Here is an Electret Condenser Microphone – ECM preamplifier circuit based on ultra low noise BC650C transistors. Due to difficulty of finding BC650C, instead of them, as you can see in the schematic, ...

This article originally appeared in the Feb. 8, 2017, edition of Radio World Engineering Extra and was posted on this website Feb. 9, 2017. If you like this content you should subscribe to Radio World ...

Fig. 1: Diagrams from Wente’s 1916 patent application show the condenser microphone in cutaway view. Diaphragm (#6), which is grounded, is stretched only 5/10000th of an inch from the backplate (#7), ...

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 ...