I just had my cable upgraded and the tuner box has multiple audio outputs. I purchased a rather cheap digital audio output cable (startech). My problem is connecting the cable to the box and my AV receiver. The cable barely plugs in and I'm concerned that I may break something if I push it any harder. I do get regular sound using the RCA outputs but was hoping to get 5.1 digital sound from the HD movie channels. Should I be buying a more expensive cable or a specific brand? Is there something that I am missing? I have set my A/V receiver to the correct digital input assign in the menu, just no sound what so ever coming out.