Replies to This Discussion

Permalink Reply by Chris Carlson on December 9, 2013 at 10:00am

I've been the piezo route on my earliest builds - but was disappointed with feedback through the amp. You so much as touch your cigar box - you hear it amplified ten fold! If you want a cheap but very effective magnetic pickup from Gitty - get the prewired 4 pole P-Bass pickup with volume control. I think they sell for $13 or just buy that pickup alone and wire it directly to the jack yourself for $6.

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Permalink Reply by John Sawyer on December 9, 2013 at 10:54am

I've used pezos successfully in 10 builds, and yes, some installs work better than others.

Cons: 

Feedback is easy to do

Sensitive to anything hitting the box

High-impedance: works better with a preamp/booster or pedal effect.

 

Feedback:  If you just glue down a piezo, the box resonance can, under high gain, start to spontaneously feedback...   How you mount the pickup is key to a successful build.

Somebody recommend a good glob of hot melt, followed by covering the piezo disc in hot melt glue.  This dampens some of the high frequency vibrations.  By gluing the disc to the box lid, near the bridge, you can ensure you're getting the best sound.

Somebody here (sorry, don't recall who) has a flat plate that has a cavity.  The piezo is glued in that cavity, and the plate (opening side down) goes on the CBG, with the bridge on top.  This, theoretically, reduces the resonance of the box as an issue, and gets as much string vibration as possible.

 

Me?  I've used hot melt, and double-stick foam tape.  My favorite CBG uses both:  The disc is glued (brass side to the top) with hot-melt.  A good thick (~1/8") layer of hot melt was put on the underside of the lid, and the piezo sunk into it.  Over the piezo, I placed a piece of double-stick foam tape, ensuring the entire piezo is covered.

Works good enough for me, but like CC said below, my next build will be using a 4-pole P-Bass pickup....  we'll see how it works...

 

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Permalink Reply by John Sawyer on December 9, 2013 at 4:14pm

I have done that too, and they sound good. My only worry was the foam tape falling off the wood...

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Permalink Reply by Uncle John on December 9, 2013 at 2:13pm

John is spot on.   Chris is right too.   Piezos can work well.  Part of the answer to your question is purely appearance.   Do you want a guitar that looks like it came out of the 1930s?   Then a piezo is the way to go.

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Permalink Reply by Thomas "Duck" Petry on December 9, 2013 at 7:41pm

I've done Piezos with good results by gluing them into a piece of 1/4" oak. I make a recess to fit the piezo with a fostner bit and glue the piezo in with silicone sealer, then after it sets up I fill the cavity and scrape it flush with the surface. A notch in the top side holds the bolt for the bridge in place. It works equally as well for single or double piezos.

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Permalink Reply by jawbone on December 10, 2013 at 2:15am

I must admit - when I first saw this - I thought it was a little "Googly eyed character" !!!!
When I used this approach I cut the sides off to get a slimmer bridge, but that was a 27mm.

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Permalink Reply by Richey Kay on December 9, 2013 at 9:30pm

My latest build has the piezo wrapped in a piece of an old mouse mat. Seems to work really well!

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Permalink Reply by Brendan deVallance on December 10, 2013 at 3:19am

The Piezo element isn't so much of a pick up as a cheap ass microphone. So it picks up a lot of noise from the guitar body. And it can scream like a banshee with feedback. I have been encasing my piezo not in glue and wood, but in simple foam rubber. It lets you mess with it with out harming the element. And you can easily reposition it inside the guitar. I don't even glue the element in place, just cut a piece as wide (slightly wider) as the guitar box cavity. And I cut a small recess to hold the element. Close the lid on the cigar box and it is held in place.

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