Not suprising.Toslink is notorious for noise.If you are using plastic,change to glass.Keep the cable well away from AC power sources and cables.Better yet,if possible, use coaxial connection.Why did you change from the USB cable,that should be the best connection?In my bedroom system I have to use toslink because that's the only digital out my cdp has,bummer.The glass cable cleaned the noise up a lot.Good luck.
