I've written about making these bridges before for old Gibson basses that need a little TLC without the cost and impact of a full neck reset. The last one I made was a 2-post bridge which, in all fairness, was never really a great idea as the tension on these bridges is immense, especially on the long scale versions like this, which is why Gibson quickly developed the 3-post version here.
This one came in to discuss the options we had as the owner hadn't played the bass in years due to the bridge being down as low as it would go, and the action still being way too high. The neck was straight, and the frets were good, but it was almost unplayable as it was. The rest of the bass was actually GREAT and almost all original.
We discussed a neck reset, which as I explained is expensive and invasive on the instrument or making a new bridge that could be lowered down enough to get a great action. The owner left it with me to take some measurements and talk options.
I measured the action from the top of the frets with the original bridge removed which confirmed we could indeed make a bridge that would work. The owner, like the other one I made, was keen to keep the bass as original as possible and have the new bridge only use existing holes and mounting points. This way if they ever want to go back to an original bridge in the future it will just drop in.
With the new bridge confirmed I bought some aluminium and started designing and cutting pieces to suit.
This bridge is simpler and less "structural" than the 2 post as we now have that front anchor point which as I mentioned helps immensely for stability and strength.
The idea itself is essentially based on the standard Fender P/J bass bridge although instead of folded steel, I use aluminium which is easier to work with by hand. I don't have access to CNCs or a full metal working shop so like everything I do, it's all done by hand.
With all the measurements and sizes confirmed I cut, drilled and assembled the bridge in rough form and attached it to the bass to make sure it was going to give me enough adjustment in both height and intonation, which I had in excess.
I then pulled it apart, did some more aesthetic shaping and cleaned up and polished all the parts before reassembling and drilling the holes for the strings, which anchor from behind just like the Fender unit.
I actually love doing stuff like this as long as the customer isn't in a huge hurry, which they haven't been. I find it very therapeutic to make stuff like this and the idea of making an old guitar or bass playable again without huge stress (and cost) on the instrument is incredibly satisfying.
With the new bridge on and anchored properly it was simply a matter of a fret dress and setup with flat wound strings. The Fender barrel type saddles gave me all the adjustment I needed, and I honestly think these bridges sound and sustain better than the original "floating" pot metal bridge. I'm a HUGE fan of the Gibson wraparound bridge, especially on guitar, but having the bridge anchored securely directly to the body on these basses makes a noticeable difference to the vibrations running through the body and, I think (imagine ... feel?) they have a more rounded bottom end.
These basses, despite only having one pickup, which was designed by the great Bill Lawrence, are very versatile with the addition of quite unique wiring in the Gibson bass world. The 3-way switch is essentially a series/parallel/tone affair (not coil tap as some suggest) which in conjunction with the choke, gives 3 distinct tones from thin to THICK. The choke, which is the same used in the Ripper, along with pot (300K and 250K) and cap (0.1 and 0.47uF) values not commonly used in other basses shows that Gibson was actually trying to make this bass sound ... different to other Gibsons and basses at the time. The pickup, while looking like a typical Gibson humbucker is also unique to this model and along with the long (34 1/2") scale really makes this bass thump.
This is a great bass and now has another lifetime of playing in essentially all original form (it can be reverted back without ANY modifications) for the owner. These basses used to be quite cheap and are still around for reasonable prices especially if they have a somewhat questionable bridge, which most do. So, if you see one at a good price with issues like these, grab it and get someone to make you a decent non modifying bridge and you'll have yourself a great vintage bass.