Hi, I have Panasonic SC-HT700. Here is a link to it's manual, if it can help <http://service.us.panasonic.com/OPERMANPDF/SCHT900.PDF> So, my problem is that if I connect my sound card to Panasonic AUX or line-in input, there is very annoying noise. I tried both with line-out and phone outputs of the card. The aux and line-in inputs seems to be ok, as I use line-in with my cable box, and also I have tried the aux input with my other DVD player. And there is no noise. When I connect speakers to my sound card, there is no noise as well. So, I thought that maybe the case or the card (it is onboard) are not well screened and this can cause the noise. But I tried with some other cards, on different computers, both with onboard and PCI cards, and always there is a noise. After all I gave up, and bought USB Soundblaster MP3+. Ans still, there is a noise. The strange thing what I noticed is, that when I unplug my laptop from the power supply, the noise is dramatically lowered (still does not disappear completely). So I guess there is something with the electricity, but I don't know what. Does someone has any clue what to try next? The bad part is that this Panasonic unit does not has digital input, so I can not use the digital output of the sound card (I guess this should solve the problem). So, please, any advises. Will surge protector or UPS help? Thanks Sunny P.S. This noise exists even if I connect the soundcard to the TV (also Panasonic, if this matters).