I am working on a DIY Bluetooth stereo system, the Bluetooth board which I use produces too much noise.
I am using a 24v 4A SMPS power supply for amplifier board and LM7805 voltage regulator ic for 5v Bluetooth decoder board.
I observed that the noise reduces when I touch the metallic parts in the board.
I am also using the same power supply for the speaker protection board and gain board (regulated 12v).
If I use a separate power supply using 12-0-12v transformer for the speaker protection board, gain board and Bluetooth board, the noise issue will get solved? Also I can use the transformer center tap to ground the body parts!!
Is there any other methods to solve this issue?
I am using a 24v 4A SMPS power supply for amplifier board and LM7805 voltage regulator ic for 5v Bluetooth decoder board.
I observed that the noise reduces when I touch the metallic parts in the board.
I am also using the same power supply for the speaker protection board and gain board (regulated 12v).
If I use a separate power supply using 12-0-12v transformer for the speaker protection board, gain board and Bluetooth board, the noise issue will get solved? Also I can use the transformer center tap to ground the body parts!!
Is there any other methods to solve this issue?
You might try powering the bluetooth board from a clean linear power supply and see if that helps. SMPS most commonly produce some or a lot of electrical noise that can get into sensitive electronics. Also, the fact that touching something changes the sound suggests that the board is acting as an antenna somewhere and your body is acting like a shield, or something more or less along those lines.