Microphone Help: Constant Amplitude w/ No Input

  • Thread starter Thread starter rama1001
  • Start date Start date
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 2K views
rama1001
Messages
130
Reaction score
1
Hello,
I have a circuit that can take the input from microphone and amplify it with OPamp. I have connected everything correct and when i check the output whit no input at microphone still i get output with constant amplitude. I think that was due to gain of OPamp but not sure. The opamp gain is 500 and when if there is any input(song or sound) at microphone it just following the song. Please clear me why i am getting these constant amplutude when there is no input. Is this really due to gain. Please see the image when there is no input.
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    23 KB · Views: 413
Engineering news on Phys.org
rama1001 said:
Hello,
I have a circuit that can take the input from microphone and amplify it with OPamp. I have connected everything correct and when i check the output whit no input at microphone still i get output with constant amplitude. I think that was due to gain of OPamp but not sure. The opamp gain is 500 and when if there is any input(song or sound) at microphone it just following the song. Please clear me why i am getting these constant amplutude when there is no input. Is this really due to gain. Please see the image when there is no input.

Looks like 100Hz (or 120Hz) noise from rectified AC Mains noise. Are there flourescent lights nearby?