by Chick Who Tinkers
I use four small piezos straight to jack, no volume or tone. 2 on center under bridge, and one on each side. Super responsive and nice thump when tap it – hand flick makes for beat along with the string playing. Like having a stomp box in your hands while you play.
Piezo Tip: Reducing "Quackiness" with Capacitors & Resistors
Name: Kirk Bolas
I've experimented with different values of cheap ceramic capacitors and resistors (a basic passive RC network) in order to find a combination of the right values of each that shifts the resonance peak of the piezo' output. The goal was to have a signal the de-emphasized the quackiness of the pickup without making it sound tinny or muffled. The signal is modified before it's "massaged" by any other components. It's not perfect, but it's better than stock sound and cheaper than an expensive preamp. Each pickup is different as is every instrument that it's installed in.
Cable length can have an effect here too. I generally use a 20 ft. cable.
One must experiment with each combination for best results. There's no one-size-fits-all solution.
One that I did I recessed the piezo into the through neck and potted it in hot glue. That seemed to do a good job of keeping the squelch down
With disc piezos I tend to mount mine in silicon forward of the bridge and on the low string side.
With rod piezos i sandwich them between the neck and box top at the bridge point. I've done this with disc piezos as well and it works great too. With the rod piezos I cut a small channel where its to go thats not quite as deep as the rod is thick. Gets held in place with a piece of masking tape when closing everything up.
I think the best thing you can do is to coat the top of the piezo disc with hot melt glue. I think it reduces feedback and improves tone. Some call doing that 'sandwiching.' It may be the same as what Slow Sough Guitars means by 'potting'
Placement: best: under or near the neck. second best: on the neck.
I have used thin closed cell foam, this also seems to help "movement" noises
The tillman preamps work great, but so do regular acoustic preamps, and mounting them in a box, pedal style (as seen on CBN) is awesome. They're cheap and come with a Rod piezo.
I have also found that foam mounting tape works great on both sides of the piezo. Peel and stick!
I used a square of foam the size of the piezo and glue it to the back side of the piezo after installing it. It helps to reduce feedback.
Here’s a layout that will accommodate the “Tillman Preamp”, in fact, it’s a modified version of it? The layout shows it wired through the cbg’s volume pot, it can be omitted for a stand alone unit?
Please respect my work & do not Upload my layouts on Pinterest or any other sites without consent, this is only for us here at the Nation & would like to keep it that way. Thanx :) Enjoy!
may i ask why there are two volume pots? you are feeding the output of the first directly into the second in series.. One pot would do the same job..
Master volume effect