# MP3 Trigger background noise **URL:** \ **Category:** Sound & Audio\ **Created:** [November 20, 2020, 9:25am UTC](https://community.sparkfun.com/t/mp3-trigger-background-noise/40949 "2020-11-20T09:25:18Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![oltop](https://avatars.discourse-cdn.com/v4/letter/o/b77776/32.png) [@oltop](https://community.sparkfun.com/u/oltop)\ **Post date:** [November 20, 2020, 9:25am UTC](https://community.sparkfun.com/t/mp3-trigger-background-noise/40949/1 "2020-11-20T09:25:18Z")
Hi, i have a Qwiic MP3 Trigger and it has some backround noise wehen it is not playing a sound file. The electrecity source is a bench top powersupply with 12V and a adjustable stepdown power regulator to 3.3V. At the other side is a 20W class D amplifier connected vie 3,5mm audio jack. I tried the following things: - played musik from a nother source to the amplifier / no noise - taped off the earth connection on the power supply / no result - changed from the amplifier board to a battery powerd bluethoothspeaker via 3,5mm audio jack / no result - changed the 3,5mm audio jack to a soldert connection between the boards / no result - changed the power source to a 12V Battery / no result - powerd the MP3 trigger direcly with 3,3V from the benchtop powersupply and the amplifier with a 12V Battery / no result Can somebody help me with my Problem? ---
**Author:** ![TS-Brandon](https://avatars.discourse-cdn.com/v4/letter/t/cc9497/32.png) [@TS-Brandon](https://community.sparkfun.com/u/TS-Brandon)\ **Post date:** [November 25, 2020, 6:06pm UTC](https://community.sparkfun.com/t/mp3-trigger-background-noise/40949/2 "2020-11-25T18:06:55Z")
Can you provide a picture of your setup? Are you able to add a decoupling capacitor on the power lines going to the MP3 trigger? [https://learn.sparkfun.com/tutorials/ca … n-examples](https://learn.sparkfun.com/tutorials/capacitors/application-examples)