If you are plagued by hums, get a DTI in your signal chain. With a pair of transformers that have a "flat and wide frequency response and can handle high signal levels while maintaining an isolated balanced output" the DTI seems to good to be true.
Includes 2 x XLR, 2 x 1/4" phono and 2 x RCA for I/O.
Passive design for trouble-free use.
Check out the ART Pro Range here.