I can't speak for Krell amps. All I can say is that with my amps there is no noise. Silent is silent. You can't get more silent. Maybe I lucked out with my choice of amp? Maybe it's my power conditoner? There simply is no noise. Personally I don't think it really matters until you get an improvement of at least 6%.

[q]If you don't care about FM, MRC, Toslink, Balanced Outputs, Firmware upgrades, 6 Channel Analog input, potential HDMI. Then get a 568. It depends on how much toy money you have to spend and how important High-End is to you[/q]

With all due respect, I sure hope you aren't implying that desiring the features you listed is some kind of proof that one is serious about high end. Or conversely that one who choses the 568 is not serious about high end. FM is not high end; Toslink is irrelevant if you are running coax; MRC is dubious as noted by running tests and getting different results, neither are the results night and day; balanced outputs are not a prerequisite to sublime performance, 6 channel inputs have very little to do with high end (not without pass through), HDMI is a bonus - not a prerequisite and firmware upgrades - well you know how I feel about that.

Meridian has been making outstanding products for years, and each new product has introduced marginal sonic improvements over the next IMO. This is probably the primary reasons why you see them messing around with projectors, switches, receivers, integrated units and the F80. I think most of their clients are wedded to their gear for many years to come. This certainly is the last processor I'll be buying for the next 5+ years. They probably need new products to maintain their revenue stream. It's the curse of having been great at what you do for some time.

PS: I already wrote that my mains go down to 20hz, and that with my sub wired in parallel my system goes below 20hz.