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4-to-5 string conversion

Tpi

Jun 18, 2023
256
437
First off, yes. This is crazy, I am crazy, What a crazy thing to do. The crazy things you see these days. You now have thorough understanding of this post and need read no further. :)

This is a $90 shipped ebay purchase. It almost went to a local community fundraiser, but they stopped accepting by the time I got there. Now, it's mine for experimentation.
pre_cheese_01_.jpg


The nut is 41mm which I consider wide for a 4 string. 41mm is also smaller than the smallest 5-string neck around 43mm+.

To me, 41mm would make an excellent (albeit tightly spaced) 5-string with ideal bridge pitch of 14mm. 15mm is getting too wide for this neck.

Here's what that looks like.
Four spare Ibanez SR300 tuners + one stock
pre_cheese_02_.jpg


And just as importantly...There is plenty of edge space on the B and G and they fit within the stock 4 pole passive pups. Good enough for this experiment.
pre_cheese_03_.jpg


As you can see though, while the bridge is the perfect width, how do I brace that center string? Another saddle in front of the others won't work for intonation. The 2 saddles can't be welded as I have no welder and again lose 'precise' intonation. Can't add material on top of the saddles for the height disparity it would cause.

And yes, I simply drilled through the body, added ferrules on the back side and voila, through-body strings. And that other bridge down there...
pre_cheese_04_.jpg


This is the tightest 5-string bridge I could find at 16mm for $25 shipped. 16mm is 2mm too much. My option here is grind down ~2mm of distance from between each saddle and then pin the outer saddles so they don't wobble around side-to-side or slip out of final position (once known). This bridge allows for behind-bridge strings and through-body if I want to.

Status. If I hadn't 2nd guessed myself on the nut, I'd have it done I've done some painting and it's ready for the local Tech cut a new bone nut this week. While I await that, my option is to start grinding the 5-string bridge and consider how thin a piece of aluminum I could slip under the center string on the 4-string bridge and would it slip out with playing?

I am determined to make this work. I don't know how yet. Maybe someone here does. I don't have access to grenades, flamethrowers, burn pits, chippers, chainsaws, hatchets, large garbage disposals or shady 'friends' with 'suspicious names' who 'fix things' for 'you'. Nor is there much of any budget. What I do have is access to tinker-grade tooling, open ears and mind.

Anyone?

PS.
$90 Bass
$70 Paint
$45 Bone nut
$25 Bridge
$00 Ibanez tuners
$00 Spare strings
$230 subtotal. I may be able to justify another $20 to the project. It would otherwise revert to a 4-string with a 5th tuner. ;)
 
Last edited:
First off, yes. This is crazy, I am crazy, What a crazy thing to do. The crazy things you see these days. You now have thorough understanding of this post and need read no further. :)

This is a $90 shipped ebay purchase. It almost went to a local community fundraiser, but they stopped accepting by the time I got there. Now, it's mine for experimentation.
View attachment 5170938

The nut is 41mm which I consider wide for a 4 string. 41mm is also smaller than the smallest 5-string neck around 43mm+.

To me, 41mm would make an excellent (albeit tightly spaced) 5-string with ideal bridge pitch of 14mm. 15mm is getting too wide for this neck.

Here's what that looks like.
Four spare Ibanez SR300 tuners + one stock
View attachment 5170948

And just as importantly...There is plenty of edge space on the B and G and they fit within the stock 4 pole passive pups. Good enough for this experiment.
View attachment 5170952

As you can see though, while the bridge is the perfect width, how do I brace that center string? Another saddle in front of the others won't work for intonation. The 2 saddles can't be welded as I have no welder and again lose 'precise' intonation. Can't add material on top of the saddles for the height disparity it would cause.

And yes, I simply drilled through the body, added ferrules on the back side and voila, through-body strings. And that other bridge down there...
View attachment 5170958

This is the tightest 5-string bridge I could find at 16mm for $25 shipped. 16mm is 2mm too much. My option here is grind down ~2mm of distance from between each saddle and then pin the outer saddles so they don't wobble around side-to-side or slip out of final position (once known). This bridge allows for behind-bridge strings and through-body if I want to.

Status. If I hadn't 2nd guessed myself on the nut, I'd have it done I've done some painting and it's ready for the local Tech cut a new bone nut this week. While I await that, my option is to start grinding the 5-string bridge and consider how thin a piece of aluminum I could slip under the center string on the 4-string bridge and would it slip out with playing?

I am determined to make this work. I don't know how yet. Maybe someone here does. I don't have access to grenades, flamethrowers, burn pits, chippers, chainsaws, hatchets, large garbage disposals or shady 'friends' with 'suspicious names' who 'fix things' for 'you'. Nor is there much of any budget. What I do have is access to tinker-grade tooling, open ears and mind.

Anyone?

PS.
$90 Bass
$70 Paint
$45 Bone nut
$25 Bridge
$00 Ibanez tuners
$00 Spare strings
$230 subtotal. I may be able to justify another $20 to the project. It would otherwise revert to a 4-string with a 5th tuner. ;)
Official Exquisite/Glarry/Burning Fire Bass Club?
 
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You could make a single saddle out of brass or aluminum that’s held in place by the E and G screws on the stock bridge. Will require filing to set the intonation, but you could individually mount and intimate each string with the stock bridge, measure exactly where they intimate, and file those measurements into your one saddle.
 
Add the 5th tuner hole, buy a cheap 5 string bridge with threaded saddles, buy a cheap 42mm string nut blank see how it sounds if good (yer good) if not buy some cheap blade pickups, easy peasy.
 
I've done 425 converstions using a Schaller 3-D5 bridge on P and Jazz basses. The bridge is adjustable with rollers. The one below is a jazz bass with a precision neck and has a string spacing of ~17 mm, but it can be narrower. The members Ric5 and Mapleglo have threads about their 425 conversions that were useful.

View attachment 5171124

Jesus wept that’s disgusting
 
You could potentially use individual bridge pieces, like on some of the fancy basses like Dingwall ... they can be had fairly cheaply on ebay, and I think can be narrow enough for your purposes.

Or, that single bridge bar thing :).
 
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I’ve made makeshift bridges out of threaded rod for testing prototype oddball instruments.. 2 segments of rod, for 2+3 strings, tap them for height adjustment grub screws and some means of controlling adjustment along the string length (intonation).

I believe I’ve seen 15.5mm but I couldn’t tell you where offhand… look on hipshot’s site and see..