I have a small voice recorder module based on the ISD1820 chip. It's supposed to drive an 8Ω, 0.5W speaker. It works but the speaker volume is not very high. I thought I could possibly use an LM386 audio amp to increase the volume. I tried the headphone amp circuit by Tracecom shown in this thread:
http://forum.allaboutcircuits.com/showthread.php?t=73725
I connected the speaker + output from the recorder as the + input to the 386 through the resistor and capacitor and the - speaker output to ground. The recorder and 386 are fed by the same 5V power supply. The circuit is on a breadboard.
The circuit does amplify the voice but there is also a very loud buzzing noise.
Is there a way to clean up the background noise?
http://forum.allaboutcircuits.com/showthread.php?t=73725
I connected the speaker + output from the recorder as the + input to the 386 through the resistor and capacitor and the - speaker output to ground. The recorder and 386 are fed by the same 5V power supply. The circuit is on a breadboard.
The circuit does amplify the voice but there is also a very loud buzzing noise.
Is there a way to clean up the background noise?