Uno to DFplayer to PAM8403

Other Hardware Audio
1

Hi, I am trying to set up a halloween project 'monster in a box'
I am using an UNO which when a button is pressed it activates lights, sounds, smoke machine (all the spooky things!)

However I am having issues with the sound, I am trying to play the audio through a guitar amp via a AUX lead, so my setup so far is UNO > DFplayer > PAM8403 > Aux Lead > Speaker/amp

I tried originally with just the DFplayer but the sound was just too quiet so I introduced the PAM8403 which has helped with the volume but the sound quality is not great. Lots of static etc, the sound track has a bass-y heartbeat but it just comes out as two static sounds rather than the "dum dum" you would expect.

Would anyone be able to advise me on the wiring setup for this, I have checked all the soldering and it all seems ok to me, but I am guessing I have the outputs going to wrong way or something like that but I have tried various setups and they either sound awful or you can't hear the full sound, can you actually connect a PAM8403 to a single aux lead?

My wiring as it stands:
I have the df player on a PCB board and the 5v and gnd coming via the Arduino
so Arduino 5v to pcb + channel
Arduino gnd to pcb - channel
pcb + to dfplayer VCC
pcb - to dfplayer GND
pcb + channel to PAM8403 power +
pcb - channel to PAM8403 power -
pcb - channel to PAM8403 G input
dfplayer spk_2 to PAM8403 L input
dfplayer spk_1 to PAM8403 R input
PAM8403 Right out + to right channel on aux lead
PAM8403 Right out - to left channel on aux lead
Aux lead GND to - channel on PCB board

2

Those two pins are for a speaker. Use the two DACR pins to your amp.

3

You are sending digital sound to a digital amplifier and you have discovered the results. Use a linear amplifier or preamplifier instead of the digital PAM8403. That device will work fine on real analog audio.

4

Ok I have removed the DFplayer altogether and connected the DACR pins as you suggested, there is a lot less static and the heartbeat is actually noticeable now, there is still some static though, especially on the heartbeat, the other sounds are all fine, could this be caused by bad grounding. I'm just grounding the aux cable to the PCB.

5

Haven’t had my first coffee yet, but that sounds a contradiction! If there’s no DFplayer, how can you connect its pins?

Time for a schematic and photo?

6

Ah! sorry I meant the PAM8403 , I have removed that altogether.
So now:

DFplayer DAC_R to Right audio channel on aux cable
DFplayer DAC_L to Left audio channel on aux cable
Gnd audio channel on aux to Gnd channel on PCB

7

Is the player now working satisfactorily?

8

Its better than it was but I still have a lot of static noise on the heartbeat.

9

Maybe you're hearing the aliasing that you missed at lower volumes.
Maybe it's overdrive, clipping.
How's the quality from the headphones?

10

Through headphones the audio sounds ok to me - https://drive.google.com/file/d/1Ms30R95-pdxBDowY8dngp2AuxeAmZ05u/view?usp=sharing

I can't upload the file as I'm a new member to the forums but hopefully that link works.

11

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