Jan 28, 2007 #1 E eyeow Junior Member level 1 Joined Jan 13, 2007 Messages 18 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,494 electret condenser microphone preamp actually i am doing a sound frequency meter. i have found my circuitry of frequency meter in microchip.com https://ww1.microchip.com/downloads/en/AppNotes/0037.pdf now, i would like to determine the input circuit, which is the ECM preamp with TTL output. the output have to match the input of frequency meter as i mentioned above. do u have any source / reference on ECM preamp circuitry with digital TTL output?
electret condenser microphone preamp actually i am doing a sound frequency meter. i have found my circuitry of frequency meter in microchip.com https://ww1.microchip.com/downloads/en/AppNotes/0037.pdf now, i would like to determine the input circuit, which is the ECM preamp with TTL output. the output have to match the input of frequency meter as i mentioned above. do u have any source / reference on ECM preamp circuitry with digital TTL output?