Already opened a support ticket but wanted to share in hopes that someone has figured this problem out.

I used an 57MKII for the first time last Thursday. The opener had no issues with the mixer or Serato DJ. I plug in the mixer's second USB with Serato DJ open and the virtual decks appear (was not prompted to install drivers and restart). The first 15 minutes went fine. Then the sound begins to distort on the Main, Booth, and Headphones from both decks regardless what mode I was in (using 1200s w/ internal ground) . It sounded like a bit crusher effect that was being redlined, pretty awful. The distortion wasn't immediate. Hardly noticeable at first then deteriorated over about 30 seconds to terrible.

I plugged my phone in the Session input to play a song and it sounded fine. I restarted Serato DJ and it worked fine for another 20-40 minutes then the distortion came back and I played a track from my phone. This happened 10x through 10pm-2am!! I was on my phone buying tracks that I could slam. It's beyond me how I was able to keep the crowd unaware and for the most part content.

While my phone played music I tried trouble shooting by switching USB inputs and USB cords but neither worked.

I've been using Serato DJ for 3 weeks without any issues on a number of setups. SL4 w/ 900nxs & 1200s, 62 w/ 1200s, 62 w/ CDJ900s in HID, SL4 w/ 900nxs & CDJ2000nxs in HID.

Since last Thursday I installed the driver for the MKII. I'm playing at the same venue tonight and will arrive early for some testing but will use my 62 until there is a definitive diagnosis/solution.