hissing on the monitors?

[where02190]

Even if the monitor input is -10dbV, it's still not even closely compatible to the mic level or impedance of the DI output. However most pro monitors have +4dbu inputs that can sometimes be switched to unbalanced -10dbV inputs, making the mismatch even worse.

There is a specific transformer that is used for this, it is a 1:1 iso transformer, as I previously stated. However it is the last thing you want between your audio ande monitors, as they are anything but transparant, making those expensive control room monitors very inaccurate.

The solution is to find the source of the ground loop and correct it properly.