Hello everyone,
I'm posting here after long time and again this time I have a query about music and amplifiers. I recently built a music system with a usb-mp3 module with Bluetooth function and a audio amplifier board based on LA4440 chip. I used a common 12 Volts 3 Ampere transformer for powering both the module and amplifier after adding a 5 Volts regulator for powering the module. I assembled the whole system in a metal cabinet. But on powering up the whole system I found a high frequency buzzing noise (same as sound of continuity buzzer sound of digital multimeter) from speakers which I suspect is coming from the Bluetooth module and being amplified by the amplifier. When I play music from the module using flash drive the noise appears to be suppressed by the music/song but when I pause the music, the noise can be heard again. I think the noise is actually continuously coming from the module but gets hidden when something is played. I want to know why this module is making this type of weird noise ?
I also have a usb-mp3 module without Bluetooth function but that doesn't make any noise like this when connected to the same system which I built.
I'm posting here after long time and again this time I have a query about music and amplifiers. I recently built a music system with a usb-mp3 module with Bluetooth function and a audio amplifier board based on LA4440 chip. I used a common 12 Volts 3 Ampere transformer for powering both the module and amplifier after adding a 5 Volts regulator for powering the module. I assembled the whole system in a metal cabinet. But on powering up the whole system I found a high frequency buzzing noise (same as sound of continuity buzzer sound of digital multimeter) from speakers which I suspect is coming from the Bluetooth module and being amplified by the amplifier. When I play music from the module using flash drive the noise appears to be suppressed by the music/song but when I pause the music, the noise can be heard again. I think the noise is actually continuously coming from the module but gets hidden when something is played. I want to know why this module is making this type of weird noise ?
I also have a usb-mp3 module without Bluetooth function but that doesn't make any noise like this when connected to the same system which I built.
