I think one should first determine whether they prefer tube or SS; which would of course be sighted, and then go from there.
I would never go double blind because I'd want to know every detail about whatever it is I'm trying to decide on.
Double blind test- over a month- could this be a reliable test for any equipment?
I am aware there are lots of debate about the merit of the double-blind test.Reading lots of articles online makes me feel overwhelmed and also confusing- you could have a totally opposite view of the same piece of equipment and system.