what causes the sss in words like 'thisss'?


I run apple lossless codec -> airport express -> recently purchased musical fidelity x-dac & tube buffer -> rotel 1056 receiver -> Quad 22L floorstanding speakers . I have also tried a cheap cd player source but no luck.

So what causes those annoying sss sounds in words? Source? Amp? interconnect? I'm considering returning the musical fidelity stuff and spring for a naim CD5 and nait 5i combo. Thoughts?
Ag insider logo xs@2xmonstachuck
It's called negative sibilance and it's almost solely a result of dirty AC from the street coming to your home. Dirty AC can also come from your appliances, dimmers, and your digital dac or cdp.

However, proper line conditioning can fully resolve this issue and more.

-IMO
This weekend I got a naim-recommended power strip - the wiremold L10320 - http://www.naimusa.com/2004_site/html/power.html

Is there a power conditioner you'd recommend instead?
Congrats, you have a great system. I noticed the same thing with mp3 sources. I think its a poor source coupled with high resolution playback where you have no high frequency rolloff.
Sorry, I forgot to mention that proper line conditioning can only rectify the negative sibilance induced from dirty AC.

Obviously it cannot eliminate negative sibilance permanently recorded into the medium.

-IMO