how to build piezo pickups

Ray Diorec · From: Honolulu, Hawaii, USA

Hi does anyone know how to build piezo crystal pickups for acoustic guitars.

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Well, I've never built piezo guitar pickups, but I have worked with the piezo transducing elements, which are used in sonar systems. Basically, (when used as transducers), they're crystals that generate a voltage when stressed. That voltage is analog, and can be amplified in the same way as a conventional magnetic pickup. They do have some drawbacks, however. They tend to be fragile, and are susceptible to severe shocks, which can crack them. They also must be very carefully designed (read "thin") to respond smoothly to high frequency signals. All you would have to do to build a pickup would be to fasten two wires onto a piece of crystal (military applications use crystals which are electro-deposited with silver, but you could use conductive silver-epoxy, as well). Then, you'll have to prepare a mounting...that is, you design it in such a way that it is protected, but so the vibrations will flex the element. In a crystal phono cartridge, the crystal is fixed-mounted at one end, and the needle is mounted on the other end. It flexes the crystal in proportion to the record groove, and a small signal is generated.

It might be interesting to play around with, but you are going to have to spend an awful lot of time refining the design (size, shape, mount design, and placement) to come up with anything like an acceptable frequency response curve.

It's much more involved (and probably less "linear" and reliable) than the typical magnetic pickup. I'm not trying to discourage you, but just informing you as to the amount of time it will probably take to come up with something practical.

[This message was edited by Donny Hinson on 11 February 2003 at 08:09 PM.]

Tom Olson · From: Spokane, WA

Also, I might be mistaken, but the piezo pickups will only pickup the vibration of the string and that's it. In other words, for an acoustic guitar, the piezo pickup won't really capture the full sound of the acoustic as will a pickup designed especially for an acoustic. Like I said, I could be wrong. And, maybe the pure string sound is what you're looking for anyway. Just a thought.

Gino Iorfida · From: Pittsburgh, Pennsylvania, USA

If you are looking at the contact type pickup (not the individual string types, but rather the ones you place on the soundboard etc), you can build one yourself REAL cheaply. Get one of them piezo buzzer elements from radio shack, or pull one out of an old junked kids toy, 'talking' watch etc', and solder one wire to the center piece and one to the side, and there ya go... simple as it gets...

Ray Diorec · From: Honolulu, Hawaii, USA

Thanks guys for the info

Wayne Carver · From: Martinez, Georgia, USA

I made about five of these. They work as good as well as piezo pickups work. They work better for dulcimers, mandolins, strumsticks, etc. I used a thin layer of sticky putty to attach them to the body. You just have to expierment where to place them. Usually works better around the bridge. If you can attach a ground to one of the strings helps cut down on buzz.You could use an alligator clip. The sound is kinda trebley. I small preamp is recommended. I bought the buzzers from Radio Shack. I didn't try to cut them to different sizes. After you solder the wires on fill the plastic buzzer cover with epoxy and use it for a cover for your pickup. Heatshrink looks nice over the wires at the pickup and jack ends. There is info at Harmony Central's web site. harmonycentral.com
Do a search on homemade piezo pickup. The article tells you which buzzer to purchase.

Ray Diorec · From: Honolulu, Hawaii, USA

Thanks for the info Wayne i'll do a search on that.

Ray Diorec · From: Honolulu, Hawaii, USA

I found alot of info when I searched for the pickup making.They all pretty much used the same things to build one seems pretty easy to build I gonna try and tell you how it works.I'm making it for one of those 3 or 4 string stick basses maybe you guys have seen someone selling one online under stick bass. Well I play lap steel in a small group we play mostly hawaiian music and the bass player asked if I could make one of those cause the price was kinda steap for a stick with strings so I said yeah what the heck I'll try but I can't figure what he's using for his pickup he says peizo pickup? you guys got any sugestions.

Thanks
Ray

Ray Diorec · From: Honolulu, Hawaii, USA

I found alot of info when I searched for the pickup making.They all pretty much used the same things to build one seems pretty easy to build I gonna try and tell you how it works.I'm making it for one of those 3 or 4 string stick basses maybe you guys have seen someone selling one online under walkingstick bass. Well I play lap steel in a small group we play mostly hawaiian music and the bass player asked if I could make one of those cause the price was kinda steap for a stick with strings so I said yeah what the heck I'll try but I can't figure what he's using for his pickup he says peizo pickup? you guys got any sugestions.

Thanks
Ray

Bruce Derr · From: Lee, New Hampshire, USA

http://web.mit.edu/kumpf/www/Acoustics/main.html

Anybody ever put a homemade piezo on a Dobro? If so, how did it work out?

Wayne Carver · From: Martinez, Georgia, USA

I put one on a homemade resonator steel. It sounded better on the biscuit bridge. I don't know about a spider type. My reso/steel also had a regular electric guitar pickup. Each had their own jack. I plugged the piezo into an acoustic amp and the electric into a regular amp. It's like having two different instruments. Since piezos pick up high tones I was able to get mids & lows with the regular pickup.

Ray Diorec · From: Honolulu, Hawaii, USA

I finished making the piezo pickup and tried it on a Ukulele that I had made "Wow" pretty good for a cheap pickup very strong not bad for something less than 2 bucks.
Wayne about that biscuit bridge you put your pickup directly under it right? I dont have a guitar like that so can you give me the thickness of your biscuit bridge and what type of wood is it made of?

Thanks
Ray

Wayne Carver · From: Martinez, Georgia, USA

I placed my pickup on top of the bridge but on Dennis Havlena's website, below: http://www.ehhs.cmich.edu/~dhavlena/
he made a Doodle bass and placed his under the bridge. That would be a good experiement.One guy said he had better luck with his piezos using double sticky thin foam tape for just sticking it to the body of an instrument. I made my biscuit bridge out of oak but real ones are made of maple i think. You can go to stewmac.com and buy one cheap. They also will send you a nice catalog.

Ray Diorec · From: Honolulu, Hawaii, USA

Wayne the pickup is very strong and it picks up the sound from everything.When I stick it to a guitar I just touch the guitar neck and it picks up the sound what do I have to do to eliminate all those unwanted noise.

Thanks
Ray

Wayne Carver · From: Martinez, Georgia, USA

If it's a hum you will need to ground it to the strings or bridge. I did notice that the cord rubbing against anything up close to the pickup would make noise. Just make sure the cord is secured somehow. Maybe a piece of foam tape wrapped around the first 8" of the cord. If you run it through a small preamp with controls you can tune out some of the highs and make it less sensitive. I read somewhere about placing a resister or capacitor on it somehow to make it less sensitive. If I can find that info i'll post it.

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