No, I don't get that level of hiss with the Earthquake. I did gain match like you suggested before I ran Audessey. After I ran Audessey, I moved the gains up on the amp just to see what would happen, and that's when I got a great deal of hiss. Like I said, with the gains set at around the 2:30 position I don't here any pronounced hiss.
So, according to Chris, if I here such a hiss, no matter the gain setting, I need the S-Convert, but are you saying I shouldn't use it if I don't here the (pronounced) hiss at the 2:30 setting?