Acxico 3Pcs AD828 Stereo Dynamic Microphone Preamplifier Board Pickup Module DC 3.8V-15V MIC Preamp Module

Nice sounding amplifier, used it in an acoustic guitar with a piezo sensor. Easy to change the gain by changing r5 for one channel, and r7 for the other.... gain is r5/r6, and r7/r8. Installed is 100k and 2.2k. Maintain the 2.2k and change the 100k. Has a voltage gain of 45, and a db gain of 33...

I ordered a tree peace set got one item twice. Seller gave me a refund. But the one peace I have doesn’t work. Yes put together correctly. I know electronics. So no money lost thanks to refund from seller. Thank you.

Only got 1 boardWorks fine though

Great sound when they work. Out of 9 purchased, several where noisy and 2 were dead.

I used these as a pizeo buffer/ preamp for my bass guitar build. They would also work for a guitar.I combined them with Fishman style pickups that use a 2.5mm plug to connect, so I had to do some creative wiring to make them work for my application.The wiring is straightforward, they are stereo, so one signal wire from a pair of pizeos goes to left (marked L) the other signal wire goes to right (marked R) and both ground wires are combined to the ground connector (marked G). If you're using this mono, you need to short the unused input to ground.On the output side, if you're not using stereo, you need to mix the channels which can be done with a 100K Ohm resistor wired to each output. If using them mono, only the input needs shorted to ground, do not short the unused output!The battery terminals are labeled + and G simple enough.You will want at most 23ga wire (and 26 is none too small) and a fineas the solder points are tiny!

It is probably a good product, but it is useless to me because there were no instructions or schematic with the product. A link to a schematic would be enough, but there is not even that. What am I supposed to do with this?

Did the job for making an electret mic amp. Added 10K pullup to +input at the pin.

Worked great to amplify a Piezoelectric microphone to usable level as input to audio amp.