Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Its a low pass filter so I can only think its there to reduce any residual RF or HF signals above audio range which may damage the speaker or cause unwanted modulation effects.
The data sheet indicates it is for bass boost. Note also that the inputs are reversed from the typical amplifier circuits also shown on the data sheet.
Look at the datasheet for the LM386. At the frequencies of the AM broadcast band and the 455kHz IF frequency of an AM radio the LM386 has lots of gain. The speaker and its wires will spray the amplified signal all over the radio causing it to oscillate if the lowpass filter isn't there.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.