Amplifier Humm/Buzz

[Damith Neelawala]

I have build a amplifier that based on a TDA2040 + TDA2030 chip based pre installed board ( Probably a Chinese One).the problem is that the amplifier produce lot of humm/Buzz or whatever it says( i exactly didn't know The Word..Sorry).when i close my hand to the amplifier or while turn up the control knobs the noise is getting higher.please can enyone give a solution for me guys..thanks...

 

[slipperybidness]

I have build a amplifier that based on a TDA2040 + TDA2030 chip based pre installed board ( Probably a Chinese One).the problem is that the amplifier produce lot of humm/Buzz or whatever it says( i exactly didn't know The Word..Sorry).when i close my hand to the amplifier or while turn up the control knobs the noise is getting higher.please can enyone give a solution for me guys..thanks...

Mechanical hum at the amp?
Or electronic hum through the speakers?

If mechanical hum, then you need a better transformer, better/stronger chassis, or you need some way to stop the mechanical hum.

If through the speakers, then likely you have a ground loop, or you need better grounding on the PCB.

 

[Speedskater]

when i close my hand to the amplifier or while turn up the control knobs the noise is getting higher.please can anyone give a solution for me guys..thanks...

That's a clue to look for a broken or missing shield or ground connection.

 

[TLS Guy]

Does the amp hum when only connected to the speakers? If yes, you have an internal ground loop or induced hum from the transformer.

You can remove the transformer and connect it at a distance, and see f that solves it. If it does then the power supply needs to be external, and connected to the amp with a cable.

If that does not solve it, then you need to look at your ground plane in the amp.

Without knowing what you have done, I can't give specific advice. However careful thought and execution of the ground plane is always an important and difficult part of any construction project. It is an area were lots of mistakes are made. The same goes for large and often not so large installations.

 

[Damith Neelawala]

Thanks guys for your Attention & the replies.i check the situation as you guys advised ,and realize that the hum came Through the speakers after connecting. . Then that may be about the Ground Loops as you guys said. without even connecting speakers the transformer generate very little hum but that may be a size can ignoble ...guys ,could you please tell me the better ground looping methods if you can...Thanks for your attentions....