Acoustic Guitar to Acoustic Bass Conversion

This instructable was made to convert an acoustic Guitar to Acoustic Bass.

You may be asking yourself why anybody would ever want to turn an acoustic guitar into an acoustic bass. Well I can’t answer for anybody else but for me it was because I had an old acoustic guitar lying around. So why not turn a guitar into a bass.

Sorry my camera has horrible audio. It sounds really good in person.

Step 1: What You Need

This is a fairly simple conversion and you do not need many tools. What you will need however is:
Grinder or dremal
Drill
Screwdriver
Welder
These tools may vary depending on your guitar

You will also need:
Scrap Metal
Hinge
Guitar (of course)
bass strings
tuner

For me I had an old guitar that was given to my dad a many years ago. It looked like a cheap guitar and had been sitting in storage with the strings on so the top was peeling away from the body. If you are lucky you may find an old guitar lying around or i am sure you can find an inexpensive one on eBay. I have seen them go for very little. But if you are going to go through that to buy one, you might as well just buy a bass.

Comments

[savvas_papasavva]

That's a nice mod, I've been thinking about doing something similar but was not sure if the neck of the acoustic would bend under the tension of the strings.

[who___cares]

I am planning to built one myself and got a question. Can't you just use the old bridge? Of corse by drilling two new holes.

[ArtieWallace]

I started out trying to learn the acoustic 6 string guitar and was not able to get the hang of it due to nerve damage in my hand. After a while I decided to try a 4 string Bass, that worked out much better for me. Sense then I been looking to turn my old 6 string acoustic into an acoustic bass. Everyone I spoke to told me “don’t waste my time trying to convert it”. Your instructions answered the few questions I had and could not figure out.

Thanks for posting on instructables.com. Your photos showed great detail and your instructions appear to be very basic. I think you answered the few questions I had, I will be trying to make the conversion and I will post how it worked.

Thanks again for sharing,
Artie

[jackf]

How do you think it would hold up on an old 3/4 length nylon? too much of a stretch?

[djframe]

what did u do to the neck? I did not see an explanation in the steps.

THX
DJ

[TheJoshinator]

If you can figure out how to adjust the truss rod in the neck, you might be able to use the B, E, A, and D strings from a 5-string set and tune them to a standard EADG. The thicker strings would require more tension for that tuning, as well as being shorter, and might be just tight enough to really be playable. You could also remove or grind down all the frets and just leave it as a fretless acoustic, thereby fixing your intonation issues

[zombeastly]

VERY VERY COOL!!!! is there any way to do this to an electric guitar?
thx

[rimar2000]

Nice work, well done.

"If you have any improvements that you can think of add it in the comment, please." I suggest you to change the plastic nuts (under the strings) with another made of bone. It is not difficult, and sounds a little better.

[mdog93]

also, it looks like thae action is too high on this guitar, that's the distance between the strigns and the fretboard for those who might not know.

Was this a steel string to begin with? and also what did you use the welder for?

oh and can you get nylon bass strings??

[peach_fart]

yes it was a steel string, i dont know about nylon bass strings, and the action is probably high due to neck warping. im guessing he welded the hinge to use as the tailpiece.

[mdog93]

yes, the strings will also be too loose when tuned to a bass tuning because he didn't lengthen the scale length to that of a bass guitar. The only way to make this technically a proper bass would be to move the bridge further back, if it would fit on the guitar still at the correct length, but then you'd either have to extend the neck and remove the frets fill the old slots and reposition them so the 12th fret is halfway between the nut and bridge OR remove the frets fill in and prepare new neck then refret the frets in the correct position, but this would mean you would have less frets overall

[peach_fart]

it could still be played like a bass at that scale but you would probably be forced to used a low tuning such as b standard

[mdog93]

well i don't deal with that, i only play standard EADG tuning. although if you are willing to put quite a bit more effort in it might be possible to turn an acoustic guitar into a proper acoustic bass by doing the things i said above, you just have to put a lot of time and effort into hiding the old marks and snagind it down and refinishing it to make it look nice.

I'd like to try doing it but its hard to find time these days and i don't have a spare steel string acoustic guitar and unless i ever find one cheap or acquire one i'm not about to buy one just to do that to it.

[Pryo Chain]

...or you could buy a bass and not waste a perfectly good acoustic...

[mdog93]

sorry, you seem to misunderstand part of the magic of instructables. Let me explain for you:

*Some things are cheaply made, and designed so are not very good at their job so people might modify or improve them- bringing me onto my next point
*If somethin is old, useless, unwanted, been thrown away by somebody else it can be RE-USED, or UP-CYCLED
*Another thing is saving money- some things are cheaper to make from scratch or by modifying or up-cycling something cheaper than buying one from a shop.
This is also better if somebody only wants the item for satisfactory use, ie.e they are not a bassist but would like to have an acoustic bass to play with and mess around but because they are not an expert they do not want to fork out £500+ for one and also if they did buy one they wouldn't be able to do it justice anyway and if they made one it would not matter if it got a little damaged.

Whilst i do not think this instructable is erfect as structurally i would be dubious about doing this without reinforcing the neck. However i would imagine many people would like this and make one, just because you wouldn't want to doesn't mean others can't. If you can't make any constructive criticism, please don't be destructive of what other people are passionate about and have spent their own time documenting for other people.

Want me to carry on?

[ComplacentBard]

It seems like the scale length would be very short for a bass and that the strings would have to be very loose.

Very ambitous, though

[toakhong]

Nice! I might try this after i get a replacement for my old acoustic.

Just one question. If you use an electrc-acoustic guitar for this, how would it sound when plugged in?

[iamtoats]

The same way you always did, through the piezo.

[peach_fart]

i think he meant would the sound drop off because the pre-amp was meant for guitar frequencies or if it would play the lower notes fine

[blindsagacity]

Hey, one the you could do to improve the intonation (though it would require a bit of work) is to move the saddle closer to the tailpiece to compensate for the effect that thicker strings have on intonation

[kyrisroy]

Cool, I have an old acoustic and this sounds like an awesome idea.

[Houdinipeter]

Great Instructable!

Oh and does the guitar have a truss rod? Cuz if not the bass strings might have to much tension on the neck... But let us know how it turns out after a few months!

[gmoon]

It seems somewhat unlikely that the bracing on a normal acoustic will be sufficient for bass strings--at least in standard tuning.

You could add more bracing to the top. That would require some major surgery, though.

I wish you luck with it, I hope it holds up to use. Maybe tune it down a half step or two...

I'm not sure how old that "Kay" guitar is, but if it has a solid wood back, top and sides, it was probably worth restoring as a regular guitar. Your choice, of course. It's probably not worth a ton of cash, either way...