I found that the WA7 is quite sensitive to power. I live right next to a shopping complex so any time other than late night the sound is quite rough and unrefined when connected to the grid. On top of that, I have a pc that draws 650 watts (850 watt power supply) connected in the same room (1 powerpoint above my wa7)
I didn't quite believe that power conditioning would do anything for my setup before this experience, so let me get that out of the way first. I was always curious with the high end power cables but never got around to getting one due to the price and the fact that a lot of people disagree on the topic (I'll only make a jump if there is fairly unanimous opinion on something and its not a FOTM thing). This won't be a post about power cables by the way. I don't want to instigate a riot.
I found this quite accidently. During a blackout, the generic surge protector that I used got blown out and no longer functions. Luckily i disconnected my WA7 before and my pc remains unaffected.
I had to replace it and ended up getting a Belkin PUREAV from the local electronic store which had them on sale for 30 dollars each for a 4 point one. I got it just because I needed something reliable and robust- seeing as how I just experienced one frying in front of my eyes.
Relatively cheap. They were normally 60 dollars and over 100 at one point in time from what I understand.
When I got my WA7 hooked up and everything to the new surge protector though, I certainly did not expect the change in sound that I experienced...
Everything became marginally sharper and more well defined. Before the WA7 i would say was a warm, relaxing sound and while being engaging in its own right, did not exactly 'grip' my attention when it comes to the amount of detail it conveyed. The notes were also softer... now?
The sound are just so more.... Authoritative.
On later inspection of the packaging, turns out that the surge protector has some sort of emi/rfi filter mechanism which I suspect was the thing which altered the sound.
For a very cheap 30 dollar upgrade, i highly recommend something like this
I highly doubt a usb cable upgrade would change the sound characteristics like this. If I had to say- the difference is like 10%, which is huge once you've reached this point of diminishing returns.
The only 2 things which could explain this phenomenon would be
1) My old surge protector that i previously used with the WA7 was dodgy
2) The power being fed to my place is so 'dirty' that a bit of EMI/RFI filtering could have made a world of difference.