Thread: Hauppage USB TV/FM line-in noise/whine- Grounding

Hi there,

ive got my PC setup in the boot. Nicely grounded etc etc no problems on that front with noise. I have 2 4 port USB2 hubs which are under my dash which are joined by 2x 5m extension leads to the PC in the boot. Under the dash i have my Hauppage USB TV/FM tuner. The line out from it then runs down the car via RCAs to the linein of the sound card. Now the problem i have is when the linout volume it about 50% i get whine when the cars running. I know this is a grounding issue, as when i rest just the outside of the USB plug on the metal on the usb hub ports i get he noise.

Its because the hauppage is tryign to ground itself down the RCAs as there is a difference in resistance of the USB ground to the PC and down the phonos. With car audio kits its aways best to keep the grounds short.

Would it be OK to somehow on the hauppage disconnect the USB grounds from the ciruit board so it didnt use the usb cables ground and instead have a tag that comes out of the hauppage that i connect via a short lead to a decent ground on the chassis on the CAR body, EG like a head unit would be connected?

Anyone else have this problem with USB audio devices and noise

cheers

Jamie