Main out-put reverting from Vestax to Built-In output during play. Suggestions?

Hi! Any idea why the Main output should be reverting back to the built-in output during play? After opening djay and plugging the Vestax Spin 2 (via the USB cord) to my MacBook Pro, I confirm that I want the Main output (and pre-cuing) to be the Vestax Spin 2–which is connected to a separate amp, etc. Everything works as expected for 5, 10 (maybe 30) minutes until–for no obvious reason–the main output reverts back to the built-in output. All sound to the amp is killed, and the output is suddenly is reverted back the MacBook’s speakers. Any suggestions?

For a time, there seemed to be a correlation between running iTunes and djay; if I booted up my MacBook and made sure NOT to open iTunes, the main output problem more or less disappeared. Now the reversion happens constantly. I can’t keep output to the amp for longer than a few minutes. So for the moment, I’m grounded: I can’t trust djay to play gigs. Help!

As we’ve discussed via Email, this problem is due to your Vestax Spin 2. Please kindly contact your seller in order to get your controller fixed.