Have you tried moving the Deckard/King or nearby components to see if it's a Radio Frequency Interference issue?
Sometimes there may be something nearby (a modem/router, computer, DAC, disc player, cell phone, refrigerator, AC unit, etc) that's emitting RFI and the amp is simply amplifying it.
There may also be a USB or interconnect cable picking up noise from something it's passing by, so we recommend re-dressing and/or changing cables to check for that issue as well.
Sometimes there can be a peripheral such as a USB hub or other device that generates noise when plugged into a port on the computer, so we recommend removing all peripherals that aren't needed to see if that solves the issue. The same can be true of Apps that are running and not needed: we recommend closing all unneeded Apps to see if the noise abates.
We've also discovered that certain computers even generate noise, so if it's possible to see if a different computer or portable device eliminates the issue, that may save us all some trouble.
Does the noise appear even when nothing is plugged in to the amp's inputs?
If it doesn't, then it's likely that the noise is being generated elsewhere and the Deckard/King is amplifying it. In this case your challenge will be to find the source of the sound and eliminate it. You can also try plugging the amp into a different electrical outlet (in another room is best, you can use a good extension cord if needed).
About 99% of Deckard/King noise issues are not due to a faulty amp and are solved by following the advice above, but if the amp does prove to be at fault we'll be glad to help. In that case please send us a message via the “Contact Us” form here: https://www.audeze.com/support or email us at firstname.lastname@example.org and we’ll take care of you.