The PA 150 is a 12 volt DC, 1 amp power supply.
The PA 150B is a 12 volt DC, 1.5 amp power supply = 50% more current.
You can look up photos of each on the net to verify.
The manual states that the MODX draws 16 watts of power.
Using a simple power formula found all over the net:
12 volts @ 16 watts equates to a 1.333 amp draw - more than the PA 150 is rated50
2 questions:
Why is there so much misinformation about this?
And why is the PA 150B not available in the US?
I did find one on ebay for $51 though!
I bought an properly spec'd adapter on Amazon:
https://www.amazon.com/gp/product/B07G79KHQ3/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1