Figure 9: Gain verification. Output is measured from a 10 μV input source as approximately 11, missing the design estimate of 12.5 by about 15%. The green arrow shows the 350 Hz −3 dB frequency. The upper 3 dB (not shown) is much greater than the signal range of interest (approximately 10 kHz). The curves show performance of variable in this configuration. Notice the gain has been stabilized to less than 3 dB across a threshold variation of 1volt.