Did you read Sony's description?
They said they used a copper case because it enhances overall acoustics and sound quality.
http://www.sony.com/electronics/walkman/nw-wm1z
"[size=17.03px]Discover the functional beauty of oxygen-free copper[/size]
The NW-WM1Z is fully encased in a high-grade gold-plated oxygen-free copper chassis. Widely used in instrument manufacturing, the copper lends the player its unique natural, acoustic sound. Its conductivity and raw strength reinforce the Walkman® with unrivalled audio performance."
This is the same thing which you can find on AK380 Copper's description.
iRiver is charging $3999 for AK380 copper... while copper is even cheaper than stainless steel or aluminium.
I found it to be surprising that Sony is comitting to this. Sony has Playstation, headphones, CD players and other legitimate businesses. They're real guys but now they're committing to a snake oil audiophile business which doesn't have any scientific foundation.
You seem surprised , but Sony has already used this kind of nonsense in the past.
Don't know if you remember the Sony micro-sd card "designed for music", with lower electro-magnetic interferences leading to better music quality.
Same idiocy than saying that the chassis plays a role in SQ.
Reducing interferences and getting better EM insulation are good things for sure, and they play on this to make ambigous statements.
Look at the sentence, they say "audio performance", which could mean pretty much anything or nothing.
In the end, you're completely right, using copper for a chassis is just a disaster for the customer, because copper oxidizes quickly and is quite soft, so it will get damaged quicker.
Grounding doesn't require an extremely conductive metal, so having a aluminium or steel makes much more sense, and you can always improve the shielding efficacy by applying copper or gold threads/lacings inside the chassis. Aluminium-unibody smartphones already provides extremely good shileding and aluminium is much cheaper/easier to manufacture.
Pure marketing, but hey, A&K has sold a 3500$ DAP, followed by Cowon and more recently Opus (model 2), so why not Sony... They sold a 1200$ ZX2 in large quantities, so what's stopping them to increase pricing ?
Certainly not the 100 "rich" Head-Fiers believing in anything in the name of "SQ-god".
