Re: Piezo pickups and distortion

Mike Rivers wrote:

Actually, they put out quite a high voltage - piezo transducers are used
to make a the spark in cigarette and fireplace lighters,

They *can* put out high voltages.

In lighters, the piezo elements are hit by a tiny spring-loaded
hammer. The force on the crystal is huge, and very sudden.

I think my previous comments need to be clarified (really: corrected).
Years ago I experimented with using piezo transducers in my electric
guitars. I had really good results with that.

But that was on electric, not acoustic, which is what this
thread is supposed to be about. I failed to take into account
that acoustic guitar bodies vibrate a _lot_ more than those
in solid-body electrics. So I assume the problem with 'quack'
is magnified, along with output voltage. My bad.

unlike a magnetic
pickup, the piezo pickup itself is insensitive to magnetic fields.

Yes, exactly. One of the things I liked about using piezo
transducers is that with shielding, they can be very insensitive
to EMF.

The way piezo transducers function is not all that unlike the elements
in capacitor microphones do.

Not really. A piezoelecttric transducer generates a voltage when it's
deformed. A condenser mic changes capacitance, which results in a change
in the voltage between two electrically charged plates.

That change in voltage is also caused by a deformation. A
different sort, not using quartz. ;-)

A condenser
microphone depends on a source of charge to generate a change in
voltage. The piezoelectric element IS the source of the voltage.

Yes, that is it. In my mind, the two are a lot more similar
than different, but it depends on how you choose to look at it.

Jenn gave a good description of "quack" for the characteristic of a
piezo guitar pickup, but they actually work fairly well on instruments
that don't have a lot of low end, like the ukulele.

Well, take my above comments into consideration before following
up on this -- when I was experimenting with my electric
guitars, I found I generally got better sound by using smaller
piezo transducers. It might be that the smaller ones pick up
less low frequencies.


Jay Ts
--
To contact me, use this web page:
http://www.jayts.com/contact.php
.

Relevant Pages

  • Re: Ultrasonic Drill Suggestions Needed
    ... Many industrial piezo devices typically run at high voltages, which makes the amp design a problem even if you are a pro. ... The suggestion of the horn tweeter appeals to me. ... a cursory glance at simple voltage multipliers gives a few questions: ...
    (sci.electronics.basics)
  • Re: Single-supply piezo-preamp circuit for e-guitar
    ... >I think your way too high there on your assumption, I've fed Piezo guitar ... the voltage swings under control (and at the same time, ... My new piezo buffer runs fine on 3 AA cells for ... Tony ...
    (sci.electronics.design)
  • Re: piezo nut
    ... why not a routed groove in the neck ... set-ups that you and Derek are describing is that piezo transducers ... Piezo transducers such as the ... Derek Tearne - derek@xxxxxxxxx ...
    (alt.guitar.bass)
  • Re: microwave oven - beeper too loud
    ... > What piezo speaker inside a PC? ... piezo transducers on the motherboard instead of the regular little ... speaker that most machines have. ...
    (sci.electronics.repair)