I recently upgrated my system with a Gygabyte GA-Z68X-UD3H-B3 motherboard and Corsair 500R case, but now when I plug my amplified into the line out jack on the board (green jack), there is a mild hum sound. This didn't exist with the old system, so it's definitely a result of going to this new motherboard and case. Could it be that the MB isn't properly grounded to the power supply ground?
More aboutissue line gygabyte z68x ud3h
Onboard sound is not shielded go with a sound card solution