Alternate Input Hiss and distortion FX Loop

    Hey guys, i ve just realised there is a known issue with some units, in the "alternative input" jack.
    There is a huge amount of hiss, horroble distorted noise on my unit.
    I ve came across some posts of people with the same problem, and most of them knew the problem was with hardware.
    My problem is that i cannot wait for support...I live in Brasil, and i imagine it would be like weeks wihtout the unit.
    So...Can i use the XLR as alternate input for the FxLoop?
    I need stereo fx loops for my Timefactor delay...
    Anyone???
    Thanks

    BTW: I tried all possible input/output configurations in the software...But i could not get the hiss to go, so i KNOW its the alternate input jack!!!

    Are you using current software?
    When you use Loop Stereo with Return and Alternative In as stereo returns, is there no "hiss" on the Return? What if you exchange the left and right plugs? Still hiss on the same side? Or on the other side now?
    The TS/Return is one mono input, which cannot be used as a stereo return.
    Is there any other function enabled occupying the Alternative In? What is selected as Input Source? Is Aux In cranked up?
    What if you just loop in a patch cable between Send and Return and the Send and Alternative In?
    What if you use Alternative In as a guitar input (Input Source = Alternative In)? Is there also hiss?
    What if you use Alternative in as Aux In together with Return? Is there also hiss just one side?
    Have you tried other cables?