I would check the soldered connections on your rca plugs to make sure they are tight. The rca "barrel" usually can easily be unscrewed to expose the connections.
Hum In Theta Pro Basic IIIa
I'm keep getting humming sound from my Theta DAC. It is connect to Meridian 518 DSP and Meridian is connected to my old CD-Player. Strange thing is, if I'm twisted the cable connected to RCA out from theta a bit the hum is gone. I got rid of the Meridian once, but still getting Hum sound. I will really appreciate if you guy help me out? Thanks.