Sound module issues

Hello,
I recently bought this board, with no specific name:
For Arduino MP3 Voice Playback Module Music Player UART I/O Trigger Amplifier Class D 5W SD/TF Card (some other websites seem to call it "DY-SV5W"
Aliexpress has the most complete documentation I found, but I feel this is a common issue, not related to this specific board, but more related to something I'm missing with wiring... resistors, diodes, etc.
So after I hooked everything up (for "I/O integrated mode 0"), and writing a small program wich is sending commands using binary 8bit signals, there is an odd sound coming out.
here is an example
Note that I have tried powering the module isolated from arduino (from a different source), And with/witout the 5v pin,
No change, same result.

You need to power the module otherwise it will be back powered through the IO pins, which is not ideal.

What is connected to the 3.5mm audio output? Test with a plain set of unpowered headphones.

as I mentioned before, I have tried everything, powering the board, isolating the power supply from arduino, tried headphones on 3.5mm, even tried single speaker on the output pins of the soundboard, the same result in any case.
One idea that I have that it might be from the sound format, maybe something related to the bitrate? I have tried different formats of wav, and seems like it's affecting the noise somehow, but doesn't eliminate it.
I couldn't find any documentation related to the specific format of the audio file.

Try plugging a battery powered USB powerbank into the "download" port of the bare board and compare.
Does the volume of the clicking change when you adjust the volume trimmer?
In the interest of excluding other unlikely possibilities, maybe also try with a different SD card.

You may simply have a defective unit. Ask the vendor if they can supply a known good wav file to test with and if there are any other wiring issues that you should know about. If this were an easy/common problem then they would likely have instructions in the product listings in order to avoid unnecessary product returns.

Not familiar with this board specifically... (kinda reminds me of a bloated/more featured DFPlayer module)..

I got the same 'noise' form my DFPlayer when:

  • not powered correctly
  • not using the correct .wav file formats..etc

What is your Vcc voltage ? (what is the SOURCE voltage connected to the zener diode ?)
Why is there a 5.1V zener diode connected there with NO current limiting resistor ?
Did you MEASURE your Vcc at the CATHODE of the zener ? (the voltage across the zener)

Hi,
That amplifier is "motor boating" by the sounds of it.

What have you plugged into the phono socket?
In the video, what are we listening to, speaker/headphones/beads?

Have you connected a proper speaker to the speaker terminals?

Have you put any bypass caps on the 5V supply to the board?
Try 0.1uF and 100uF cap across the input power terminals.

Tom..... :slight_smile:

raschemmel:
What is your Vcc voltage ? (what is the SOURCE voltage connected to the zener diode ?)
Why is there a 5.1V zener diode connected there with NO current limiting resistor ?
Did you MEASURE your Vcc at the CATHODE of the zener ? (the voltage across the zener)

Sorry for the late reply.
I thought that's just a diode. I was trying to minimize as much as possible any eventual noise from Arduino to the board. That pin is the "Busy" signal from the board to the arduino (high when playing)
I tried with a 1N4001 diode, and without it, doesn't seem to make any difference.

I will try to put a bypass caps on a 5v supply to the bouard as suggested, and let you know about the results.

Another weird thing is that the onboard volume adjustment doesn't seem to have any effect.
In the video it's a regular 110v speaker, but tried without success headphones and even direct input pins speaker.

I have used 2 different MicroSD cards, and even 2 different modules to make sure is not defective. same result

I agree, the sound is definitely “motorboating” which is positive feed back from the amplifier output to input. Add the extra bypass caps to the power. Every time the amplifier tries to produce a loud sound, the supply voltage drops, causing the input to the amplifier to think the signal level has dropped, then the voltage recovers with a “pop” and the whole process starts over.

Speakers are rated with impedance, such as 4 Ohm, 8 Ohm, etc. Never “regular 110v speaker,”. Are you thinking of powered speakers like computer speakers? Are you using a speaker that matches specs of the board?

Paul

Hi,

I had exctaly the same issue controlling SV5W with arduino.
I finally found the solution after hours of test, capcitors, isolating supplies, ...

The problem is the arduino pin not delivering a nice LOW state, just add a transistor as interface for each control line and it will work without any noise.

I used BC547 with 1k resistor between arduino pin and base, collector to SV5W module and emitter to GND.

JP
Belgium

Audio circuits should have a 1uF electrolytic
in SERIES to couple the AC signal and DEcouple
DC.

thanks for the solution. greately appreciated.