What are you using for music playback? ITunes? The best computer playback performance is attained when you can optimize the computer playing the music, and when you can dedicate the computer to only playing music. What operating system a you using, there are several guides created by various DAC manufacturers that tell you how to optimize your system for music:
http://www.benchmarkmedia.com/wiki/index.php/Windows_7_Audio_Playback_-_Setup_Guide
This is one example.
Audioengine is a great brand to start with, they also have a USB DAC you might want to try.
I think your playback problems might have more to do with the setup on your computer than the DAC you are using. TIP: If your music library is on an external hard drive, and you are using a USB DAC, try to use a firewire external drive, having both the drive and the DAC on the USB bus might overload the computer's innards and cause the problem you've described.
Computer audio takes some tweaking, but it's very rewarding when you get it working! Don't give up!
http://www.benchmarkmedia.com/wiki/index.php/Windows_7_Audio_Playback_-_Setup_Guide
This is one example.
Audioengine is a great brand to start with, they also have a USB DAC you might want to try.
I think your playback problems might have more to do with the setup on your computer than the DAC you are using. TIP: If your music library is on an external hard drive, and you are using a USB DAC, try to use a firewire external drive, having both the drive and the DAC on the USB bus might overload the computer's innards and cause the problem you've described.
Computer audio takes some tweaking, but it's very rewarding when you get it working! Don't give up!