Thanks Heyraz. Let me provide more info. My main power amp has both AC ground and signal/circuit ground wired to the chassis. One of my sources, SlimDevices Transporter, has both AC ground and signal ground wired to the chassis also. So does my preamp. They don't hum at all.
My secondary power amp had the same setup too but it did hum. The hum stopped after I disconnected the signal ground from the chassis.
My system does not have popping sound nor audible noises from the speakers. I am also an electrical engineer with lots of formal education in EE. But I'd like to learn from others who have practical hands-on experiences with their audio equipment. There are a lot of things in audio gears that school books didn't teach. Or I have forgotten most of them.....
My secondary power amp had the same setup too but it did hum. The hum stopped after I disconnected the signal ground from the chassis.
My system does not have popping sound nor audible noises from the speakers. I am also an electrical engineer with lots of formal education in EE. But I'd like to learn from others who have practical hands-on experiences with their audio equipment. There are a lot of things in audio gears that school books didn't teach. Or I have forgotten most of them.....