Hi, have you considered an external pre amp? I often mount a guitar pre amp in to a small box that sits on top of the amp or on the floor.
Depends on the client's prefered tone they are looking for. I think you can make passive piezos to work. You might already know this, putting the piezo under the first strings will give a bassy sound. If placed under thinner strings, you'll get a brighter sound.
There is a diagram around here of installing a tone pot to piezos the correct way. You'll need a 100k resistor between the piezo output and the tone pot. There were more instructions but thats my memory. I think it was Brian Q's discovery, maybe he can chime in to clear things up.
Also, by word of mouth, I hear larger piezos are better.
Hi again, I did not answer your question fully as you made mention of saving the cost of a simple wiring task. The better quality the piezo element the better the sound/quality/output. This better quality comes at a cost. I use JJB electronic and K&K pickups and pre amps in my full acoustic builds, but these would be far too expensive for the simple CBG style guitar/uke.
The goal with acoustic pickups is to try to have the best acoustic sound from an acoustic instrument one can get when amplified, very hard to do I think with cheap equipment.
K&K recommend their larger size piezo's for larger instruments, 12 string guitar etc.
Do what Ill Green suggests and play with positioning, and I would also try different mounting methods, with nylon strings you should get a reasonable sound.
If you’re not trying to do any wiring, then try one of these little guys. Only 1 5/8” x 2 5/16” plus it comes with a rod piezo?
I tried suggesting a stand alone preamp like taff mentioned ,but the site was acting weird the other day? What was that?
Here’s a tutorial for the stand alone preamp