https://www.futureshop.co.ukIMO the effect of "cable rolling": Amp to HP> Amp to dac> Power line> dac to source. Did some test on my friend's system. Although I wanna to try some cable rolling ,the cost of making mistake are still too high for me. And if I want to do so I would start with my primary system rather than with HD800 which just a secondary system to me. Maybe getting a cheap tube is better choice for me after all.
Have 60 days return right. Great cable store.