Replies to This Discussion

Permalink Reply by Tom "Broken E String" Sobieski on September 9, 2012 at 11:29pm

I've used silicon adhesive and even hot glue and both work well. The trick with a piezo disc is to reduce the physical contact with the CBG body as much as possible. This allows the pu to function as a mike and not pick up vibrations from fingers and so on.

I've not used them , but it's been said thatb with a piezo ROD, you need contact.

Permalink Reply by Wes "I'm Baaaaack" Yates on September 10, 2012 at 1:20am

My best suggestion is to encase the piezo(s) in hot glue from a hot glue gun. I usually make them by putting a small dab of hot glue in between two piezos and press together until about 1/32" gap OR when the hot glue comes to the edge. Let cool. Place a dime size glob onto whatever I need to mount on or into what pocket I want to place the piezo in and press the piezos into that. Let cool. Apply more hot glue to the top/sides completely covering the assembly. while still hot, I will flatten out the top of the hot glue.

Usually I make them in a bottle cap.

-WY

Permalink Reply by PhilUSAFRet on September 10, 2012 at 1:38am

Hmmmm, similar to a  Schatten Dualie.....if it sounds like one, Shazam...home run.

Permalink Reply by Rand Moore on September 29, 2012 at 2:39pm

Hi Wes,

I've tried your method with putting the piezo between two layers of hot glue within a bottle cap, except that I hot glued the top of the bottle cap piezo pup to the underside of my sound board. The results were good -- it isolated the finger and handling noise that plagued my earlier attempts. However, it also seems to have attenuated the treble side of the spectrum producing an instrument that is too bass-y IMHO. My two bottle cap piezo builds (one a CBG and the other a paddle box dulcimer) both use wood sound boxes, and to get decent volume I have to turn my amp way up and turn down the bass and mid range to get much treble. Turning the amp that high however, makes it hum. So, I'm looking for suggestions on how to isolate without filtering the high and mid-range frequencies. A couple ideas include using less hot glue, using a piezo built into the bridge instead of attaching it to the sound board, and perhaps using wood with silicon seal, or double sided tape with silicon seal as Colin McGrath suggests. But I'm interested in knowing which method provides good isolation but w/o reducing the high- and mid-range frequencies. The bottle cap / hot glue method seems to offer excellent isolation, but is better suited to instruments like canjos, cookie-tin banjos and oil can guitars which tend to have too much treble to begin with.

-Rand.

Permalink Reply by colin mcgrath on September 10, 2012 at 2:38am

I have used thick double sticky tape to attach to the lid then cover with silicone caulk. I had no feedback with that. I use a Crate vintage 20 amp.

Permalink Reply by Keith Stanford on September 10, 2012 at 3:48am

Like others mention on here, I too found that using Hot Glue to stick the Piezo Disc to the box, then putting a glob of Hot Glue on top of it really helps to get rid of any 'tinny' sound. It does, however, muffle the sound somewhat where the Amp Volume needs to be turned up a bit.  The biggest benefit that I see to the Hot Glue technique is that I got NO unwanted sound of my hand running up and down the CBG Neck, and NO sound from my strumming hand hitting the box.

kieta

Permalink Reply by Wes "I'm Baaaaack" Yates on September 12, 2012 at 8:57am

I don't glue the piezo(s) onto the lid as it contributes to feedback in my opinion. Think of the lid as one big eardrum. I embed them into a recess on the underside of the bridge -- assuming I make one. Else it is what it is.

-WY

Permalink Reply by Keith Stanford on December 14, 2012 at 5:45pm

After more experimenting with Piezo (discs) here is my final results.

A single piezo taped to the CigarBox was tinny and picked up the sound of my hand rubbing up-and-down the CBG neck. (Sounded like a hissing sound.)

A single piezo 'hot-glued' to the CigarBox got rid of that tinny sound, and also got rid of that "hand-on-CBGneck hissing" sound.  BUT....a lot of volume was gone!  Also, lost that traditional CBG sound.

So I wired both piezos in parallel (one taped to the CigarBox and one hot-glued to the CigarBox) and got a great sounding CBG!  The sound is 'full' and though the "hand-on-CBGneck hissing" sound is still present, it is 'masked' by the richer sound of the hot-glued piezo.  I am pleased with this sound, as it seems to have gotten the 'best-of-both-worlds'.

(Side note: The best sound was by turning the Bass all the way up on the amp, and turn down the treble.)

Now I will be experimenting with Rods, humbuckers, wall-worts, etc

Stay tuned....

kieta

Permalink Reply by PhilUSAFRet on September 12, 2012 at 11:07am

I see wes, appears to be the piezo disc equivalent of an undersaddle piezo strip.  Makes sense.  Thanks

 

Permalink Reply by SD Helfrich on September 28, 2012 at 7:12pm

I have a question about this as well...

I saw someone (probably somewhere on Youtube) had started making bridge kits, which consisted of a block of 1x3 with a compartment drilled into it for the piezo. The piezo was glued or siliconed inside the block, and a hole drilled into the cigar box to run the wires through. Then the block was set in place and a small brass rod was then placed on the block for the strings to rest on. As I understand this set up, the piezo picks up the vibrations from the block of wood under the brass rod rather than the guitar body.

Has anyone tried this, and does it work better than having piezos inside the body?

-SD-

Permalink Reply by ROBERT GREGORY on January 21, 2013 at 5:06am

I have had some fun experimenting with piezo's and one method that I am using now is to sandwich a piezo between two pieces of wood , as others have mentioned.One difference being that  I fill the middle of the sandwich with silicone. So the piezo is encased in silicone and sandwiched between thin pieces of wood.Volume is reduced, but the sound is full and the handling noise is greatly reduced.

I experiment with the placement, as every box seems to be different. The best sound has come from adding another naked piezo wired in parallel. That one I just clue to the neck, right under the bridge and the encased I have found works well attached directly under the lid where it can pick up more vibration.

I find that I get my best sound with a humbucker. But piezos are a lot cheaper...