Piezo Pickup Installation

[cygnus4001]

OK, first a plug for my bass builder then a question about installing a piezo pickup in it.

 

My new Wishbass arrived today, a definite A+!!! Now I know that folks either love em or hate em but I got a solid, well constructed bass that felt almost as good in my hands as my sweetie does, a smoooooth finish and every curve fits my hand like it was built just for me to fondle, I mean play with, oops I forgot if I was talkin about my girl or my bass, don't matter they're both hot. I love being a musician!!

 

Anyway, no pics yet to show but if you look on his website, http://www.wishbass.com/ and go to the Gallery Two page you'll see a Swirl bass on display. I had him build a headless, fretless 5 string version with no electronics, routing, etc, just the neck, body and the headless parts (tuners, bridge and the neck end cap). I went this route partly because I did not care for the upright style headstock and felt the pickup and volume knob/output jack plate looked very out of place on an otherwise funky body.

 

I can't say enough good stuff about it, Thanks Wish!

 

So after that shameless plug, here's the real question.

 

I want to install a piezo pickup under the bridge/saddle assembly. I have seen two different styles of piezo transducers and would like some input into as to which type I should be using.

 

Should I use a strip style transducer, about an 1/8th inch by an 1/8th inch by about 3 inches in length or...

Should I use one or more round ones about the size of a quarter?

[Bob Gollihur]

It's hard to see the bridge in the photo.

 

From others it seems that the bridge is simply a hunk of plastic or some material held in place against the body by the force of the strings, not glued or anything- is that the case??

 

More info and I'll be glad to make a recommendation or two based on my own experience with piezos.

[cygnus4001]

I got the bridge n stuff from Allparts.com, specifically part number BB_0343-010 and there is an accompanying photo of the part there.

It's a flat, metal saddle assembly that screws down solid against the body.

Lookin forward to your thoughts,

Thanks,

D

[Bob Gollihur]

You probably won't be able to use a strip or disc piezos with that conventional electric guitar bridge. The design does not appear to have "Fender style" saddles, so replacement saddles from makers like GraphTech won't work, either.

[cygnus4001]

Well darn...

 

It all seemed so easy in my head. Any specific reasons about why I can't rout a groove or circle under the whole saddle assembly and squish the piezo element under it when I screw the saddle part back down, wouldn't that provide the transducer with a good shot of string vibes?

 

Any good reading suggestions on the topic?

 

Thanks again for the replies,

D

[dave251]

I use a piezo disc in my bridges....but there is some geometry involved....the bridge has to be tall enough, and made from the right materials...specifically quartersawn maple. The metal bridge might work, but more than likely you'll have a hot string or two.

 

There are small piezo discs available from Mouser Electronics(www.mouser.com) but you'll still need to make room for a preamp.

 

My design does away with the preamp by routing the piezo signal through a magnetic string pickup, which is of course, more complex too...

 

So anyway, you might try four small piezos(or five, whatever the case may be) and place them DIRECTLY under the saddles between the bridge plate and body. Wire them in parallel. The issue here is "crosstalk" between the piezos; phase response becomes an issue unless there is good isolation string to string. The more parts you add, the more complex the problems and solutions become.

 

Here's a close up photo of my bridge design, on a guitar. If you look closely you'll see the modified piezo a quarter inch off the top of the guitar..it appears as a thin gold line. The second photo is one of my basses.

 

http://www.electrocoustic.com/newimage/bridge%20piezo.jpg

 

http://www.electrocoustic.com/newimage/Wenbobsbasslozsmall.jpg

[Bob Gollihur]

You could, I was expecting that you were using his bridge and was going to recommend a pair of transducers between it and the body. See my EURB bridge/transducer arrangement at http://www.eclecticbass.com/eurb.html

 

I have not done anything similar with a metal bridge; I would be concerned that the sound might be harsh as metal does nothing to mellow the sound of the strings, as wood does, and body noise could be a problem.

 

Good luck with your project.

[Tenstrum]

Please excuse my ignorance, but how does a piezo pickup affect the tone? Is it only meant to boost the signal of certain strings?

[davio]

I seem to remember a piezo in the bridge of an old Ergodyne model that I don't think they make anymore (either the EDA or EDC). Anyway, it was a metal bridge (I'm not sure what kind of metal) and I thought it sounded great.