VenricoreI didn't clean anything, the only thing I did was set it to high gain using the access slots on the bottom. If your tubes aren't lighting up could it be a power issue? Mine gets hot.
VenricoreThe only other thing is it is plugged into a grounded surge protector. The grounding might be important. I’ve heard it is sensitive to that and also sensitive to electromagnetic interference like WiFi. That’s all I know.
BIGGUY4x4It's a completely different experience. The O2 would be for a neutral "reference" sound. The Little Dot is going to give you the tubes experience. I have both because I like to compare, and for some sources I prefer one or the other.