I’m using a GPD2846A MP3 Player Audio Decoding with ESP32 and I receiving a loud buzz sound, like a bee when I power the pin.
When I connect directly to the font, it sounds normal.
I also tried with DFPlayer, with the same result.
I’m a total beginner, please be advised.
Welcome to the Blynk forum… we help with Blynk related things, not audio decoding 
Ah ok, I think Blynk could be used to control a simple audio device control. I did not are aware that it couldn’t.
It CAN control stuff and display data from anything that would otherwise connect to a GPIO of an Arduino/ESP/RPi… like a button, potentiometer, display, sensor, etc… If by control we meen the simple or complicated “thing” first has some library and/or code already used to do it’s simple or complicated “thing” and then Blynk becomes the alternate HMI option to the aforementioned buttons, displays, etc.
A good example of this source of confusion was one of the initial Widgets called a Music Player… In reality just a neat looking GUI of “generic music player” type buttons that simply signaled some needed code to respond, but many thought that it was the actual music player In and of itself But when added to an appropriate MP3 add-on board and the associated code… then it really looked and “played” the part.
Ok…
But anyone has successfully used an ESP32 with the famous DFPlayer board? That what I am asking.
It has their own library but I couldn’t make it happen throught Blynk interface.
I don’t know… have you searched this forum for any pertinent keywords… perhaps something like DFPlayer 
Really? I never figure that. Perhaps I can also try to find in some search website. I heard one called “Google”. What do you think?
These smart a… answers make anyone give away of the community.
But it sounds like you haven’t looked. I found one (older) topic in about 5 seconds… and I am not even interested in (nor have) a DFplayer board. And any issues seemed to be related to the player library, or users programming abilities, not Blynk.
However, I HAVE (as have many others) used many other discrete devices and their controlling libraries AND interfaced them with Blynk, so we know it can work.
If someone wishes support… we recommend one put some visible efforts into it, not just demand answers.
I wish I had thought of that one… oh, wait… 
Nah, not worth it… just another person looking to get something for little effort and getting ticked off for having that fact made clear, albeit in my less than cuddly teddy bear 
way that they expect 
I assume that the noise is due to esp32 activity.
Maybe he’s using the same power supply?
Maybe it doesn’t have a filter at the 5V input?
Anyway, it has nothing to do with Blynk 
@bragoose you’ve come here looking for help, so follow the forum rules and keep it friendly please.
You’ll also find that you’ll get more assistance if you start by explaining up-front what it is that you’ve done so far, and which Blynk comm7nity forum topics you’ve already read.
Saying things like:
Doesn’t tell us much about your problem. Which ‘pin’ are you referring to, and what are you powering it with?
The type of MCU used to control the DFPlayer isn’t that critical. Searching this forum (as opposed to searching google) will return a number of topics that explain how to control the board with an MCU running C++ code, and that can easily be adapted to run on your ESP32, with a few changes to the WiFi connection code and physical pins used. The important thing, from your point of view, is to do that research and understand in general terms what is possible. If that suits you’re needs then experiment with the hardware you have, and with Blynk. If you have a problem then share in detail what you’ve done, and what your problem is, and people will try to help (as long as you’re friendly with it).
If Blynk doesn’t do what you are looking for with your hardware then continue your search for a solution that is capable of meeting your requirements.
Pete.
