My FR10 has the same hiss. Before I bought last summer, I read EVERY post on the web about the FR10/12, and a lot of people talked about the hiss. The conclusion that I took from reading those posts was that it does a have low level hiss inherent to the circuitry, but it's not a problem in real life playing. Sure enough, when I got mine, it was there. As soon as I flick on the power, there is a low level hiss, kinda like some old radios or phonographs I had as a kid. It's not a problem for me, it just let me knows the unit is powered-up. Soon as we start playing it's gone and not noticeable at all. I'm all electric so that could be a part of it. If playing super soft acoustic it might still be there. While the idea of it -- a low hiss -- bothers me, in practice it's so low it doesn't bother me, and I pretty much don't even notice it anymore. I've never heard anyone else comment on it. Overall, I love the FR10. So light and sounds great. Hiss non-issue for me. Having said that, if they get rid of it with a firmware, I'd be happy to delete hiss.