I2S Potentiometer and Headphone Issues

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hutch78uk
Posts: 6
Joined: Fri Oct 11, 2019 4:04 pm

I2S Potentiometer and Headphone Issues

Post by hutch78uk » Fri Feb 25, 2022 10:00 am

Hi All

This is my first build and I have been making slow yet steady progress. This was up until I addressed the audio for my Gameboy Zero.

I am using the Adafruit MAX98357A combo DAC/AMP along with an external speaker, headphone jack and a 5 pin potentiometer. By sifting through a few tutorials and the Adafruit website I was able to get sound coming through the speaker without the potentiometer connected, however upon integrating the potentiometer it caused the sound to go very quiet and crackly, even at full volume. I experienced similar issues with the headphone jack. As I said, sound through the speaker was crisp and clear and when I plugged in a set of headphones the speaker stopped and the sound was redirected through the headphones. Unfortunately the sound quality through the headphones was incredibly poor, to the extent that you couldn't tell that it was the Sonic the Hedgehog theme tune. This issue occurs both with and without the potentiometer connected.

My current wiring setup is illustrated below -
gb-zero-audio.jpg
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Have I got this right? Could it be a poor quality potentiometer/headphone jack, or a bad soldering job that is causing the issues?

Many thanks for everyone's help :)

hutch78uk
Posts: 6
Joined: Fri Oct 11, 2019 4:04 pm

Re: I2S Potentiometer and Headphone Issues

Post by hutch78uk » Tue Mar 01, 2022 7:31 am

After a lot of researching and fiddling I decided to go back to breadboard basics.
IMG_4143.JPG
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It seems that the wire configuration does work and the issues were likely caused as a result of dodgey soldering or perhaps thin/dodgey wires. :roll:

I have to say that the circuit is very temperamental with the potentiometer added. Connections to the pot seem unreliable and the it also seems to reduce the volume of the audio by quite a bit. On top of this you only need to reduce the pot dial by about 5 percent for the volume to be reduced to zero.

I'll do some more research as to the reasons for this but it's very likely I may be posting another support question soon :?

Any advice would be most welcome :)

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