A new computer system? Did you build it yourself or have a professional DAW builder? You can have the newest, fastest modern computer and it might not perform as well as a 7 year old quad core DAW, if it has not been fined tuned and optimized for the needs of real time audio processing. Have you disabled USB Power Management (all
USB Root Hubs), from the "Device Manager"? Really important tweak for the Apollo Twin USB.
Check out this UA video about "Optimizing Windows for Audio" for more info on this and more:
http://www.uaudio.com/blog/optimizing-windows-computer-for-audio/ Also check out post #27 from the UAD forum link below for tips on optimizing for real time audio processing . Do watch the linked video in the post about how various devices/drivers can have a detrimental affect on real time audio processing performance in a DAW and the reasoning for doing so. Several posters in the thread already found the solution to their crackling in audio playback after watching the video and doing a bit of trouble shooting.
http://uadforum.com/support-troubleshooting/21696-apollo-twin-usb-crackling-my-monitors-3.html PS: you will probably get a lot more "focused" feedback on any Apollo/UAD issues directly from the UAD forum.
If you have not already, check out the plethora of support information on the UA website:
https://help.uaudio.com/hc/en-us/categories/201163633I installed my new Apollo Twin USB last weekend and have it is rocking on my 2 year old custom built DAW on Win 10 Pro x64 with all of the latest updates. Working solid with SPlat x64 (Newburyport). The latest SONAR update even fixed a reported bug that would crash SONAR when deleting multiple UAD plug-ins from the FX bin. So all is good now!
Hope this helps,
Billy Buck