This mic preamp uses the low noise IC uA739. The circuit is an example of how a good preamplifier can be designed for dynamic microphones. The IC houses two identical integrated preamp circuits. The ...

Piezo discs have been around since the 1970s, and such cheap (and easy-to-handle) discs are widely used by avid electronic hobbyists and experimenting musicians all over the world. A piezo disk ...