Epiphone 335 – LR Baggs T-Bridge Install
South Austin Guitar Repair
Wow. You know it’s a busy year when I took pictures of a project from February and have not got a chance to write about it until September.
Well, this was a noteworthy project to me. I love electronic mods to guitars. They’re magic to me. This one in particular was as much of a challenge as rewarding when finished. There isn’t much info on the T-Bridge system aside from purchasing and the product page on LR Baggs’ site. I hope this blog post can serve as a reference to other luthiers trying to find installation tips for the T-Bridge as I was when I took on the job.
The T-Bridge allows a guitar to blend the magnetic pickups with a piezo pickup in the bridge. The piezo pickup acts as a makeshift acoustic guitar for those who don’t want to change instruments between songs. It installs discreetly with a hole drilled under the tune-o-matic bridge to feed the 6 wires. From there, you can decide which way you want to wire the controls.
The customer wanted a separate output jack for the T-Bridge so he could send the signal to a separate amp. The controls were then wired as 2 volumes and a master tone, with the T-Bridge volume in place where the bridge tone knob was originally located. It is possible to wire the T-Bridge into the same circuit as the magnetic pickups and have a single output for the guitar. But wasn’t requested for this install.
Most aftermarket guitar mods come with some sort of “gotcha” or hiccup in the process. The T-Bridge was no exception. Two major hiccups, as a matter of fact. I didn’t manage to get pictures of them since I was preoccupied trying to finish the job on time. The first problem: There are two standard sizes for Tune-O-Matic bridge posts. Let’s just call them wide and narrow for simplacy. The bridge posts originally on this guitar were the wide variety and the T-Bridge were the narrow. The old holes for the bridge posts had to be doweled and re-drilled before anything else could move forward. Fantastic…
The second problem (and this one is a lot less inexcusable), the T-Bridge volume pot, is short shaft. So after wiring the system up, drilling irreversible holes into the customer’s guitar, I feed the electronics into the guitar to find the shaft of the pot is not long enough for the nut and washer to catch on the top side. This makes absolutely no sense to me. A short shaft pot only works when mounted to small distances; a pick guard (like a Strat or Tele). It doesn’t span the distance necessary to mount on a carved top body. What is infuriating about this, you know Baggs made this bridge to work as a direct replacement for Gibson guitars. After all, they are the biggest brand to utilize the Tune-O-Matic bridge. NEARLY ALL GIBSON GUITARS HAVE CARVED TOPS. A SHORT SHAFT POT DOESN’T FRIGGIN’ WORK! And I can’t exactly route the underside of the cavity on a guitar with a glued top, who’s electronics are fed through the F-holes. Oh, and I didn’t mention this pot is 5 meg. An uncommon potentiometer value, which barely exists in the outside electronics manufacturing world, much less the electronics intended for guitars. I contacted LR Baggs, they said they don’t offer a long shaft version of this pot. I had to find one on my own. Great customer service fellas!
Fry’s is the only electronic store in town that might carry something like this. They do not. After searching online, I came across a company which had a 5 meg pot A set of two cost me $20. They took a week to ship to me, setting the project back. When they arrived, I was heartbroken after wiring up the pot and finding it was too large to fit into the F hole. It’s things like this that drive me crazy, when working on projects. At this point, I contacted the customer and let him know the situation. Thankfully, he was an understanding guy and sympathized. I contacted LR Baggs again, asking what the alternatives were, given the circumstance. The lesser of evils ended up being a 1 meg pot. These are typically found in the upper circuit of Jazzmaster guitars and are readily obtainable. I even had a few in my shop, ready to go. 1 meg pots have a warmer sounding value than 250k pots, which are typically used to dampen the brightness of the single coil pickup. Piezo bridges are naturally and overly-bright. This is because of the way the piezo transducer converts string vibrations to sound. The purpose of the 5 meg pot was to help dampen this occurrence. The 1 meg pot, would not effectively dampen the brightness of the piezo, but is the closest that we could get, and still perform functionally. The end result, the piezo was a bit brighter and the customer will have to roll back some treble and presence on his amp so the T-Bridge doesn’t make his audience’s’ eardrums explode at the next gig.
All this aside, the T-Bridge is a cool innovation and a highly functional upgrade for a guitarist that appreciates a multi-function instrument. I just wish, for the love of luthier, LR Baggs, get your shit together and provide us with a long shaft pot! Simple stuff!