We need a mono audio circuit. We checked the PAM8303 first but their website said it's not recommended for new design. That's why we switched to PAM8304, which is stereo. We don't have many needed equipment yet. So we only checked the voltage at each pin. But not sound was produced at all. We will try to test the voltage changes at each pin along the way while supply an audio input.hi Ntp,
Welcome to AAC.
Using a scope did you verify exactly where on the circuit the test signal was interrupted.?
Try injecting a low level test signal into the C12/13 and or C14/16. [ you may have to lift off one end of C12/16]
That will check the amp stage, lets know your results.
I have used the PAM8303 Audio amp without any problem
E
On the other website forum it was asked if the mono PAM8304 has one of its bridged outputs connected to the speaker and wrongly had the other speaker wire connected to ground (thinking wrongly it is a stereo amplifier).
Thank you so much for your advice again. Diodes website does not say PAM8304 is discontinued. That's why we use it. If its product life is ending, can you please recommend another mono alternative? Thank you,A PAM8403 was an old mono amplifier. It is obsolete and not available.
A PAM8304 is a stereo amplifier that is also obsolete but is still available.
Your circuit has many parts that are not needed:
Will modify and try. Thank you for your advice.Your schematic of using the microphone in a single ended configuration is not correct. Also the output from the TS472 should be single ended to the PAM8304. I believe the modified schematic below is correct.
View attachment 233159
I also got my numbers mixed up.
The PAM8304A is a mono amplifier. Digikey has 1530 of them in an 8msop package.
The PAM8403 is a stereo amplifier. Digikey has 25,000 of them in a 16msop package. 3 other packages are obsolete.
Do you understand that the PAM8304A mono output is bridged with the speaker directly connected to its two bridged output pins?
Not really. What we have is PAM8304. Does PAM8304A mean different packaging like ASR? Can you please advise if the attached PAM8304 circuit might work? Thank you!I also got my numbers mixed up.
The PAM8304A is a mono amplifier. Digikey has 1530 of them in an 8msop package.
The PAM8403 is a stereo amplifier. Digikey has 25,000 of them in a 16msop package. 3 other packages are obsolete.
Do you understand that the PAM8304A mono output is bridged with the speaker directly connected to its two bridged output pins?
I thought the circuit in the attached screenshot included PAM8304 connection to speaker? Can you please double check?Your PAM8304 has no speaker connected so it will not work.
We want to see if you wrongly connected one speaker wire to ground like you would with a normal stereo amplifier.
I'm not sure what you mean? How do you prevent acoustical feedback howling with any mic and speaker.How will you prevent acoustical feedback howling?
Where did I post any preamp connection instructions? The mic is connected to In+ and In-.The preamp connection instructions are a nightmare. Poorly translated?
I don't know, but I do see that you can change component values to provide roll off of the high and low end.Why is the preamp connected with differential inputs and outputs when an ordinary electret mic is unbalanced.
I see extra parts.
When you buy Cheap then you get cheap, defective of fake stuff from "over there".the Aliexpress PCBs come without any information
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