This has probably been covered, but is there a US/North America release date set yet?
Sorry, this thread is so long, and I researched their site and the web and could not find that info.
Apologies if you read it that way.
I went back to look into this. You can hear it when you stop the music I then cranked the volume way up and simply plugged the IEM's in and out to see if this was real or not - it is.
After you lock in on this frequency you can turn it down and you can still notice it. Not annoying and sticking out though especially when the music starts.
DX90 will be out in a couple of months or so too. If it really does improve on the DX50 , it will be quite special. They've ironed out pretty much all of the gremlins in the firmware now too, so should be pretty smooth right out of the gate...