2000s Roberto Acha Bajo Cuarto Conversion

Overview: I have been Jonesing to work on a bajo quinto-style instrument for a while but have been holding-out to find one on the outrageous (and funky) side as my plans always involve a bit of modding. This one popped-up on eBay "in a state" and with the "tie block" back-half of the bridge missing, so it seemed like a good candidate. It also has frigging ponies inlaid everywhere, a double-cutaway, and all of the eye-catching silliness one could desire from one of these. It also looked like it had a lot of regular gigging use put into it and I'm a fan of worn-in and ready to get scratched.

Anyhow, this started-off as a normal bajo quinto but I've modded it to a 4-course (rather than 5-course) instrument of the style being called bajo cuarto these days. That would usually leave the tuning DGCF low to high with an octave D course, but I'ved tuned it up here to EADG with the strings all in unison. That makes it like guitar's low 4 strings but with doubled, mandocello-sounding courses. Perhaps that makes it a bajo yanqui? In any case, my bass-playing brain can immediately adapt to it and I don't have to transpose anything.

Feel: The neck is ginormous and manly but I'm enjoying the way it makes me rethink playing something like this and I like that the fourths tuning makes it very useful for faking mandocello-style lines for recording.

Interesting features: Like a lot of these eye-catching bajos, it's overbuilt and very rugged and so it doesn't have a ton of acoustic volume. As long as you're playing with others who don't pick like they're trying to put a hole in their guitar (I'm looking at you, Rob), it will cut enough in a jam situation. For the vast majority of bajo players, though, the standard practice is to slap a soundhole magnetic pickup in there and play it through an amp or PA so the acoustic sound is a lot less important than the stage-ready sound. I've fit a K&K acoustic pickup to it for the plugged-in experience so you get a more natural, acoustic sound.

Repairs included: Unfortunately for me, this poor beastie needed a board plane and refret before I could do anything else and it needed some spot repairs to a seam-separation at the neck/headstock joint and a repair to a wing of the headstock. After I addressed that, it just needed a new nut and saddle (both bone) and I then modded a reso-style tailpiece for string mounting. Once done, I added some "downpressure bolts" behind the saddle to ape some of the "bridge pull" sound of the tie-block-style bridge that would have originally been used. This gave it more of the traditional sound back and added some warmth as well. I then installed a K&K pickup and it's setup and playing spot-on.

• Weight: 5 lbs 10 oz
• Scale length: 24 7/8"
• Nut width: 1 3/4"
• Neck shape: big U/C
• Board radius: flat
• Body width: 15 1/8"
• Body depth: 3 7/8"
• Top wood: solid spruce or similar
• Back & sides wood: palo escrito ("Mexican rosewood")
• Bracing type: tonebar/ladder
• Bridge: palo escrito
• Fretboard: rosewood
• Neck wood: a mix of mahogany and something else
• Action height at 12th fret: 3/32” bass 1/16” treble (fast, spot-on)
• String gauges: 54w, 42w, 32w, 24w (doubled)
• Truss rod: none
• Neck relief: straight
• Fret style: jumbo

Condition notes: It has mild-medium scratches and usewear throughout and the finish has rubbed in areas. I repaired a headstock crack on the "wing" near the low E tuner area and there's a smaller repaired crack area on the treble side near the waist. Both are good to go. There was also an old repair to the neck/headstock graft joint and it is holding-up nicely. Clearly, I've also modified it a bunch per the description above. The tailpiece string-load is not at all original but I do like the way it makes these instruments sound and feel compared to the standard stringing style.

It comes with: Sorry, no case.

Consignor tag: JW