hum in long cable

[TLS Guy]

If he doesn't have ANYTHING grounded in the audio setup, yeah. I know you asked that earlier, but I don't see a response answering you from him about that. If his TV or subwoofer or something is grounded, the loop will persist because it will still be connected to the computer. Or if he adds something that is in the future.

I agree with you that if nothing else is grounded over there, then the cable isolator should be enough, but...I just can't imagine nothing being grounded over there. Just about all my gear has a ground.

I still believe in the direct boxes for doing computer to receiver connections though, for impedance matching alone.

The key to this is that when the TV is disconnected from the cable system there is no hum. Logically then, if he puts the isolator either between the cable outlet and the splitter, or between the splitter and the TV his hum will stop.

 

[stanlee]

try disconnecting the cable from the cablebox.
If this works then just add aground breaker for the coax.
or try to disconnect the ground from the units.
good luck.

 

[mathyou9]

Before I get a ground isolator, a bit about my soundcard:

Its 5.1 (and 7.1) outputs are entirely analog (no digital outputs.) OTOH, my receiver does not have analog inputs for 5.1/7.1. But it does, of course, have S/PDIF coax and optical inputs to handle such sound.

Anyway, I've been leaning towards getting a new sound card that has an optical output. My question is: Am I correct in thinking that an optical cable (rather than RCA, or even digital coax) would solve the ground loop problem as well?

 

[TLS Guy]

Before I get a ground isolator, a bit about my soundcard:

Its 5.1 (and 7.1) outputs are entirely analog (no digital outputs.) OTOH, my receiver does not have analog inputs for 5.1/7.1. But it does, of course, have S/PDIF coax and optical inputs to handle such sound.

Anyway, I've been leaning towards getting a new sound card that has an optical output. My question is: Am I correct in thinking that an optical cable (rather than RCA, or even digital coax) would solve the ground loop problem as well?

Only if your TV is not connected to your receiver by anything.

 

[mathyou9]

Only if your TV is not connected to your receiver by anything.

Right now the TV is not connected to the receiver, but it has an optical [fixed audio] output that I've considered using to connect to my receiver. If both my computer and TV are connected to my receiver via optical cable, a ground loop would still be avoided, right?

 

[TLS Guy]

Right now the TV is not connected to the receiver, but it has an optical [fixed audio] output that I've considered using to connect to my receiver. If both my computer and TV are connected to my receiver via optical cable, a ground loop would still be avoided, right?

Correct! Good luck and enjoy. You are now a ground loop expert!