Piezo disc components as pickups?!

Erlend_G

Erlend_G

New member
Hey,

I'm pondering on the idea; of getting some cheap 25mm (1") piezo disc components;
and gluing/taping them on the inside of my Epi Wildkat's top/lid. :)

In theory, they would translate any vibration into a (faint?) audio signal.

The parts are real cheap; though I need to know, if it will work or not...

looking for a subtle "addition of acoustic and other sound", not a hi-fi replication of my guitars sound :).

Thanks

-E ♪
 
I did something similar to amplify a 22 (nylon) string rosewood harp. The signal is very low volume, and very attack-y. It works, but needs boosting and EQ to sound more like the instrument sounds acoustically.
 
I have to agree with Dave. I have two instruments with active piezo that sound amazing. The passive piezo in my mandocello sounds thin and spiky. Blending it with the magnetic pickup does give some nice flavors, but it is fairly useless on its own.
 
The passive piezo in my mandocello sounds thin and spiky. Blending it with the magnetic pickup does give some nice flavors, but it is fairly useless on its own.
Click to expand...

You have a GoldTone?
 
Yep love it.
Click to expand...

I had one of the very first batch imported. I was very disappointed in the acoustic sound. It was far too quiet, and it played terribly stiff. That Zero Glide nut was a mile high. I rectified that, made a new bone nut and did a complete setup. The pickguard was mounted improperly and I had to change that. I hated the knobs, too - I replaced them with some modified knobs from a pedal so they weren't in the way so much. I thought that the piezo in the bridge sounded like crap, and I didn't like the way it was installed. I never did get it sounding good. But the kicker was that narrow neck - I just can't play toothpicks.

When they were being planned, I spoke to Wayne - the owner of GoldTone - at length, and he assured me it would be a terrific playing instrument and sound fantastic. And it wasn't. Within 3 weeks I sold it to another guy for about the same money I had in it (I got a good deal from the seller). I complained about it to Wayne, and he was disappointed I didn't like it. On the Mandolin Cafe, there was a long thread about them and I weighed in with my opinions. Wayne complained - had the thread deleted. I complained to Wayne and that got me banned. It was not a great experience, and soured me badly on GoldTone stuff.

Later - I bought a used Eastman Mandocello and I've been much happier. It's quite playable, sounds great acoustically or plugged in. and makes me much happier than the GoldTone. I guess the money was worth the difference.
 
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Another thought: Did anybody use a IR Loader with acoustic guitar IR (heard good things about a Martin Dreadnaught IR) on a piezo pickup?
 
hamerfan said:
Another thought: Did anybody use a IR Loader with acoustic guitar IR (heard good things about a Martin Dreadnaught IR) on a piezo pickup?
Click to expand...

I have, but I don't think it really improves it. A good acoustic with a good pickup is really the best thing. Using an IR makes a thinner version of the sound- the same basic tone with some EQ frequencies notched out. It generally isn't better, and at best, it is a sideways step.
 
John's-Pickup.jpg
I've been making three element piezo pickups for several years. 12mm discs are a good size for adhering to the bridge plate, just forward of the bridge pin and string ball, located between the 6th and 5th, 4th and 3rd, and 2nd and 1st (slightly closer to the 1st per K&K mini install instructions). The hard to find component is ultra light braid-shield coax.

The wire best I've found is here:
https://www.digikey.com/en/products/detail/molex-temp-flex/1000660053/4368702

It's expensive at $26.63 per 10'. But it's Belden Cable. The jacket is quite stiff and I remove it leaving just the braid shield wire.

The tricky part of assembly is learning to solder wire to the piezo element. The datasheet link here explains the proper method:
https://www.digikey.com/en/products/detail/pui-audio-inc/AB1290B/1464740

Last, there's a research paper somewhere in the ether that recommends adding mass to the piezo element to tame the harsh high-frequency characteristics of piezoelectrics. I use a drop of 5 minute epoxy to each piezo after the coax has been soldered in place. Epoxy will spread out forming a 1mm layer on the disc, adding mass and protecting the exposed strand core of the Belden.

My complaint with using K&K is their coax wire; each element has wire from it's piezo soldered to the endpin jack. Three lengths of the jacketed coax adds stiffness and weight to your guitar top plate. Adding extra weight and rigidity seems counterproductive, even if it's on a micro scale.
 
Occasionally it's necessary to remove and re-glue a bridge that's lifting.

That process involves removing your piezo pickup. Easy when it's an under-saddle, not so simple when it's a bridge plate pickup. Permanently installing a bridge plate piezo involves gluing the elements with either fish glue or cyanoacrylate (super glue). A single edge razor blade will most often pop the piezo discs free without damage, but once in a while the piezo will bend and it's toast.

I feel much better replacing a few $0.80 piezos than I do laying out $120 for a new K&K.
 
hamerfan said:
Another thought: Did anybody use a IR Loader with acoustic guitar IR (heard good things about a Martin Dreadnaught IR) on a piezo pickup?
Click to expand...

Not an IR but I did try the Fishman Aura Imaging Pedal with my piezo it didn't really give me much.
 
Mincer said:
I have, but I don't think it really improves it. A good acoustic with a good pickup is really the best thing. Using an IR makes a thinner version of the sound- the same basic tone with some EQ frequencies notched out. It generally isn't better, and at best, it is a sideways step.
Click to expand...

I respectfully disagree. Years ago I experimented using a Fishman Aura Spectrum DI. The IR's available through the Fishman archive are extensive and built using decent guitars and studio grade microphones, but they aren't your guitar. I was underwhelmed and sold that box years ago.

A few years ago I got a chance to work with bass player extraordinaire Carey Black who was using an Audio Sprockets ToneDexter DI for his bass fiddle. I bought one the next day, and have gigged with it ever since. The ToneDexter enables you to build IR's using your guitar and any mic you like. That being said, the better the mic the better the IR. My preference is a Neumann KM-184. Audio Sprockets has steadily improved their firmware and the latest version is excellent at eliminating the low freq 'wolf tone' that's common in live and loud settings.

Last summer I had opportunity to play the main stage at Red Ants Pants festival in Montana. FOH and monitor sound was top-notch and the sound of my guitar with home-made piezo through the ToneDexter was absolutely astounding. I'm on the left playing my Euphonon,

Red-Ants-Pants-Festival-2021-Main-Stage.jpg
 
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