The circuit was designed to create a line preamplifier by acquiring the use of double triode tubes. The circuit comprises of three parts, the main preamplifier circuit with tubes, the input selector ...

When most people think of tube circuits, the first thing that comes to mind is often the use of high-voltage power supplies. It wasn’t a given for tube circuits, though, as a range of low-voltage ...

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.

I recently had the opportunity to build a lavalliere microphone. The goal is to have a lavalliere microphone drive a small audio amplifier with an appropriate signal level. Technically, the lavalliere ...