The Frank Brocklehurst 6-String Fretless Bass Build

A few months ago, my Ken Bebensee 6-string fretted bass needed some TLC. You know, the one rocking those Pink Neon strings! I scoured my Connecticut neighborhood for a top-notch luthier and got pointed to Frank Brocklehurst, F Brock Music. He swung by my place, scooped up the bass, and boom, returned it the next day, good as new. Not only that, he showed up with a custom 5-string fretted bass that blew me away. I couldn’t resist asking if he could whip up a 6-string fretless for me. 

Alright, let’s break down the process here. We’ve got our raw materials: Mahogany, Maple, and Holly. Fun fact – the Mahogany and Maple have been chilling in the wood vault for a solid 13 years. Frank is serious about his wood; they buy it, stash it away, and keep an eye on it to make sure it’s stable.  

First up, they’re tackling the Mahogany. Frank glues it together, then lets it sit for a few days to let everything settle and the glue to fully dry. After that, it’s onto the thickness planer and sander to get it nice and flat for the CNC machine. The CNC machine’s the real star here – it’s gonna carve out the body chambers and volume control cavity like a pro.

While the Mahogany’s doing its thing, Frank goes onto the neck core. Three pieces of quartersawn maple are coming together for this bad boy. Quartersawn means the grain’s going vertical. He is also sneaking in some graphite rods under the fingerboard for stability and to avoid any dead spots. The truss rod is going to be two-way adjustable, and the CNC machine’s doing its magic to make sure everything’s just right.

Now, onto the design phase. Frank uses CAD software to plan out the body shape, neck pocket, chambering, and those cool f-holes. I had this idea for trapezoid F-holes, just to do something different. The CAD software also helps us map out the neck shape, graphite channels, and truss-rod channel with pinpoint accuracy.

Once everything’s planned out, it’s CNC time again. Frank cuts out the body outline, neck pocket, and the trapezoid F-holes. Then it’s a mix of hand sanding and power tools to get that neck just how we like it. Oh, and those f holes? We’re going for trapezoids of different sizes – gotta keep things interesting.

Next step: gluing that neck into the pocket with some old-school hide glue. It’s got great tonal transfer and can be taken apart later if needed. Then it’s onto hand-carving that neck-body transition.

For the custom-made bridge, Frank uses brass for definition and Ebony for tonal transfer and that warm, woody sound.

BTW, for tunes, Frank went with Hipshot Ultralights with a D Tuner on the low B. This way I can drop to a low A which is a wonderful tone particularly if you are doing any demolition around your house! 

Now it’s time for the side dots. Typically, on most basses, these dots sit right in the middle of the frets. But with this bass, they’re placed around the 1st, 3rd, 5th, 7th, 9th, and 12th frets.

Frank’s got his pickup hookup. Since the pickup he was building wasn’t ready, he popped in a Nordstrand blade to give it a whirl.

It sounded good, but I was itching for that single-coil vibe! And speaking of pickups, Frank showed me the Holly cover he was cutting to match, along with all the pink wire – talk about attention to detail!

A couple of things, while it is important for me to go passive, it is equally important for me to just go with a volume knob. Tone knobs are really just low-pass filters and the less in the way of a pure sound for me, the better. 

Finally, it’s string time! As usual, I went for the DR Pink Neon strings. Hey, I even have matching pink Cons…Both low tops and high!

Once we’ve got everything tuned up and settled, we’ll give it a day or two and then tweak that truss rod as needed. And voila, we’ve got ourselves a custom-made bass ready to rock and roll.

I want to thank Frank Brocklehurst for creating this 6 string beast for me.