Hi Chris,
Thanks for the tips.
The constant buzz/beep tone is entriely different to mains hum, this is something I've never heard before.
I had an electrician install 3 dedicated circuits for my setup, 2 x 20amp and 1 x 10amp. The 568.2mm is on its own circuit so I can't see it being a problem. I've never had any hum from mains before so I can't think what might have happened, especially being one off.
I have the latest firmware loaded - 2.5b9 and the only change that I have made in the past few weeks is setting the precision bit from 24 to 16 on my CD, DVD and Game sources. I have now changed these back to 24-bit.
I'll have to at some stage open up the 568 to check for dry solder joints, which I didn't find when I first received it. I always open items, unless it is brand new to check the interior and take some photos for reference.
I have a spike protection circuit installed at the mains board but do not have any conditioners installed for any of my equipment. I have been pondering purchasing a PS Audio power plant, which some of you swear by but something further down the track to look at.
In saying that, I have had problems with the electrical spikes from the road in the past but that was all before I had the house re-wired and the mains board completely replaced and had protection devices installed. Haven't had problems since. It could be that dirty power may have come through and affected the 568. Who knows.
I think a good place to start off with would be to replace my cheapie DVD player. I am waiting for the new Oppo DVD player to be released and I am also looking at maybe purchasing a PS3.
Cheers
Pasadena.