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newb question
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newb question

by foti on Sat Feb 27, 2021 10:43 am

I have a PAM8302a and a MAX4466 that I'm trying to get going here. I'm a software person so please bear with me. After getting the boards I wired them to a USB charger but all I got was popping and distortion from the speaker - nothing that sounded like what was being spoken. Adjusting gain and volume did nothing.

So I thought maybe it was the power supply and wired each board to its own battery but now I get nothing at all. See attached, please explain what I'm doing wrong or if I need new parts.
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foti
 
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Re: newb question

by adafruit_support_bill on Sat Feb 27, 2021 2:01 pm

I don't see any ground connection between your mic and your amp. You need a common ground for a signal reference.

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Re: newb question

by foti on Mon Mar 08, 2021 9:12 am

I connected a common ground with battery, which didn't work. I also tried using one of your Mini Lipo chargers which also didn't work. Tried turning potentiometers in all directions, still nothing. At least before when I tried the Lipo charger I got some poppoing noises, which I'm not getting now. Are these part defective or am I still doing something wrong?

IMG_0216.JPEG
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Attachments
IMG_0218.JPEG
IMG_0218.JPEG (801.56 KiB) Viewed 69 times
IMG_0213.JPEG
IMG_0213.JPEG (758.14 KiB) Viewed 69 times

foti
 
Posts: 5
Joined: Fri Jan 22, 2021 12:44 pm

Re: newb question

by adafruit_support_bill on Mon Mar 08, 2021 9:52 am

Since you have a single-ended input, you should connect the Audio In - pin to GND.

If there is still no sound, disconnect the signal wire from the output of the mic and briefly touch it to the VIN pin. You should hear a popping noise. That will verify that the amp is functioning.

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Re: newb question

by foti on Thu Mar 11, 2021 2:15 pm

I'm not sure I understand and don't want to randomly connect stuff up. Could you please highlight the attached diagram with Windows Paint or other editing app to draw the connections I need to make?

diagram.jpg
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foti
 
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Re: newb question

by adafruit_support_bill on Thu Mar 11, 2021 2:38 pm

To test that the amplifier is working, connect as in the first diagram. Briefly touch the end the the 'Audio In +' wire (yellow) to the 5v pin on your charger board. You should hear a popping noise from the speaker. That will verify that the amplifier is working.
diagram2.jpg
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The second diagram is how everything should be connected for use with the microphone. Note that 'Audio In -' should be connected to GND.
diagram.jpg
diagram.jpg (69.59 KiB) Viewed 50 times

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Please be positive and constructive with your questions and comments.