Creating a variable wien bridge oscillator

[ARNAB MONDAL]

are you sure that i would directly connect the op amp output to the lm386 audio amp

 

[BobK]

No, I did not say that. The LM386 has a minimum gain of 10. You would probably need to reduce the output, or use a different audio amp where the gain is settable to a lower level.

Bob

 

[Ratch]

I had been trying to build a variable wien bridge oscillator . The schematic is shown below - I wanted to change the frequency by using a pot . But it starts to distort after 12 Khz. Also when i am reducing both the capacitors to 1 nF I find the waveform to be triangular more than sinusoidal. Also if I want to drive 0.5 w 8 ohm ospeaker should i use an op amp or an lm386 ? Also how do i change the frequency with one control pin?


View attachment 27711


[mod note: reorientated image]

Look at post #29 of the link below. It shows how to adjust the frequency with only one pot. Also, look at post #11, and follow the advice of Jeri, who doesn't tolerate those folks with lame parts.

https://www.electronicspoint.com/th...a-wien-bridge-oscillator.268455/#post-1607689

Ratch