My first c-004 was a big shock on my power amp. Stereo-image became very precise and clear, as if you listen to a master tape. What was lacking a bit was bass volume bit the increase in detail and realism… just incredible. I still wonder how this is possible with just an iec-plug.
With a Furutech FI-50 schuko I got that bass volume back and changing the iec-inlet on my amp for a Furutech gold iec-inlet also made the highs more silky and the whole thing perfectly balanced and natural.
I bought a second c-004 for my streamer+server. Now the effect wasn’t that spectacular as with the power amp, but still the c-004 gave clearly more detail and is worth every penny. Here a Furutech FI-50 NCF schuko brought some more bass detail and smoother highs.
So, the c-004 is a real bargain when you can get around the “not that strong” points like less bass with a power amp.
My cables are green and blue Furutech. This all combines very well for a reasonable price. Only the Furutech FI-50 NCF seems a bit expensive, but also is the p-004.