MauricioIt certainly looks like it would work with K7xx but they don't show the output impedance. At the $159 price it looks good which is cheaper than I can buy it in China. I wish there were more English language reviews about this unit. At the $199 price, I would choose other products.
this unit: https://www.massdrop.com/buy/matrix-mstage-amp-dac actually looks better for power because of the output impedance of 5 Ohm