Designed a Sallen Key low pass filter using Analog Devices wizard. The output in Pspice the cutoff is way down from where it should be. Instead of the cut-off of 2.5Khz. We get a cut-off of around 900Hz. Just wondering if any ideas why Pspice is causing this problem. We have a gain of 100 so 10 on each op-amp. Even with unity gain the same problems occur. Design and output attached.