The mixer is new, and if I bypass the ua-5, going straight to my jb3, it is maybe ~.1 db difference, I used a white noise track to verify, but It was very noticable in the field. a full 1 DB is a pretty big deal. While testing I also used/swapped different connectors annd also tested the jb3 optical in with the same test tone. I'm sure it is the UA5, I just never noticed it because the old mixer had l/r main faders and only a 5 seg VU. I can just adjust my mixer on each channel, but that is a pain in the ass and it is rendering my main VU on the mixer useless.
Matt