I am converting a small child's guitar to a bass. Using a passive internal piezo disc is simple and cheap. How well does this work? Adding controls/eq a lot more work, a little more expense. If I go passive, will I wish I'd have installed electronics? How well do the passive systems work? They seem to work well on my ukes, but require a pre-amp/eq with some amps. I have a Peavy 60W 12" amp.
I assume that you are using flubber strings. For all of my basses, even the steel string ones, I have used an active (9V battery powered) pre amp with a rod piezo under the saddle. The first one I built with weed whaker strings, I used a disc piezo direct to the 1/4" plug, but the sound was too low, so I put in the active preamp with the rod piezo and this corrected the problem. Have fun!
Actually, to reduce cost and tuning machine problems, I was going to use Elixr coated super light bass strings. This little guitar is pretty flimsy. Thinking of gluing a reinforcement plate under the bridge. As it is, I have to install an end black as there isn't any. Guess I'm going to have to use the pre-amp then. Thanks