It's a new abbreviation to me: Device Firmware Upgrade. So yea. Glad you could get it working.
Of course it worked straight out of the box and I was happy for a few hours, but I have power hungry Sundara's and needed to get into full power mode (make that the default for heaven's sake) to hear those new HP's sing.
In retropsect, It is kind of slick--like getting into computer BIOS where it looks for a hot button during initial boot up and never thereafter, and thereby protects against an accidental change of settings. But yes, instead of saying powering up, why not "hold button down while attaching the power supply." Like me I'm sure you tried pushing the damn power knob every which way to Sunday. I managed to get if to even hang up a few times, requiring that I reboot it, but not realizing that what was meant by power up. Now of course all makes sense. That it sounds so good for such a great price makes this sin forgivable. I did send a note to Topping, which likely got round filed, and the guy shaking his head, saying dumb Americans.