mixer hum. shielding problem?

[jokerone]

I just put a new sound card in my computer. before that the USB card carried the audio to the computer. now its patch cables. They are shielded, but none of the instrument patch cables are shielded that I'm aware of.

Is the hum from electronic interferance? how can I tell?

thanks

 

[Seidy]

which card are you talking about?

 

[Bobbsy]

....and what have you got plugged into the sound card? A mixer? Instruments directly? Also, are your patch cables balanced or unbalanced?