hiss

[carlosfm]

I intend to low the gain by 50%, in your opinion is that enough?

Yes.
Do that.
That's the first thing I would do right now.

 

[jaudio]

I lower the gain by 50%. The hiss went down some but it was still audible at 7ft.
I rechecked the connection from drv134 to the lm3886 modules.
I found loose connections,I reconnection them. The hiss is gone.
I also added a resistor and cap in parallel bewteen chassis and power supply ground


Thanks for the help!