Another Squier Bronco to Bass VI

Discussion in 'Luthier's Corner' started by BrassedOn, Jul 31, 2021.

  1. BrassedOn


    Oct 11, 2018
    I picked up a used 2006 Squier Affinity Bronco bass just because it was a good price and thought I’d be fun to try short scale. Okay, but it didn’t do it for I converted the 4-string stock Bronco (~40-100s) to 6-string Bass 6-ish. An actual Squier Bass VI is not crazy out of reach, but I had the Bronco, some parts, and I enjoy a project. And I don’t particularly need a Bass 6, not for any reason other than to have fun, and experiment with a different voice. But absolutely non-essential. I was not going to blow the budget, so looking for a cheaper route. And without all the pickups, switches or trem, it’s fair think of this as a Bass 6 “format”.

    I was looking at top loading bridges (which would be less work), but I went with the Fender Toronado Bridge Assembly, $30ish, which is string through. I like the lip at the tail end, just like the Bronco bridge, and 6 saddles. I thought it’d match the screw pattern….the front 3 screws matched exactly, but the back two not at all. But easy to drill. The silhouette is an excellent match to the Bronco plate, so no exposed areas where the worn finish wouldn’t match.

    So string through….the hard part, beyond defiling a perfectly good bass, is drilling the holes so the ferrules line up on the back and drilling out for the ferrules and the lip. The Ernie Ball and some other bass 6 strings have the smaller guitar ball ends. But if bass string are used, the bass ferrules are quite wide in diameter and with the lip/flare at the top would be too spread to line up with the guitar bridge. I came across the “Swhmc 2pcs Set Chrome Guitar Mounting Ferrules Through Body Instead String Bushing”. Just rolls off the tongue, right? This is a one piece guitar ferrule plate. And I think, if desired, there is enough material that I could bore out the ferrule to the bass string ball end size.

    There was lot of drilling for the string through the body. And the ferrule plate hole spread is just 1mm narrower than the Toronado bridge, .5mm each side. So I adjusted for that when I bored out the holes, so bridge, body and ferrule line up with no binding on any strings. Yes, I had to drill out the ferrule string holes and the bridge at the E and A positions to take the low strings, and went ahead and did all 6. NOT TOO MUCH, or the guitar ball ends would fall through. I think .110” bit to take the .090 string. (.14” could swallow the ball end). And important to file and sand any burrs. Installed, the ferrule plate is about .07 inches above the surface of the guitar. A bit thicker than a US Quarter at .06”.
    The nut was easy, I used the Musiclily 42mm slotted 6 string guitar bone nut (2 pack), which is mostly precut to fit. Of course, I still had to deepen the slots. Spacing turned out very good. Still need to touch up, take off a little meat, but now mostly right.

    Keeping the Bronco pickup, for now, and my original tuners plus 2 added cheapo tuners I already had. Someday upgrade to Gotoh?

    I decided to go with the 4+2 tuning machine layout, so not moving the original tuners. Online there are a couple of videos of similar conversions with guitar size tuners aligned all on the left side, which requires filling and redrilling. Tried to get some reasonable string spread, but not entirely happy with that, probably some Ill effect. Moved the string tree a touch. Not quite right. Future work. Label that part of the bass ‘in progress’.

    I went with the Ernie Ball 2837 Bass six set “6 string bass guitar Slinky”. Round wound, no coating. 20w-90. Important with Bass 6 strings is where the taper starts at the nut end of the strings; some brands are longer for the actual Fender or Squire Bass 6 with the tremolo. Others for hard tail kind of set ups. With the string through setup on mine, the taper for the bass E string was right at the notch for the first tuner. Barely right. The rest had some distance after the nut and before the tuning machine. Fine. The A string was just barely long enough for almost 3 wraps. I did not cut any off that string. Overall, the set worked fine. Estimating tension, the original 4 string I think was about 120 lbs total, and that jumps to EB 6 string 168 lbs. So while .95 for the E might be better, I’m not sure how much more tension I could add.

    It was quite a time to do the first set up and intonating. The bridge placement same as the original Bronco (which was slightly off alignment) fit fine. Just had to cut 3 loops off the spring to get the low E saddle back far enough.

    I’m satisfied with the Toronado bridge. Saddles are thin material bent to shape. And the screws seem cheap for fender. But overall, good purchase for look, feel, and function of the bridge plate itself. HOWEVER, I used my original Bronco bass bridge screws, a little fatter and tall compared to those that came with the new Toronado guitar bridge, and the screws push up the saddles a touch. Once I adjusted string height, it seems okay, but I need to watch carefully when I intonate to make sure the saddles do not catch on screw heads near the low A and high B strings. I could always fill those back 2 holes, redrill, and use the included Toronado screws.

    I like the 4+2 tuner layout. Need to upgrade the machines and work on string trees. Not happy with how the strings fan on the headstock. Maybe less of a worry with no trem. But looks bad and probably has some ill effect, so that I’ll ponder before the tuner upgrade.

    With round wounds, the original pickup (which is basically a 6-pole single coil in the middle position), and those Bronco whatever pots, decent range of tones. I can get a plausible tick-tack sound. Considering I’m terrible with pick. In terms of tone, I think round wound is a good brightish Bass VI sound, and anyway I’d want a contrast with my daily driver Fender P bass with flats.

    I think under $65 in parts and strings on a $100 bass I already had, so I can up the budget on the new tuners. Down the road I’ll think about a pickup if needed. Anyone have a pickup recommendation on a Bronco, like maybe rails for humbucking? The rout would also take a standard guitar humbucker I believe. CD9EB020-7C01-439C-BC32-E60F1E095A42.jpeg

    Final take, “It’s ALIVE!!!!”

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    Last edited: Jul 31, 2021
  2. lordofthebass


    Nov 9, 2021
    you figure this could be done on a standard scale steel string acoustic?
    Beej likes this.
  3. Beej


    Feb 10, 2007
    Vancouver Island
    Absolutely - in essence you're describing a classical bass guitar (aka classical contrabass guitar). I've "converted" a couple of acoustics into them by stringing up with a combination of acoustic bass and acoustic guitar strings. Specifically, Ernie Ball Phosphor Bronze (EB PB), because the bass and guitar strings are identical except for ball-end size and length. They tonally match. :cool: I have used a set of EB PB 13-56 medium guitar strings. From the guitar set, use the low E through B strings as your new contrabass A, D, G, B, E strings. Pick up a single Phosphor bronze .80 gauge string and use that for your E string. On both guitars, I put it on first and strung it up through the body by going in through the soundhole. The final gauges will be 80, 56, 46, 34, 26, 17. I also filed the nut for the larger strings. Tune it up an octave lower than standard and off you go. :) It's a bit of a floppy player, but that seems to be the feel of those instruments. No question they are fun to play. :woot:
    Last edited: Nov 26, 2021
  4. BrassedOn


    Oct 11, 2018
    Sounds like you and Beej are describing a standard guitar not a bass, right? Yeah sounds good, I think that’s workable with the light gauge set up Beej suggests because of the extra tension, better on a heavier built guitar, maybe laminate for the strength and maybe add to the bridge plate.

    But if converting an acoustic bass from 4 to 6, there’d be a few things I’d look at.

    Overall, is the bass more heavily constructed? Because the string tension would jump. And are the neck and fingerboard wide and thick enough to accommodate two more strings. And the head stock with enough meat to take 2 more machines. Above, Beej is suggesting a light set of acoustic strings. That’s smart for this kind of set up. For the Bronco I stayed with .090 on the low E, but you can see my estimate in the increase in pounds.

    And at the acoustic bridge there’s a lot to consider. If it’s a string through the top bridge, the string goes through the bridge, the top spruce, and the bridge plate. If you keep the top and bottom string placement, you have to now drill and put four holes where currently there are two. That’s a lot of wood loss, so I think you would need to remove the bridge and plate, fill the top holes, and replace the bridge and bridge plate with new material (and thicker bridge plate). Then drill all new holes, sized to whatever strings and ball ends and pins you have chosen. If top loading bridge, I’d replace that with new and add to the bridge plate. My 5string acoustic bass had top loading bridge with a metal insert at the ball end, which seems smart.

    So for an acoustic bass, from4 to 6, sounds like a lot of work. If I were taking this on, I might think about finding a bass kit if that’s available and which could be modified before assembly with bracing etc. and to start I’d check for anything in the luthier corner.
    Beej likes this.
  5. 20220105_221843.jpg 20220105_221852.jpg 20220105_221903.jpg
    Just finished my Bronco to vi conversion. Had an after market telecaster pickup with string-through bridge an a couple guitar tuners. Added a 3 position micro switch. Carefully routed the pickup cavity after measuring multiple times for scale length. Soldered new pickup and micro switch.
    Like the OP I do not really need a Bass vi but was a fun project. Not to mention a lot of fun to play.

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    BrassedOn, Beej and Matt Liebenau like this.
  6. BrassedOn


    Oct 11, 2018
    So officially we got a trend!

    congrats on the build. Looks like you did quite a bit of shaping at the headstock and moved the original tuners?

    For me, still fun, and my picking is improving. Seems so much easier on short scale and narrow string placement, but also able to transfer that skills to my full-size bass. It was always doable, but Bass 6 inspired more practice.
  7. Thank you BrassedOn. You are correct about the reshape of the headstock. Since I was using a guitar nut I wanted as little angle as possible between it and the tuner. I am thinking of getting a smaller set of tuners to replace the original 4.
    Our band has just one guitarist. I have started to fill in with some chords with this. A bit of getting used to but I like the sound. It does serve the purpose.