6 meters of balanced is ok to use with euphoria???

No problem especially with balanced cable, single ended it is getting long but also probably OK.

You will have signal loss.

The 22 kohm Zin of the X250 may be a problem. Talk to Sonic Euphoria....

I've got 3M XLR out of my TVC with no problem but I also have 4.2V out of the CDP and passive-friendly amps. The Cardas cables are about 40 pF/ft, correct me if I'm wrong, which is neither high or low capacitance. Something like Nordost Blue Heaven cables are low capacitance but are too revealing for some tastes.