You need to be VERY careful using cheap wall warts on something like a decent LNA.
You may have Voltage drop to the LNA which should be mounted at the base of the antenna and the cheap wall warts are NOT typically regulated, they usually have a high open circuit Voltage and only are close the rated Voltage when the wall wart is loaded down close to the make current/Wattage rating.
Funny how you were turned on to that specific LNA as I recall getting a LOT of push back from a number of members here on this forum.
Suggest you really should read this thread if you have not seen it from Dec 2016 with over 4000 views, but few comments or feedback if anyone has implemented a similar set up.-
https://forums.radioreference.com/s...mp-10-off-december-other-useful-rx-items.html
While my set up is linked in a post in that thread, here is the direct link so you can see how I set up the Voltage regulation AND the FM Broadcast filter which you will likely need. I had to have a VERY high rejection FM Broadcast filter to clean up the overload on the LNA.
https://www.dropbox.com/sh/hmvxvtev71z09z8/AACpt0RSsfk5BI5T2JD0WOfNa?dl=0
I tested A LOT of LNA's and different configurations and at the end of the day that Mini-Circuits LNA was one of the best performing out of everything I tested. If you cannot get an improvement in your stating using this LNA, chances are you have an implementation problem, require some input filtering and some output attenuation.