Help connecting my Dual CS 505-3 to JBL Creature speakers?

I have a pre-amp (a href="http://www.maplin.co.uk/Module.aspx?ModuleNo=28732&C=Froogle&U=28732&T=Module)" rel="nofollow"http://www.maplin.co.uk/Module.aspx?Modu…/a and a 3.5mm Stereo Socket to 2 x RCA/Phono Plugs 0.2M Cable (a href="http://www.amazon.co.uk/3-5mm-Stereo-Socket-Phono-Plugs/dp/B0009N1MV4/ref=sr_1_1?ie=UTF8&s=electronics&qid=1271188386&sr=8-1)" rel="nofollow"http://www.amazon.co.uk/3-5mm-Stereo-Soc…/a so it can be connected to my speakers but as soon as I turn my record player on a loud hum/buzz comes out of my speakers, anyone got any idea why this is happening or how to get it to work properly? Thanks