Tuneslover
Headphoneus Supremus
Just replaced the stock 4490 power cord with a Pangea Audio AC 14SE MKII Signature Power Cable ($50).
It was hard if there was a difference at first (if any), there was nothing super obvious, but after playing a few songs I realized it just sounded more "musical" and "authentic"... then I realized there was slightly more instrument separation, and sonic ease. There was an "edge" that was removed that wasn't all that apparent until it wasn't there anymore. The music felt easier to listen to. The sound was slightly smoother/more liquid.
I didn't realize power was such an important aspect of audio until I got a power conditioner and now this cable. You can seemingly improve a system for very little cost... my jitterbugs cost $50 each, the power conditioner I got for around that price on ebay and the Pangea was $50. The Shunyata Venom power cable is supposed to be better, but it's a bit more expensive.
I have a Pangea AC9 power cord on my NAD BEE C326 integrated amp and it super juiced this amp!