It is known R4=R5=1.2k. My task is to calculate amplitude of oscillations at v0: Opamps and diodes are ideal. I did analysis of circuit without amplitude stabilization and I got oscillation frequency, but I cant figure out how diodes stabilize amplitude in this circuit. Any sugestion? Thanks in advance. Edit: I simulated this circuit in Multisim: It looks like amplitude is 8.954*sqrt(2)V. One strange thing: how can voltage on diode be 3.409V ?? I was thought that when diode is direct biased, voltage drop on it is about 0.7V.