I just bought a used Simaudio Moon Evolution i-7 integrated amplifier and I have an audible hiss from my speakers when I turn the amp on. It's not distracting when listening to music but it is much louder than the hiss I used to get with my NAD M3 integrated amp. The volume of the hiss does not change with different volume or source settings on the amp. I'm wondering if there is a problem with the i-7 that I need to get checked out or if it's normal. Simaudio says there can be a more of a hiss with their products than some others due to their "no feedback" Linx design, however I've heard others say the i-7's noise floor is extremely low with very "black" backgrounds. Ultimately I just want feedback as to whether this could signal a problem I should be concerned about and if I should see my local Simaudio dealer.