In my piezo preamp tutorial video, I showed you how I built my own piezo preamp for my cigar box guitar, and, I tested the preamp on a few electric guitar effects pedals. I reported that my preamp sounded good, but produced a soft hum, and that my TC Helicon Play Electric's e-guitar FX didn't work well with the preamp. I was TOTALLY WRONG about both issues. After repairing my preamp, I learned that it produces a completely clean sound and that it works pretty well with the TC Helicon play electric. Check out this video for more details: