Portable Speaker Project: Understanding Noise Issues with 3W Amplifier & Bluetooth Module

Hi.
I'm building a portable speaker.
I test electronics - a 3W amplifier and a BT module.
I used it once under an ampli and in a car, everything was fine.
I want to use it for a portable speaker, but plugged in is terrible.
They only occur when I play music - only when there is a signal.
I changed the signal cables 3 times, I gave a 2.2k uF capacitor, with 1k uF it does not help either.
Directly on the cable, this effect does not occur to the phone, so it is definitely the fault of the module.
What can be done in this case? Maybe some shielding?
@
or maybe the amplifier collects interference during bluetooth transmission?
can enclose it in a piece of plaque and connect it to the minus of the system?

mati_323 wrote:

I'm building a portable speaker.
I test electronics - a 3W amplifier and a BT module

Well cool and so what ?!

You haven't provided any data at all, not even the module model!
I reported the post, maybe next time people will start thinking ...

Such an amplifier on the PAM8403
http://diolut.pl/pobarcie/00039147.pdf - documentation
Bluetooth receiver, unfortunately I have not found the documentation.
It's like here http://tiny.pl/g5nhp
2.4 GHz, range up to 10 m, power supply from a 3.1 - 4.2V battery

How long is your cable connecting the amplifier to the receiver?
What is the length between the speakers and the amplifier?

mati_323 wrote:

I changed the signal cables 3 times, I gave a 2.2k uF capacitor, with 1k uF it does not help either.

What capacitors?

What do you feed it with?

The power supply comes from the package - these are rechargeable batteries from an old laptop battery.
There is 3 to 4.1V at the output.
The amplifier works at 5V, it is connected via STEP UP converters.
The cables are short - max 15 cm. The BT adapter is a little longer.
Speakers with an amplifier - also not long, but not thick.
The capacitors are simply desoldered from the old amplifier - they have +/- so electrolytic, if I'm not mistaken.
What have I done so far and it has not worked? :
- Bluetooth module power supply from the original battery - cable length 3 cm
- kicking out the converter - I powered the amplifier from the computer's USB
- as I mentioned earlier, I gave a capacitor before powering the adapter (I did not give a cramp by a boost)
- I connected the BT adapter to the receiver on my package - noise almost inaudible, negligibly small - volume to max
What else will I check:
- I will give kondy before feeding the booster
- will cover the amp with a piece of sheet metal - I will connect it to the ground of the power supply or signal, I don't know xd
I would like to add that when I connect the phone directly to the jack - I omit the BT receiver, there are no noise.
My signal cables are 100% good because I have a cable for applications and power amplifiers made with it

It is possible that the signal from the BT module is too big for this amplifier. Try to reduce the signal by adding a resistor, e.g. 100? (you have to choose it experimentally) on each of the outputs of the BT module parallel to the ground. If the sound level is too low, increase the resistor values.

niebieski55 wrote:

Try to reduce the signal by adding a resistor, e.g. 100? (you have to choose it experimentally)

A better experiment will be to give a potentiometer, sound input to one extreme pin, ground to the other extreme and the output to the amplifier under the middle one.

Szymon but then I have to give a double potentiometer if I'm not mistaken

Oki. Neither the resistor nor the potentiometer unfortunately: /
I tried on 220R, 470R and 10k R, a 10k logarithmic resistor - there is no noise as it is in the extreme left point - i.e. volume 0 xd

Keep the cables to a minimum. What do you feed it with? Maybe the power source is disturbing. Show a picture of the assembled chip.

Tomorrow I will shorten the cables as soon as I can and take pictures.
Regards and I wish you a Merry Christmas