Hi there

I also have a 598/568.2 combo and do hear sound quite load 'clicks' BUT only when loading a CD after.

This does not happen all the time but I would 50% of the time, dont seem to get any other noise at any other time though.

So not much help to you be that my experiance, apart from that I find the combo very,very good and I'm very pleased with my system.

Skooby