buffer circuit of 5 band audio equalizer

Thread Starter

indusk9912

Joined May 15, 2022
12
I'm making a 5 band equalizer based on a circuit diagram I found on the Internet.
I implemented the entire circuit on a breadboard, but it didn't work.
I'm going to proceed with this circuit while checking if it works properly every time I finish a part, but the buffer part (gain 2, non-inverting amplifier) doesn't seem to be working properly.
I learned that a buffer circuit is used to reduce the noise of an input audio signal, and I know that the shape of the input signal and output signal should be similar.
However, in the circuit implemented on the breadboard, the output signal is not output properly, and in the pspice simulation, 0V or less is cut off and displayed.
Is this circuit diagram wrong? Or am I having this problem because I haven't finished the whole circuit yet?

whole circuit diagram
1669292143754.png

buffer circuit - it's 5band( 60Hz, 250Hz, 1000Hz, 4000Hz, 16000Hz) so i put 60hz Sine wave.
1669293646714.png
pspice simulation
1669293639777.png
 

Thread Starter

indusk9912

Joined May 15, 2022
12
Thank you all for your help.
After modifying the buffer part, I made the whole circuit, but seeing that it doesn't work, there seems to be a problem with other parts.
I'm trying to find another circuit diagram and make it. thanks again!
 

Audioguru again

Joined Oct 21, 2019
5,198
The fixed buffer works fine and the output buffer is also fine.
I simulated the middle filter and it works but its bandwidth is too narrow for an equalizer that has only 5 bands.
I did not simulate the other filters, here is the middle filter:
 

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