Question Passive Piezo High Impedance??

[WalterLacayo]

Hey there piezo people!.... I've got a question for you guys

I thought I knew what it was all about but now I'm confused so please enlighten me.

I know a passive piezo has high impedance, what does that really mean?
I've read I'll need an external preamp, no problem with that, but what I don't really get is what would happen if I didn't use it.. how would it sound?

Let's suppose I plug it directly into an amp, will it sound weak or what? (I'm thinking a keyboard amp I have stored without use at the moment before buying something that will do a better work)
Also read something about cable capacitance affecting the signal in some kind of way... how's that?

I need simple explanations.. mostly refering to how it will sound, how the sound signal itself will be affected, I undestand the technical lenguage almost entirely... but always leave with doubts.

Thanks!!!!!!

 

[brokenvail]

You can go straight into an acoustic amp. It by design has a preamp and a power amp built into it.

 

[beej]

Passive piezos generally don't sound very good into the front of an amp without a buffer/preamp.

In terms of electrical effects ... piezo pickups are high impedance. They will be affected by a long cable run, another reason that they're generally used with a preamp of some sort.

(It's tough to explain impedance without getting too technical. Basically, it represents the relationship between voltage and current which a device is capable of accepting or delivering.)

 

[WalterLacayo]

oh I see.. thanks for your answers!