Together with an electret microphone cartridge like Panasonic WM-60A, WM-61A or Monacor MCE-2000, MCE-2500 you get a very linear measurement microphone that can be directly connected to line in of your sound card. It is suitable for measuring speaker response or room response. The gain is +20 dB or +30 dB, depending on the setting of J1.
The amplifier will not work with the modifications to the microphone as suggested by Siegfreid Linkwitz to improve the high level linearity.
