Any ideas why my amp buzz's......

Any ideas why my amp buzz's when I hook my tv up to my Integrated amplifier? I use two different pair of speakers: Triangle Zerius and Quad 12L Pro Actives. It only buzzes when the Quads are hooked up not with the Triangles. The Quads have 40/60 watt amplifiers built in and they are hooked via pre out on my integrated using analysis-plus interconnects right into the back of the Quads. Any comments or suggestions would be a big help till I buy a pre amp for the Quads.

Thanks,
Tom