Ok, have had the AD20 out a few times and I am not sure that I am happy with the noise floor where I need to set the mic gain. With the SP-Preamp I don't think I had as much hiss. The part that sucks is the detail seems to be greater on the AD20... This is running the gain between 1/2 and 3/4. Anyone else seeing a fair amount of hiss with the gain set there? If I run the levels between 1/4 and none, there is NO hiss...