Hi there

I just installed piezo in a good acoustic guitar. I installed inside the guitar, under saddle. But the sound i am getting is like a microphonic pickup(very loud humming). It is very noisy. Just pickup which not potted in wax.

Last time when i faced similar problem in a diy pickup(magnet and coil one), i potted in hot wax.

So wats wrong?

Do i need a preamp?
Quote by billm90
more details.

which pickup?
what are you plugging it into?
how did you wire it?

No you dont pot piezos in wax. they dont have coil wire that vibrates. it would nothing for you.

my guess knowing nothing about what you have going on..... I am guessing you plugged it into a guitar amp directly and it sounds terrible?

you may need a preamp to fix this due to the output of the piezo. it is not like a magentic coil.

Just ordinary piezo directly solded to jack and connected guitar amp.

Just noise, look like bad earthing. Touching any metal on amp reduce it e.g. screws or bare pots of tone and volume.

Also can u suggest any preamp schematic
You might want to cheack if the solder points are in the right place cause that could be a big issue. mine buzzed real lound till I found its sweet spot......and also you could have wired it the wrong way......no you don't need a pre amp cause the Pizo on my cheap Johnson dosn't even have a volume and its just fine.
Hearing about a pair of great boobs is like hearing about a really cool bug or lizard as a kid and you just gotta see it.
What you are hearing is AC HUM floating from the mains around you. To get rid of the HUM you need to use a single core wire with a screen and solder the screen to the outside of the piezo and the remaining wire to the top part of the piezo. Use thin wire as not to inhibit the vibration too much of the piezo. Keep cable as short as possible to your preamp. You will need one for a piezo pickup as the piezo posses a high impedance and is prone to pickup noise. Especially AC hum. Search for my thread: 'diy guitar pickup' you will find a preamp circuit.