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Piezo Secrets from Cigar Box Nation Members

Your Favorite Piezo Tips & Tricks!

Piezo Tip: "Like a Stomp Box in Your Hands..." With Four Piezos

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.

How to wire it up:

Twist 2 black wires together + the other two black wires together.
Then twist those two doubles together to make all 4 black wires into 1 well connected twist/current.
Then loop on jack + solder - 1 solder easier than multi.
Repeat for red wires.
Hot glue gun to put piezos in place.

Piezos under bridge for strings, and at sides for percussion. Piezos work well in lighter woods, multiple piezos (even fine for small ones), and simple circuits.

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.

Piezo Tip: Hot Glue Reduces Feedback

by RayTheOtherRay

I use hot glue to attach the piezo disks to the box top. Hot glue between the disk and the box does not completely remove handling noise while playing, but does mitigate it to a degree. Once wired, I encase the remaining visible part of the disks in hot glue to reduce open air feedback.

Piezo Tip: Felt Reduces Feedback

Name: Bill Farley

What's your piezo tip?: I had built a bottle cap piezo pickup, and it kept feeding back. I cut a piece of felt and glued it to the bottlecap pickup, and then added a piece of foam from there to the back side of the guitar. This eliminated the extreme feedback issue on my guitar.

Piezo Tip: Silicone Caulk Reduces Feedback

Name: Mike Scott
:
Be sure to cover the backside of the Piezo with silicone caulk or plasta seal to keep any ambient noise or vibrations down. Cover very well!

Piezo Tip: Mounting placement - Finding the sweet spot

...plus the Tillman pre-amp circuit

by Glenn Reither

I mount mine very slightly forward of the bridge and a bit toward the lower-pitched strings. I don't put anything between them and the top, because why reduce the amount of information they get?

I prefer in-box piezos to under bridge rods because

they are easier to install and
I like the different characters that different boxes give.

I use tape to stick them on temporarily until I find a good sweet spot. I used a circle cutting drill blade to cut a bunch of circles out of 2-ply that are slightly larger in diameter than the piezo (I find the larger piezo discs sound better). The piezo gets glued to the top of the box, I run a bead of hot glue around the outside, put the 2-ply cover on top, and seal it all off with hot glue. This reduces feedback and handling noise without choking the piezo.

I hand build the Tillman preamp circuit (below) and often put a Twin T notch filter in line on a switch so I can knock off the pokey high frequencies that make overdriven amp settings sound awful.

I did come up with a passive tone adjust that works, but piezos sound so much better through a preamp that I only used it once.

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Replies to This Discussion

Permalink Reply by Slow Slough Guitars on November 6, 2015 at 2:54pm

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

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Permalink Reply by BP - RabidSalad - on March 19, 2016 at 3:30am

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.

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Permalink Reply by Uncle John on March 20, 2016 at 9:19am

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.

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Permalink Reply by Russ Oakes on October 21, 2016 at 1:33pm

I have used thin closed cell foam, this also seems to help "movement" noises

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Permalink Reply by John Sawyer on October 22, 2016 at 2:29am

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!

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Permalink Reply by Dave Nyberg on October 10, 2019 at 5:42am

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.

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Permalink Reply by BrianQ. on October 10, 2019 at 7:20am

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!