Oktava MK-12
The Oktava M-12 Condenser microphone is a pretty good microphone in the lower price range for overhead microphones. Lot of information is available on the internet and this came in handy as one of the pair of microphones in my possession broke down. It did work, but a lot of noise was produced by the microphone. The circuit of the microphone is very clever to hide weaknesses in the components used. The used components are not that very high-quality, especially the large value resistors - as I found out…
During my quest to find the problem, a lot of interesting stuff became clear. So this was also an investigation in the way condensor microphones work (using phantom power)!