People Does anyone know why the ac701 is considered one of the best tubes for a condenser microphone? I have read what specs I could find on the web. I can understand why the grid wire exits the other side of the tube away from the other outputs. I also understand that the german Neumann microphones used the ac701 and the export models used the ef86. I have not heard the ac701 in a microphone I have heard ef86s in microphones.