DIY Ukulele Bass

Spending £400 on a Kala Ubass is a big commitment, and as a young adult I simply don't have the money to invest. This is a simple conversion as originally conceived by Olivergon on this. What you need: Donor guitar- can be 1/2 or 3/4 size as long as the scale length is correct. Ideally 20-21" but anything between 18-25" is okay. You will need to order the strings. Pahoehoe or thundergut strings- Pahoehoe do the 18-25" lengths, and these are what I used. Bass tuners- or you can widen the holes in the original tuners with a drill if they are similar to the tuners shown on mine Drill Brill bits- 1mm for pilot holes, and 5.5mm for the string holes, you'll need good HSS bits if your widening the pegs if thy are like mine, mine had some pretty hard brass that needed to be wasted. Needle/round files

Step 1: Order Strings

You'll need to get some short scale bass strings, whether they are Pahoehoe strings ( or Aquila Thundergut strings from EBay or Amazon. Order these first because you need them to sort out your nut and bridge setup.

Step 2: Prepping the Guitar

Remove the strings and the tuners, quite simply with a wire cutter and a screwdriver.

Step 3: Put on the Bass Tuners

Again, simply attach whatever bass tuners you've gone and bought. As long as they are stable it should be okay. I actually widened the holes in the original tuners with a drill to hold the string. This is risky, I broke 4 of the pegs when I was doing it.

Step 4: Measure Out the Indents for the Nut

You'll need to measure ye width if the strings, add them up. Add the space you want from each side and divide by three for the spacings. If you don't do this the 3rd and 4th string will be quite close together, which is not ideal.

Step 5: Drill the Holes in the Bridge

Again you'll need your measurements to ensure ideal spacing. Ideally you'll want holes of 5.5mm, but 5mm will do.

Step 6: Electronics (optional)

Order your bits- you'll need a guitar preamp thing as shown. Mark and cut your holes Drill a hole in your bridge for the piezo wire to feed through. Measure the height of the piezo piece and file/sand away as much off the bridge. Insert everything appropriately and connect them up, and then hopefully up can test it by tapping on the bridge.

Step 7: Attach the Strings

Use a washer and tie a knot in the end of the string. With pahoehoe strings they have a thing like a small washer so you need need to on these. Thread this up from inside your guitar. At the tuners, you may want to decide whether the string wraps from the outside or the inside for the best string alignment. You'll have to to stretch out the strings other wise they'll end up jumping over the top of the tuning peg. What I did was pull it so it was close to the string note. And then, with some effort, force it into the tuner. (For the 1st and 2nd string, no need for the classical tuners)



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    9 Discussions


    3 years ago

    I have wanted to make a bass ukulele for some time, if I want to make it from scratch would I just get instructions for a normal uke and upsize?


    4 years ago on Introduction

    Great tutorial! just wondering, what preamp stuff did you use and where did you get it from? cheers :)

    3 replies

    Reply 4 years ago on Introduction

    Hi Adam

    I think was a cheap as thing from eBay. It was actually a guitar pickup and amp which is definitely not what I recommend

    It would be best to get an Artec bass pickup and preamp kit, something similar is available on Gear 4 Music.

    The problem I had with my bass ukulele is that the strings were not in the correct position over the pickup. If you're attempting this indestructable then do make sure you line your strings up properly.

    Kind regards

    Had this sad, old, little Santa Rosa K55 (1/2 size) lying around, which I inherited from my nephew, who learned on it some 20 years ago and has since moved on to bigger and better things. Completed the conversion earlier today (about 3 hours of work at relaxed pace in total) pretty much exactly as per this Instructable, except that I did not even bother to attempt to use the original tuning pegs.

    Installed a UK-2000 from Amazon:

    Just now discovered this suspiciously similar looking version at less than half the price:

    Bass tuning pegs:

    (I just sorted by reviews.)

    Stayed with the understated black Pahoehoe black (18-21" scale length):

    May consider raising the bridge to make it easier to to avoid fret buzz, especially with the E and A strings, but it actually plays very nicely as is, even unplugged! Now I just need to fiddle with my Pignose amp to get that sounding a bit cleaner... use batteries rather than (ungrounded) outlet power supply?


    I like your innovative thinking. I started to do this same thing to a junker classical only I was going to add 8 strings to make a mandocello. I never did finish it and I threw it away in a move. But you, Panda, you followed through. Well done. Let's get together and play.

    1 reply

    5 years ago on Introduction

    Cool idea, and nice instructable! A couple quick suggestions--

    1. When removing the old strings, don't just cut them if there is tension on them, loosen them first. Sometimes a tight string can whip unpredictably.

    2. Checking out the donor guitar for tone and action. The tone should be "warm" enough that it can handle some low notes. You might need to decide (or get an experienced guitar person to decide) if the neck's truss rod exists and can be adjusted, if the saddle can be raised or lowered as needed-- in short if the action is workable. -- I think the investement in tuners and electronics and strings would make you want to be pretty careful about choosing the guitar.

    3. Plan ahead with the tuners. Not all guitars have that kind of headstock so it would be good to make sure your guitar and tuners will play nice together.

    1 reply

    Yeah thanks, some good points that I missed. I did rush because I'm intending to use this as an instrument in our band.

    Thanks, Panda