Class-D Amp : Battery Powered : Head-Breaking Ground Loop

[Xarlitos]

hello can u plz take photo of the mp3 module and show where to desolder?
i have the same problem and it will help me alot !
thanks

Hi idanha,

All my stuff is at the Garage/Workshop and only on Sunday I'll have a chance to take pictures, but, if you look at the one I'm attaching you might have a good idea of what you need to desolder.

If you have this same module, you'll have a hard time doing this since the solder is crappy and the board starts melting pretty fast, I would advise to be very patient, use a low temperature, use Rosin Flux and a Desoldering Pump (I think that's how it's called), it was the safest way I found without blowing my patience.

After further testing that I've done and since this seems to be of interest for some people, I think I understood why some sellers soldered the connection.

IF you don't connect the module to an amplifier and GND and AGND are not soldered, the module will turn on but will stay in a "hibernated" state, you won't be able to do anything, it will just show "Hi" on the screen.

IF you leave GND and AGND soldered together, you can use the module alone, without any noise, to power headphones or small speakers (I think it puts out roughly 2W).

So, basically, if you want to connect this type of module to an Amp, desolder.
If you want to use it to power speakers directly, leave it be.

I don't understand why no-one around the Web took the time to explain this, I'm sure someone figured it out...Selfish people 😛

Let me know any developments, now I'm curious to see if I did manage to help others with this quest that took me forever to finish (yes, I'm a noob...).

 

[Xarlitos]

Hi
Xarlitos good to hear from you again
nice to know you didn't give up after all those trials and setbacks!
very big I think
to your success

Thanks for all the help infinia,

I consider this the first step to achieve some greater Audio skills, meanwhile I had time to make the design a little better and with greater functionality, will post some pics of the final product once it's done (another week, give or take).

I will engage in a smaller project that I have in mind that will help me develop better soldering skills and understanding of the overall "Audiophile" subject, once that's done I was thinking of following that famous TPA3116 thread here at DIYAudio and engage myself in what I consider a HUGE project for myself (assembling the Amplifier from scratch), what do you think about that?

Thanks for the "beer", if you ever come to Portugal I'll pay it back 😀