I have left last time with the first preamp project done, but in search for a better and powerful solution to amplify some piezos microphones_
I have decided to search on the internet for a good schematics to build one more-powerful preamp on my own.
I came across this site: breaksberlin.wordpress.com.
He’s a really kind guy that has shared an interesting article on how to build a really powerful preamp for your piezo mics. PERFECT.
I’ve bought all the components to do the circuit and I wanted to hazard with a dual channel version of it with separated power stages (9V battery) for each one.
I’ve told you that I’m not really into circuitry and so the only 2 comments under his post are mine (both of them a little dumb, I know, but hey, everyone needs to do mistakes before learning something).
END_2: After have soldered all of the parts and after a short testing period I can say that the project works perfectly and it reaches a maximum gain of +50db for each of the 2 channels.
There’s also a hi-pass filter really useful for the piezo application, two separate power switches with their own leds and I was able to put all in a relatively small aluminium box to be able to carry it with me in the future travels_
I’m really grateful to the guy of breaksberlin’s blog for the amazingly professional schematics of the circuit (you can find it here) and to my personal perseverance in insisting even if some things do not seem to work properly at the first try_
I introduce you to my "I'm not a bomb" project; here below a couple of pictures_