If the ua5 stops sending the signal the JB3 will not lockup it will record a second about once a minute.
Could have been heat related on the JB3. If you had to reset the JB3 the file is toast
The JB3 will stop if it quits recieving a signal via the optical in. I had my cable come loose on me once and the JB3 stopped. I hit record again and it started a new track no problem. As it turned out, the JB3 "stopped and saved" the file when it lost signal. Lost about 5 minutes of music or so??? I was in the bathroom and I think someone accidentally kicked my bag...
If your JB3 overheats, it will just shutdown. Or it will show you the "overheat" screen. I've never had this happen at a show, but have it happen at home when I'm doing a ton of transferring. I'm not sure what happens to the recording at a show if you overheat...
And yep, as far as I know, if you reset, and didn't get a good "stop and save" your file is toast...
Terry