We rarely see Kahler equipped guitars in our shop – I don’t remember seeing any at all in the last seven years. Yet over the last two months we’ve seen at least five (three of which we removed and returned the guitar to stock, like so: http://www.strangeguitarworks.com/filling-a-kahler-route/). A few weeks back our friend Gregg asked us about installing a Kahler into his 7-string PRS, and who are we to say no? This was a unique challenge – here we go!
A while back we refretted Gregg’s PRS with stainless steel frets, routed the body for a single coil in the center position, and installed a Sentient/Vintage Staggered/Nazgul set of Seymour Duncan pickups in it. While it sounded and played great, Gregg wanted to take it up a notch with the Kahler. Here’s how it looks before we started:
First I had to remove everything from the body, to make room for the router, and then make careful measurements to ensure that the Kahler bridge would be precisely located. When installing a Kahler, it’s absolutely critical that it’s set exactly in the right place: even a millimeter out of spec and it won’t play in tune. This process of mapping everything out was made even more complicated by the fact that there are no pre-made Kahler routing templates out there (that I’m aware of), and I had to make one from scratch. Plus, the blueprint in the Kahler instructions was WRONG! I’m really glad I took the “trust, but verify” approach here: I tested the template on the bridge before I started cutting into the guitar, and it didn’t fit! I ended up having to create my own blueprint for my routing template, which was by far the most time consuming part of this job.
Next step: routing! We’ve done so much of this over the years, that it’s only slightly scary now. (A reasonable degree of fear when drilling holes into somebody else’s guitar ain’t a bad thing.)
Before installing a Kahler, it’s always a good idea to test how the strings line up with the neck before screwing it down.
It’s a good thing that this was tested before I put the whole thing back together, because I realized the the Kahler was going to be too tall, and the action would have been super high. Gregg is a killer player and likes a super low action, so this wasn’t going to fly. Since the PRS was an arch top, and the Kahler was designed to go on to a flat top instrument, the geometry was way off.
I ended up having to recess the Kahler into the body by 4mm. I screwed the bridge down in it’s proper position, and then scored the finish all the way around. Then I removed it, taped it off, and used our Dremel to create a recess for the Kahler’s perimeter by hand. Slow and steady!
With the routing finally complete, I set the bridge into the body, put all the electronics back in, and did a complete setup. We also installed locking tuners, which eliminated the need for a locking nut. Once I was done, I gave it a spin, and really put the Kahler through a lot of dive-bombing abuse (I may or may not have played some of my favorite Adrian Belew licks during testing). It plays, and STAYS, perfectly in tune! Huzzah!