My acoustic guitar to bass conversion

[shwabilly]

For years I've been reluctant to purchase an acoustic bass, because I have never been able to find one loud enough to compete with an acoustic guitar without amplification.
Which is what I'd want it for.

Recently, I was watching a YouTube video where a guy converted an acoustic guitar to bass.

Upon thinking about it, I remembered that I had an old, big bodied acoustic that was given to me by a friend over 20 years ago. I've been in my current house for over 5 years, and it has been in storage in my basement since the day I moved in.

With very, very low expectations, I slapped a set of bass tuners on it that I had, as well as a bass tailpiece, a nut i had and threw some strings on.

Much to my surprise, it plays near perfectly. It set up very easily, and the action is awesome. It was a horrible sounding and playing guitar, but it is a fantastic little bass.

The big body lends it some volume. Playing it with a pick, it is louder than any manufactured acoustic bass I've heard.

Needless to say, I'm very happy. It's my new couch bass, and I'm going to bring it to the next campfire to see how it makes out.

 

[CatSquare]

Oh my. That's really cool, I'm jealous and inspired!

 

[Bass Viking]

and I'm going to bring it to the next campfire to see how it makes out.

I hope you're not planning on burning it!

Cool instrument. Can you post a video or sound clip?

 

[shwabilly]

I was going to post a video with my phone, but the sound quality was garbage, and didn't represent what it actually sounds like.

 

[Andy5997]

I have a junk f hole guitar in my practice room I'm gonna try this with. Thanks for the info

 

[n4vgm]

I just converted an Esteban dread using a short trapeze tailpiece and it's working out better than I imagined. I want to add a soundhole pickup but I will DIY a hot rail Strat into a wooden holder. Sorry no pics at the moment, I will try to get some up soon.

I think one reason it works is that with a short trapeze tailpiece the length from nut to the ball is over 30" so you are gaining some tension. Action is a bit high for me but from what I read the average ABG is on the high side. My main bass is a homemade "UBass" plus an Ibanez Mikro with flats.

 

[n4vgm]

As promised . . .







I thought the original bridge/saddle would be unusable but turned out the intonation is not that far off if I tune it to the fifth fret. I had to put a piece of foam under the strings to cover the holes and screw dots but also to mute the backside string sections from ringing.

 

[fjadams]

Both of these are just making me have to do the same. I can see the future!

 

[n4vgm]

It sure helps if the cost of the "volunteer" is $0! I'll only have about $60 into my conversion and if someone has extra parts laying around they may need only a couple items. If I had more time I might have checked the parts bin at local music stores.

Hack On!

 

[fjadams]

I'm checking eBay Project Guitar everyday. One will have to come up pretty soon. They always do.

 

[n4vgm]

My conversion is now waiting for my DIY soundhole mount of a generic dual rail pickup. I could just mount it in a piece of paint stir stick and screw it to the top but that would look to scetchy even for me. I'm planning and slowly creating a removable all-in-one pickup that will include VOL/TONE controls recessed in the sound hole. I think there will be room as the 4 strings take up less width than the original 6.

This guitar was owned by my wife's mother (RIP) who never actually played it but my wife let me convert it as long as I promised all changes would be reversable.

 

[DredFetus]

This is very cool. Want to know how it sounds might make one myself.

 

[n4vgm]

Finally got the pickup done, installed and tested. Works great except for a little hum which could be from not having the strings grounded or the fact that the pickup was $7. I just EQed it out. Sorry the closeups are hard to see, the pickup is black in a flat black mount. I made the mount with paint stir sticks (free from Home Depot) foam from left over mousepads (also free) and glue (that I bought).

The cord I used was 1/8" mono but I cut off the male part (ACK!) and it then attaches to another cord that is 1/8" m --> 1/4" m (mono) and I will just stuff the attached cord into the body. That way if I ever decide to permanently mount a 1/4" jack I can just cut the cord and solder.

I tested it into my Hartke A25 and it sounded great, the vol/tone work as they should. I then ran it through a Zoom B1 and now I have several usable sounds that are noise free including auto wah. I will try it with the band tommorow and see if they like it better than the DIY UBass I have been using (semi-acoustic Indie cover band).

Unplugged, the mounted pickup lowers the acoustic volume a bit but I figured it would. Overall I'm pleased with the outcome and recommend anyone wanting a short scale ABG think about converting a cheap acoustic. You can even just add a cheap soundhole pickup rather than create your own like I did. But I do have vol & tone controls at my fingertips on the cheap.

 

[sissy kathy]

As you know (or should) higher tension strings will yield greater volume. Since you're going from ~160 lbs w/six strings, you could use some higher tension (up to ~40 lbs ea) rounds to increase your tension to maximize your volume.

 

[n4vgm]

True, Kathy, and one aspect is the string set I had laying around were light gauge round wounds so I can always go thicker. Using the short trapeze tailpiece was intentional to increase the actual string length so the tension would increase. Moving up in string size would mean I will have to put real bass tuners on and make it harder to play. Everything's a balance of priorities.

I used it at rehearsal yesterday and the band agreed it sounded more focused than the DIY UBass plus I had much more control of volume while playing. Feedback reared it's ugly head a few times but part of that is our rehearsal space is a highly reflective, just a normal bedroom. I was playing through the PA.

 

[AngusF]

I've got a six string classical that's just begging for this treatment. Thanks for the inspiration, folks!

 

[n4vgm]

UPDATE - I have now been using this creation for over a month and it has really proven to handle a wide variety of tunes. The band plays Americana & Indie with a few pop/rock. We are very close to gigging so I decided to put real bass tuners and new strings on it. I now have a set of chrome Gotoh compacts and a custom set of D'Addario Nickel plated steel rounds for installation this weekend. I will have to drill out the tuner holes but not by much so I will just go slow and drill halfway from each side of the peghead. To even out the feel I'm moving from the old set of 40, 60, 75 & 95 to the custom guages of 40, 55, 70 & 100.

So basically this conversion was worth the time and money and gives me an electric bass that fits in visually with acoustic guitar, mandolin & dobro but lets me mod the sound with the multi-FX. Oh, and it works unplugged too!

 

[reddesert]

This totally awesome thread inspired me to do the same thing to a decent entry level guitar with a repaired greenstick fracture of the neck. A cheap bass tailpiece and nut and a cut down set of strings later:

It's surprisingly effective and is a blast to play. The action is actually a bit too fast - the low tension gives some fret clang and very little neck relief. I don't think the extra string length from tailpiece to bridge increases the tension (tension depends on sounding length), but it means you could use stock short-scale strings. I still have the guitar tuners on, so I had to unwind the E and A strings and put the core through the tuner. The guitar tuner holes (3/8") are pretty close to the edge of the headstock, so I think it might be safer to drill new holes for bass tuners than to enlarge these.

I'm trying to figure out what are a good set of relatively higher tension short scale strings. Most short scale strings don't come in medium or heavy gauges. Flatwounds like Chromes are an option, though I wonder if they would be lower acoustic volume than rounds.

 

[n4vgm]

Dude, you NAILED the concept! Using a SHORT tailpiece is key to getting that little bit of extra tension. What you describe is about what I expirienced. Acoustically, the lower tension does affect the playability for sure. As for Fret clank, I find that I need a medium touch and try to play just behind the frets. That way I'm not sharping the note by pushing the loose string down between the frets. I use a pick most of the time.

My string "length" measures out at 30.75" from the ball to the nut so the extra amount from the short tailpiece does make a difference. The actual scale is 25.5" from the saddle to the nut. That's 5.25" to raise the string tension!

I went with the DIY magnetic pickup that also works well for amplification. Another lesser benefit of this mod is that if you need a case/bag you can get a standard AG one for cheap (or like me I had an extra). I also added a strap button on the side of the neck heel, worked great.

BTW, do you notice a high pitched ringing from the sections of strings between the tailpiece and the saddle? On mine it was very noticable but I put a piece of mouse pad under the strings behind the saddle on top of the bridge. Also hides the peg holes!

If you like D'Addario strings you might try this website - String Tension Pro

Many of their sets are available in short scale and the thinner strings are the same diameter all the way along so you can use medium/long for odd sizes. I used bassstringsonline.com because they seem to have a great selection of singles (also a TB supporter I understand).

 

[Will_White]

My string "length" measures out at 30.75" from the ball to the nut so the extra amount from the short tailpiece does make a difference. The actual scale is 25.5" from the saddle to the nut. That's 5.25" to raise the string tension!

the only thing that matters for tension is scale length, anything beyond the nut and bridge Is is just extra, they only thing it does is allow the string to stretch more which could lead to lower perceived tension.