I am currently using a PVR-150 capture card and a STB for Live and Recorded TV. I admit that I don't use this function very often as the picture isn't(never has been) as sharp as just viewing through the STB, but now I have noticed a audio hiss on both live/recorded TV.

Have I set up the pvr 150 card incorrectly or am I simply under spec'd?

What capture card should I upgrade to bearing in mind I have to also use a STB.