Sorry, to the average user, the paragraph above in the V20 help file about the Quad DAC is a bit misleading or confusing.
"Quad DAC - Enable this option to use any connected external audio device and optimize the sound quality using this menu".
To me, and I'm sure many others, I understand that to mean, that it will work with any headphone connected will trigger the quad DAC. The wording is misleading and the help file mentions nowhere that you need to have a set of headphones that have an impedance above a certain level to trigger the full capability of the DAC. On top of that, the B&O earbuds that were offered to many, do not trigger the full capability of the quad DAC, so to me that is misleading the consumer. It should be clearly stated in the literature (help files and specs) that you need high impedance headphones to take full advantage of the feature that was a very big selling point of this device.
David