm building this at the same time as the 3/4 build with my son in another thread. I'm very happy with this kit, everything appears to be very solid, the neck fits quite snug and the spalted veneer should look good with some stain on it.

There is just a tiny scratch on the fingerboard across the highest few frets. It won't matter too much but I think I would like to smooth it out if I can, but I'm not quite sure what to use here, since I know that fingerboards are pretty fragile.

https://i.imgur.com/1COPKhT.jpg
https://i.imgur.com/1BetMFy.jpg

I'm also not sure what that small half ellipse piece of plastic is for, it doesn't appear to go anywhere on the kit.

Hi Jarro, the spalted maple looks nice.

The larger half ellipse is the control cover for the back of the guitar, and the smaller one is the truss rod cover for the headstock.

Thanks, I just can't see how the small one fits over the truss rod ends (this one has two rods). I'll look again, maybe I'm missing something.

Oh yeah I can see it butts against the nut and I just put a screw through the hole.

Nice looking kit.
Always happy to see another lefty on the forum.
What is the weight of the kit like?

The shipping label says 5.4kg. It is pretty hefty, even the neck feels heavy.

Just make sure the pre-drilled neck mounting holes line up with the metal backing plate. I don't know why, but they often get them out of alignment with left-handed models.
Also, for some reason Pitbull wire the pots back to front on their Left Handed models, so for example, turning the volume pot clockwise reduces the volume. But they don't use proper antilog pots, so, apart from the unconventional operation, you basically get a magnified version of the problem you get using linear pots as volume controls!
I've never seen a commercially-built left-handed guitar wired like that; all the ones I've seen have the same wiring as the right-handed equivalents.

Thanks for the tips. This one doesn't come with a backing plate though, it has something like a big washer for each hole.
It also doesn't have any electronics soldered at all, so I can make sure it is done right.

I did a jm-1 last year and it had both those problems, I resoldered all three pots and one hole was off by not too much and it just squeezed in.

Best thing with the pots is to test them with a multimeter. Chances are they will be linear not log pots, but always best to check.
If you need log pots you can lefty pots from Realparts or GuitarTrade - search on Google for them. I have used their lefty pots on my builds. The CTS pots are pretty good.
There are commercially built guitars with pots incorrectly wired. I have a lefty Ibanez and a lefty classic vibe Squier which were wired back to front and with right hand knobs. I have also seen other lefties wired for right handers.
A multi meter and upgraded pots will always be the best solution.

Yep I've already done that. The tone pots are log and the volume linear, which matches the A and B written on the pots.
I'm happy with linear volume from my experience with my other guitar, if anything it just turns down a bit slowly, but seems to work fine.
Tone on the other hand basically does nothing until the last tenth which just makes it useless.

Quote:

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Originally Posted by jarro_2783

Yep I've already done that. The tone pots are log and the volume linear, which matches the A and B written on the pots.
I'm happy with linear volume from my experience with my other guitar, if anything it just turns down a bit slowly, but seems to work fine.
Tone on the other hand basically does nothing until the last tenth which just makes it useless.

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Good to hear that the kit came with some linear pots.
When I did the JM-1L kit they were all linear pots and I was happy with that one. They all work well.
Looking forward to seeing what you do with the kit.

This is starting to look pretty good.
https://i.ibb.co/CBP9xd0/bass-stained.jpg
https://i.ibb.co/8NvXhpK/head-small.jpg

For the fretboard scratch, I’d scrape the board between the frets with a single-sided razor blade. Scraping a fretboard is a standard method of removing dirt from the top layer of the board plus of removing small marks. You’re going with the grain, so you end up with a smooth finish.

I’d rub some lemon or mineral oul (chopping board oil) on the board afterwards.

Looking good Jarro.

The body is looking great with many layers of poly on and I got it shiny with car polish. I'll post more photos later, for now I was doing some electronics and have a question about the pick ups.

Does the spring go on top of the pickup, or under the pickup next to the body?

To ask another way, does the pickup go all the way into the cavity, or does it sit up like I am holding it in the photo?

https://i.ibb.co/R0tdV3q/20220522-151419.jpg

The screw is also quite long, if the head goes much past the top of the body the tip will come out the other side.

Quote:

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Originally Posted by jarro_2783

The body is looking great with many layers of poly on and I got it shiny with car polish. I'll post more photos later, for now I was doing some electronics and have a question about the pick ups.

Does the spring go on top of the pickup, or under the pickup next to the body?

To ask another way, does the pickup go all the way into the cavity, or does it sit up like I am holding it in the photo?

https://i.ibb.co/R0tdV3q/20220522-151419.jpg

The screw is also quite long, if the head goes much past the top of the body the tip will come out the other side.

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Hi Jarro,

the pup should sit out similar to your picture (though it will depend on the final height of the strings). The springs go between the body and the pup to push the pup away from the body (which allows for the adjustment distance from the strings). The screws should not come out the other side of the body.

Hopefully you have the correct size screws - but double check that they are quite a bit shorter than the body thickness!
My TB-4 kit had pups which worked the same way and the top of the screws are about 5 mm above the top of the body.

Quote:

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Does the spring go on top of the pickup, or under the pickup next to the body?

To ask another way, does the pickup go all the way into the cavity, or does it sit up like I am holding it in the photo?

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First, the springs go under the pickup, or you could say, between the pickup and the body. The spring is meant to push the pickup "up" toward the strings keeping a tension on it so it doesn't flop around.

The height of the pickup is going to be relative to the final height of the string action. The distance between the pickup and the string will be adjusted up or down to balance pickup volume and string tone. Typically with a normal string action, the pickups sit above the top of the body to varying degrees.

Quote:

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The screw is also quite long, if the head goes much past the top of the body the tip will come out the other side.

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You may need to just get shorter screws that are more appropriate to accommodate the pickup adjustment.

Thanks, I thought it was probably that way around, it makes sense that the spring holds up the pickup so that I can adjust the height. The screws are 35mm and the body is around 38 to 39. Given how high the fretboard is the pickups will probably sit up a bit and it should be fine.

It is pretty normal for the pickup to be supported by a block of neoprene foam rather than springs. It does provide a more sturdy support for the pickups. But the neoprene is not as springy as the spring, so you need to get a block the right size. But if you bought say a seymour Duncan soapbar, it would come with a foam block rather than springs.

Just a question about lining up the bridge. Since it's a bass, and string length needs to be longer, do I want it to sit at the scale length with the saddles fully forward, or do I go a bit further back than that?

You've got loads of saddle movement on that bridge. Set the saddles fully forward (end of the screw flush with the end of the saddle), then the top C string should sit slightly back from that when intonated and the rest then staggered backward from there. You still want to give yourself plenty of space to move the low B string saddle backwards as much as possible without over-squashing the spring.

One last thing, there is a tiny hole for the wire to earth the bridge that comes out under the bridge. But the bridge is covered in black paint which doesn't conduct electricity, and there isn't much room to solder the wire to the bridge without making the bridge stick up.

Should I scratch some paint off the bottom to solder it? Is there a good way to solder it so that the bridge still lies flat?.

Hi Jarro,

No need to solder the wire to the bridge. Just scratch (sand) some paint off the bottom of bridge near the hole, splay the ground wires out from the hole, and screw the bridge in place. The pressure creates a good connection.

Oh perfect, too easy.
I guess the strings don't end up grounded like with other guitars because the whole bridge is painted. I'm not sure how much that matters.

Any tips for wrapping the strings around the posts? I had a string pop off because the post is open, which I've never had in any other guitar.

If there’s no hole in the centre of the post to poke the string end down, then looking at pics of other IB bass kit builds, people often seem to put the first wrap above the string end going through the slot and the rest then below the string end.

I must admit it’s not a great tuner post design. The bottom of the slot is at the base of the curved section of the post, and not in the centre, so the tendency is for the string wraps to push the string up the post.

Oh yeah I see a hole, that's different to other guitars for sure.
Now I just have to fix the nut slots and get the action right, it's a bit hard to play right now.
I managed to get the welding tip cleaners to work for the highest three strings, but I can't find anything to improvise for the bigger strings. I might end up buying nut files.

I generally use the pointed tip of a needle file to cut the bigger nut slots on a bass nut, though I did rediscover an old nut file set that does bass strings as well as guitar ones, which makes things a bit easier.

I think I will give that a go first, thanks.
Would you cut the slots to the right relative height and sand the base down, or just cut the slots to the right height? I've read that the slots being too deep can be bad, but I'm not sure how much it matters.
Here is the almost finished product.
https://i.ibb.co/YWCvnwr/20220530-082201.jpg

For ease of fretting and minimal out of tuneness, you really want to get the strings sitting as close to the first fret as possible without buzzing. That distance will depend on your playing style. If you really dig in hard or pull at the strings, then you’ll need a bit more height than if you play lore gently and let the amp do the work.

Having the slots too high can result in notes sounding sharp on the first few frets as you need to apply more pressure to fret each string, increasing the string tension and making the note sharp, as well as making the bass harder to play.

But too low and you’ll get open strings buzzing on the first couple of frets, either occasionally (on loud notes) or all the time. Then it’s time to replace the nut.

The bass is looking really good.

Quote:

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Originally Posted by jarro_2783

I think I will give that a go first, thanks.
Would you cut the slots to the right relative height and sand the base down, or just cut the slots to the right height? I've read that the slots being too deep can be bad, but I'm not sure how much it matters.
Here is the almost finished product.

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Looking really good.
I read somewhere that the strings should sit with half inside the nut groove and half above. (cannot remember where I read this though!) I generally start with that positioning.
I also take into account how close the string is to the frets to avoid buzzing. If you need to cut down further into the nut you can always sand part of the top off if it is needed but that is personal preference and depends on how you play.
As Simon said the height you set the string depends on your playing style, so the best approach is to small steps when cutting down into the nut.

The half-in half-out nut slot thing is how McCreed dies it, and a few others. That’s about filing the top of the nut down after you’ve cut the slots l, so that it doesn't sit too high. Too high and the ends of the nut can catch on clothing and other items and break off if you’re unlucky. Just above half in is as low as you can go without risk of the strings popping out when you play. I normally file down until the top of the nut is level with the top of the strings and then round off all the edges. The two outer edges of the nut are the most vulnerable bits, especially as the ‘teeth’ are only half as wide as the central ‘teeth’. Too high and you get considerable leverage on the base of each ‘tooth’ if you catch the top of it, making it more likely to snap off.

Otherwise there’s no benefit to having a really low nut height above the bottom of the slots. The strings don’t touch more of the nut or anything like that. The more you file/sand towards the half-in look, the more you risk filing down too far; so mark a line to sand to. Don’t do a half in/out nut by eye or you may well need to fit a new nut! On a guitar nut, if you bend the strings a lot, you may need slightly higher than half the string height as a minimum, to stop the strings being pushed out of the slots as you bend. Partly down to your string bending technique. Whilst you may bend bass strings slightly, you won’t do it to the same degree and you’ll struggle to bend the strings near the nut, where the risk of popping out is greatest.

I finally got to finishing this. If I ever do a bass nut again I think I will buy the right tools.

One thing I noticed is that the tuners are twisting a bit. Maple seems quite soft and one tiny screw is probably not enough to hold it. I guess I need to buy better tuners with four screws if I want that to stay better.
https://i.ibb.co/fr5dw59/20220622-181538.jpg

They shouldn't twist. This type of tuner design is pretty much the standard for 'modern' tuners. The screw-down nuts should do 99% of the holding. So make sure they are tight, and not just loosely done up. When tight enough, the tuners shouldn't rotate even without the anti-rotation screw fitted.

I always fit the screws after I've tightened the nuts up, and drill the pilot holes in situ.

It may be that the headstock is too thin to allow the nuts to be done up fully, in which case you either need to thicken the headstock (can be done but a PITA), or cut down the length of the screw threads so that the nuts can be done up tightly (my choice). Stick the end couple of mm of the thread in a vice (the bit you are removing), and cut through with a hacksaw. 3 or 4 mm should do it, though double check by testing the length of thread needed to achieve a decent overlap first by removing a tuner and measuring against the side of the headstock.

Then smooth off the rough thread end with a file so that it

And maple isn't a soft wood. By far about the hardest wood normally used in guitar construction and you certainly need to drill decent pilot holes in it to prevent screw heads from stripping or breaking off.

Ok problem solved. I think I was afraid to over tighten, and there is a bit of wiggle room with the various holes. So it was all just too loose. I loosened off the strings, lined it all up and tightened and they are staying put now.
You're right about maple now that I think about it. The neck holes were the hardest to drill out of all the drilling I had to do.
Thanks for all the help to everyone. It even sounds pretty good on the kit strings, but I look forward to trying some Ernie balls soon.

Good news. I always tighten the nuts up each time I change strings on my guitars, as they do become loose with vibration. Worth checking them every 6 months if you tend not to change bass strings that often.

The kit strings are awful. Almost always low output, quite dead sounding and have been known to sound pretty uneven from string to string. Only really good for an initial set-up. If it sounds good with those, it should sound a lot better with EBs on.

Can someone please decode this capacitor value for me? I'm trying to work out if they gave me the right ones because the tone pots don't seem to do much.
https://i.ibb.co/HX4GfXn/20220624-180545.jpg

Just Google 6n8j. 6.8nF capacitor. Normal values are 0.022uF between 0.047uF, (22nF or 47nF). I tend to use 15nF caps as I don't like too muddy a sound, but 6.8nF is really small. Not surprising you aren't hearing much effect, especially if you are using the kit linear pot for tone. (nF= nanofarrads, uF = microfarrads).

The smaller the capacitor value, the higher the low-pass frequency 'knee' value is, so the less treble and mids get removed.

With bright single coils, 0.047uF is the standard factory value, and for duller humbuckers, 0.022uF is the typical capacitor value. With quite thick sounding humbuckers, 0.022uF is probably a good bet.

Ah that was a J, I thought it was a T. I had a suspicion it was 6.8nF, but it seemed low since 0.047uF and 0.022uF were the values I was seeing. So I thought there was some magic code I was missing.

They actually gave me 3 log pots in the kit, so I used two of them for tone. That definitely explains why nothing happens. I'll try getting 0.022uF next time I can get to Jaycar.

You should be hearing something happening, but probably not a lot.