I am running into a problem trying to set up a Wien Bridge oscillator on a breadboard.
It works well in the simulation:

[![enter image description here](https://i.stack.imgur.com/2jPsZ.png)](https://i.stack.imgur.com/2jPsZ.png)

In practice, though, I get this waveform:

[![enter image description here](https://i.stack.imgur.com/YpouQ.jpg)](https://i.stack.imgur.com/YpouQ.jpg)

Does anyone have an idea what could cause this?