Triaxis humming on ld2 modes

[iceman]

I've been working through some ground loop issues in my setup. Finally got most things worked out but the last problem remains. I'm starting to think it may not be a ground loop. With my triaxis output connected to either my roadster or mkv's return and the triaxis separated from all other equipment I always get a hum on any ld2 mode(sounds like 60 cycle to me, and is not a hiss). All other modes are quiet. Lifting the ground of either the triaxis or the other amp, or even the cables, the hum persists.

So the question is, is this normal for ld2 modes (remember this is not noise, it is a hum. I do expect more noise on higher gain channels though). I searched around and found some other triaxis users complaining about this, while others didn't. I also didn't see any resolutions, including sending it to Mesa or a tech.

 

[crane]

Have you tried changing V4 or V2 tube ?

 

[gummx97]

Have you tried changing V4 or V2 tube ?

The most that folks here have tried with the triaxis besides tube swappping is cleaning the ribbon connectors inside the preamp. I had issues with my triaxis, eventually sent it to mesa after the tech guy i sent the preamp first was unable to troubleshoot the problem.