I have built quite a few CBGs with disc piezo pick ups in them, a few with a magnetic/ piezo combination. I have been happy enough with the clean acoustic sound using a piezo along with a pot for volume control. I knew there were ways to get better sound with piezos and built a JFET preamp for one of my builds. The preamp worked fine and certainly improved the sound quality along with the volume.
I have seen many acoustic guitars with a preamp installed in the body. I thought this would be a good way to get better quality amplified sound from a CBG while keeping that acoustic tone. It took some searching but I found an acoustic guitar preamp with a flat mount instead of the normal curved mount. A JOYO JE 307 is what I found. It has more features than I was expecting, 4 tone controls and a tuner. I would have been happy with just volume and a tone control.
The onboard tuner is going to be handy.
The flat mounting surface needed for mounting in a cigar box.
It is hinged for easy replacement of the 9 volt battery.
I had done some trading with another builder I know through the Internet and got a nice deep, Romeo Julieta box. He seemed a bit surprised at my choice but I had done a build with a similar box and really liked the sound.
A nice simple box.
A hole cut to mount the preamp in.
A test fit. Looking good.
The box was sturdy enough but I wanted to be able to screw the lid closed. I added some blocks in the corners. I needed a way to hold the blocks in place while the glue dried and couldn't get clamps on the corners on the lid side. Bamboo skewers put just the right amount of pressure on the blocks while the glue dried.
With the fret slots cut in the Poplar fretboard and the fretboard glued to the Poplar neck, it is ready for fret markers. I normally don't put fret markers on the fretboard, but they do give the CBG a more finished look.
I used some scrap Mahogany for the fret markers. With a couple coats of shellac and the light hitting them just right they look like copper.
Frets and tuners installed. This is my first time using a zero fret.
Everything screwed together fine. I'm using a single sound hole on this build.
Copper nails for side markers.
I decided to mount the rod piezo under the bridge, inside the box. I used a piece of wood with a channel in it to clamp the pickup to the lid.
This worked, but the volume was a lot lower than in my initial test where I put the pickup between the bridge and lid.
Time to try something else....
I routed a channel in the bottom of the bridge, just deep enough for the piezo.
I drilled two holes under where the bridge mounts and threaded the piezo through those holes. With the bridge sitting on top of the piezo and strung up the volume increased a lot. Success!
A couple pics of the finished CBG.
A couple videos, the first is unplugged and the second is played through a Crate Profiler series practice amp using a clean profile.
