Cheers, mates! This is my first post, as well as electronics project. I read the forum rules and will get straight to the point.
I'm attempting to use two 5W speakers with a DFPlayer mini mp3 player and a stereo amplifier (wcmcu-8406). I'm using a 10k oHm stereo potentiometer represented as two individual pots in the schematic.
I was able to get one speaker working on a breadboard after following a YouTube tutorial, but now I'm trying to add a speaker and an external power source for the amplifier. The breadboard has such weak connections that I need to solder the circuit, and before I do that, I'd really appreciate if someone with more experience could take a look at my schematic. My main concern is that my secondary power source, a 5V 3A battery pack, may provide too much current to the components due to misuse of resistors and capacitors.
The two sets of adjacent 20uf polarized caps in the circuit are used to replace 10uf non-polarized caps, since I don't have non-polarized caps.
I'm not sure if I'm grounding the secondary power source properly, or if I should use common ground for everything.
And once these issues are resolved, I would like to know which wires will need shielding to prevent distortion or noise. This isn't an audiophile project, but sound quality is always somewhat important with music
Thanks and please let me know if I left anything out or if you have any suggestions. I've never worked with electronics until a few months ago and I appreciate your patience.
Check the data sheet, I did not find one but if my memory is working that is a bridge output and the speaker is not refereed to ground. That being said you need to use both the + and - outputs. On the volume controls I would place the SPK on one end ground on the other and the wiper to the cap for the amp input. That should give you better sound quality and control. Also used an audio taper pot if you can get one.
Thanks, gilshultz! The reason I used common ground for the speakers, rather than the amplifier's L- and R-, was the diagram from Step 8 of this "instructables" tutorial. In Step 6 of that tutorial, the author declaires: " NOTE : DON'T SHORT THE GROUNDS OF THE SPEAKERS, THIS WILL DAMAGE THE IC. FOLLOW THE CIRCUIT BELOW TO ATTAIN COMMON GROUND I could not find the data sheet for that amplifier module, either (WCMCU-8406), but the component in that instructables tutorial seems to be pretty close. Then again, the tutorial is unclear at times and I had to make some assumptions. Do you think I should wire the negative speaker terminals directly to the L- and R- of the amp?
Thanks for noticing the issue with the wipers/pots, I'll correct that by wiring the middle terminal to the cap to the amp. The DFPlayer Outputs should be on the pot's VCC's, if I'm understanding you correctly. I am using audio taper pots
Thanks again, I think I'll be ready to solder if you could provide just one more response as helpful as your first.
Yes! When using it as a bridge both speaker outputs can swing from + to -. Connecting the speaker to ground reduces the power dramatically and per the data sheet destroy the part. Let us know how it goes.
