Piezo pickups are definitely useful, but they have one really serious problem: Impedance matching. Having an impedance mismatch is like having your car in the wrong gear, and piezos really need to see a very high input impedance to sound good. If a piezo has to drive a low impedance the sound will lose a lot of low end and also sound bad in the mids and highs. There are a variety of good “acoustic” preamps available to help with this, including built-in electronics and floor units. Trouble is, they’re expensive and usually include EQ and effects you may not need. Not all piezo pickups need this kind of buffer, but I’ve run across a decent number that do.
Often enough I’ve done sound for musicians with just this problem, so I finally ended up building a few very simple, very cheap buffer boxes that I could carry in my bag and even sell cheaply if a musician wanted to have one. It runs off a 9 volt battery, uses a single FET (field effect transistor) and a few other parts, and can be mounted inside one of those little tin mint boxes.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell with Google Hangouts On-Air is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.
