Thx for answering
1) Yes . When TF is in amp's loop effect both switches are down. Nothing changes though.
2)Yes. I'm using 220V Eventide power supply.
Even when I play only with this effect, still low hiss is present. Since I susspect that it's just the way it is I'm also trying to get some help from low voltage technician. Changing suspension leads ,pluging to different power sources, receptacles didn't help. By the way, is anyone having the same problems with TF or other devices?