hello everyone, i have a problem, i am using a Bluetooth module in amplifier. when i power it with linear regulator it gives a continuous white hum and when it is powered with 5v adapter it works accurately but i don't want to use an adapter. can any one suggest me a proper sollution???????????? 😕
You will have to apply another wiring amplifier. Can you show me the amplifier schematic used ?
Show us a diagram of your setup - I assume the linear regulator contains filtering?
Sounds like a ground loop issue - does the 5V adapter have an earth pin on the plug?
this is the schematic of supply to power up a pre amplifier the section above relay is latching circuit when preamp is switched on an led indicates the power but preamp stays at standby until a push button is pressed. the problem is that if i use a 5v adapter, mp3 module will not be controlled by this circuit. 5v regulator don't work so well.
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I have drawn the correct wiring method of the amplifier in the picture below. In your case, if you implement SM Connector, do not use a jumper
or don't use resistor of 10 Ohm.
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i have used the same wiring but the problem is with mp3 module when it is driven with 5v regulator it gives noise even with filter. i tried to use 5v bulk converter but still the same issue. i have atteched the image of mp3 module and bulk converter i used.
https://ae01.alicdn.com/kf/HTB1nxbU...-Decoder-Board-Panel-Audio-Module-Support.jpg
https://www.elprocus.com/wp-content/uploads/Buck-Converter.jpg
When I use same supply with7805 Bluetooth give noise. After I use seperate mobile adaptor .then dead silent
no this only drives the mp3 module in preamplifier. i have attached the supply schematic in my previous post.
yes, the issue is that when mp3 module is driven through any king of regulator it gives noise whether there is any input signal or not, in line in mode or bluetooth mode. the only solution is to use a seperate 5v adapter( any mobile phone charger). in this case i will have to design an extra circuit with an extra transformer to switch on the whole thing
Pls check u amplifier is ok . connect with pc or mobile.then volume low to High. Use 2core sheild wire for input.use seperate supply for Bluetooth..this is 3 step.