Ron, I'm using an AKGC3000 Condenser mic powered by a Nady SMPS-1X Phantom Power unit and hear no hissing sound either thru headphones (Sennheiser HD650), or thru my custom PA setup (Logitech Z5500 PA). In fact, it's pretty much dead silent. IMHO, the mic thru the vocal harmonizer sounds clean & stellar as well. I set my Tyros 4 mic gain knob at around 11:00 and the MIC Default Balance at 115, and the Style Vol at 90. I then adjust 'all other' panel parts (LEFT, RT1,2,3) in relation to those settings.
Ron, feel free to PM me if you need further info or assistance. - Scott