I would mark the tubes so you don't confuse things when moving them.
The Se change from bal is also my thought.
But don't move tubes as well.
Pick a process and one step at a time.
What ever you do write the process down.
Maybe its just me but I get distracted and confuse the process .
Start with the small tubes since there is only 2 of them.
Tubes that develope noise either start as they get warmed up or when on a long time.
Warm up is better then noise when fully hot.
The Se change from bal is also my thought.
But don't move tubes as well.
Pick a process and one step at a time.
What ever you do write the process down.
Maybe its just me but I get distracted and confuse the process .
Start with the small tubes since there is only 2 of them.
Tubes that develope noise either start as they get warmed up or when on a long time.
Warm up is better then noise when fully hot.