Hi Guys, I was hoping someone could offer some advice on this issue. The problem is my tweeters in both left and right channel give off a quiet hiss, in between tracks or during pauses between notes it's fairly prominent and during general music it's harder to pinpoint but definitely having an adverse effect on the overall sound. I've not had to issue in the past but am still struggling to identify the source of the problem. My system is a Laptop running Squeezebox server, Squeezebox Touch > Beresford Caiman > Quad 909 power amp > B&W 602 S2 / BK XXLS400. The issue is a new one and I have recently got rid of my old Arcam integrated amp and replaced it with the Quad. The Quad is a brand new amp though. I had thought it may be the DAC causing a problem so last night tried the Touch direct to the 909, the hiss definitely got quieter but is still there. I've checked that all the cables are secure, doesn't appear to be anything wrong there. I have thought the lack of a dedicated pre-amp might be an issue, is this plausible? Could my electricity supply be to blame? Could it be cables crossing behind my cabinet? (Never been an issue before) Could it be the Quad? (brand spanking new though).