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Jim
Jim
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Is this a suitable sine wave osc? how would I best control the frequency?

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Jim
Jim
  • 3.4k
  • 2
  • 31
  • 39

Is this a suitable sine wave osc? how would I best control the frequency?

Overview-

I'm making a bank of analog sine wave oscillators and I'm interested in keeping the design compact.

I've started by making a Wien Bridge oscillator. As I'm working from a single power supply and I'm trying to keep the design small, I've been using the LM386n-1 IC.

I'll be using the oscillators to do some additive audio synthesis, maybe some FM and I'll probably need some of the oscillators as LFOs.

My questions are-

Is this a suitable approach for making a compact analog sine wave oscillator?

Also, how would you suggest I control the frequency, which component value should be changed to achieve this? - I've tried messing with all the resistors to change the pitch, but they all seem to be interdependent.

Here is the circuit I've been working from, it's from the National Semiconductor LM386 Low Voltage Audio Power Amplifier datasheet-

wien bridge LM386

And this is what my implementation looks like, I don't have a suitable incandescent bulb so I've just replaced it with a 1KΩ pot. I'm still not sure what I'll use in the final circuit as AGC, suggestions are welcome.

my wien bridge LM386