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 ...

Over the years I’ve become a student of mic preamp design, building and modifying several along the way and learning a little more each time. Usually, I worked from a kit or published set of plans.

After some research I was able to find a relatively cheap solution to build a megaphone suitable for street demonstrations. A megaphone hardly needs an introduction but, a megaphone is a portable and ...