Mine has serious noise issues but I suspect it is due to a faulty AC adapter. This thing is very high quality throughout but the AC adapter is pretty chintzy so I am going to call Sweetwater to see about a replacement.
What type of noise is it?
I only used mine twice in a live setting and one of those times I got a nasty hum when I plugged in the DI. On that day, I quickly switched to the 1/4 inch out into a separate DI to avoid the hum because I didn't have the time to investigate what the root of it was and that avoided the issue. The other time I used it live, I didn't experience this issue.... however.....
Mine is currently back at Trace headquarters for warranty as I was experiencing significant volume and low end content drop / loss when engaging the compressor (even with the knobs fully counter clockwise / off) as well as low end loss when engaging the drive section....
They've had it a couple weeks and I haven't heard anything.... I've sent them an email and left multiple phone messages but they haven't replied. I just keep getting their voice mail....
As a bonus, the Drive on the Transit B is actually fantastic sounding and extremely useable as opposed to the dismal sounding ones in my Zoom units. I also love how each particular Compressor/EQ/Drive sections are well organized and the LED indicators are not only very cool visually, they also serve as an easy visual to what is engaged (or not) on the unit.