Balanced Low Noise Microphone Preamp: very low noise, close to the theoretical minimum, high hum rejection and variable gain with a single rotary pot, similar to that used in many professional grade mixing desks
Low Noise Balanced Microphone Preamp: very low noise, close to the theoretical minimum, high hum rejection and variable gain with a single rotary pot, similar to that used in many professional grade mixing desks
SIMPLE AUDIO PREAMP: This easy to build circuit provides good gain to weak audio signals. Use it in the front end of a RF oscillator to make an RF transmitter that is very sensitive to sound.