neekoo
Newbie level 4
Hi there
I have a situation here regard to the audio amplifier noise.
This is the audio source circuit (CODEC) :
This is the audio amplifier circuit :
And here it is the audio amplifier PCB layout :
There are some facts :
1 - With no input to the amp there is no noise at speakers output at all.
1 - When I Connect my audio source to my amp there is a lot of noise which change with cable movement or touching components in the circuit.
2 - When I connect a different audio source (rather than my source from picture 1) for example from computer output to the amplifier there is no noise (very low noise).
3 - When I connect my audio source to a different amplifier (for example my computer speaker) there is no noise at all.
4 - When my audio source (CODEC) is off there is noise but when I put a 1K resistor at the amp's inputs , noise will be disappeared. But when CODEC is on the resistor has no effect on the noise.
I have a situation here regard to the audio amplifier noise.
This is the audio source circuit (CODEC) :
This is the audio amplifier circuit :
And here it is the audio amplifier PCB layout :
There are some facts :
1 - With no input to the amp there is no noise at speakers output at all.
1 - When I Connect my audio source to my amp there is a lot of noise which change with cable movement or touching components in the circuit.
2 - When I connect a different audio source (rather than my source from picture 1) for example from computer output to the amplifier there is no noise (very low noise).
3 - When I connect my audio source to a different amplifier (for example my computer speaker) there is no noise at all.
4 - When my audio source (CODEC) is off there is noise but when I put a 1K resistor at the amp's inputs , noise will be disappeared. But when CODEC is on the resistor has no effect on the noise.