New system with periodic sound dropouts

As with many computer-related issues there are countless possible causes, but I doubt that power quality is a factor in this case.

If a wireless link is involved, as suggested above interference on the channel that is being used is certainly a possibility.

What specific make and model is the computer? Does it have a mechanical hard drive or an SSD? Is the music stored on the internal drive that is utilized by Windows and the server program, or on a second internal drive, or on an external drive?

Also, what anti-virus program are you using, and have you tried temporarily disabling it? Some anti-virus programs can slow a computer significantly.

Also, if you already haven't, under the Start icon/Settings/Update and Security/Advanced Options/Choose How Updates are Delivered, change the default setting of "on" to "off." Otherwise, as stated on that page, "your PC may also send parts of previously downloaded Windows updates and apps to PCs on your local network, or PCs ON THE INTERNET" [emphasis added], which among other conceivable issues may intermittently slow down your computer.

Finally, your reference to "the last 2 months" brings to mind that the major "Anniversary Update" to Windows 10 was probably automatically installed in your computer during the month of August.  If the computer and DAC combo was working properly prior to that time the Anniversary Update, which caused a variety of problems for many Windows 10 users, may have been a factor.

Regards,
-- Al
 

My computer is a Dell Inspiron 3847 desktop connected wirelessly to AT&T’s network. The Microsoft Windows Update came through 9/30/2016. All music is stored on the internal hard drive.

It looks like your computer probably has a 1 TB 7200 rpm mechanical hard drive. One thing that may be worth checking is the fragmentation status of the drive, and if Windows has been automatically defragmenting it on a scheduled basis.

Type "disk defragmenter" into the search box at the lower left corner of the screen, and then click "defragment and optimize drives," to open the defragmenter program that is built into Windows. Given especially that your computer has probably had at least two major Windows updates (from Windows 8 or 8.1 to Windows 10, and the Windows 10 Anniversary Update), as well as the usual updates that are issued each month, if the defragmenter program isn’t set to run on a scheduled basis the files on your hard drive could be highly fragmented (meaning that individual files would be broken up into many different physical locations on the drive), which could be contributing to the problem.

Also, it looks like your computer has both USB 3.0 and USB 2.0 ports. It might be worth trying whichever of them you haven’t been using to connect to the DAC.

Also, your computer was apparently offered with a choice of various amounts of RAM. If it has only the minimum 2 gB installed I would definitely suggest replacing or adding RAM to increase the total to at least 4 gB and preferably 8 gB.

Regards,
-- Al

Good!  The two bottom-most USB connectors on the rear are the USB 3.0 ports, and the four above it are the USB 2.0 ports.  See the diagram on the second page of this Quick Start Guide.

Good luck.  Regards,
-- Al
 

A simple way to determine if the wireless link has anything to do with the problem would be to see if dropouts still occur when the computer’s wireless adapter is disabled in Windows.

To do that right-click the start icon at the lower left of the screen and then select "Device Manager" in the menu that appears. In Device Manager expand the listings under "Network Adapters," then select (highlight in blue) the entry corresponding to the wifi adapter, and click the button at the top which says "disable" when it is pointed to. That button will look like a black downward pointing arrow at that time; when clicked it will change to an upward pointing green arrow that would allow you to re-enable wifi at a later time.

An entry will probably also appear under "Network Adapters" for the Bluetooth wireless function you are apparently using for your keyboard and mouse, as well as an entry corresponding to the wired Ethernet port (most likely referred to by some other name). Those should not be selected when you click "disable," of course.

Good luck. Regards,
--Al