I have a boutique power block and cables, my power block is a 6 way silver plated block with 2metres of lapp 2.5mm2 cy cable ,a huge ferrite clamp, a silver plated mk plug and 13 amp hi-fi tuning pure silver gold plated fuse , the difference it made to my equipment was it removed all buzz/humming because the cable has it's own ground loop, with my tv equipment plugged into it i do get a slightly cleaner picture, my power cable is a markgrant dsp1.0 this made a quite a difference, less speaker hiss and a more fuller sound but the system i use it on is nothing great it's the edifier s730 a proper high-end amp will have much better power conditioning and caps and probley won't benifit so greatly from a custom cord, out of all my power based equipment my best buy was the hifi tuning UK Gold 2 Audio Grade internal fuse, in the s730 the bass gained lots of defention the sub really sped up and can deliver bass with alot more precision than it could before, also the difference is sound seperation and stereo imaging has huge, the fuse was only £25 half the price of the power cord a third the price of the extension block, yet made the biggest most noticable difference, i wouldn't bother too much with d.i.y powercords unless you have speaker hum/buzz/hiss , the difference in sound isn't worth there huge price tags, i would highly recommend you try a hifi tuning equipment fuse.