John Paul Jones is one of my favorite bassists and his Fender Jazz through an Acoustic 360 is probably one of the best Bass sounds ever. I know there is debate whether he used flats or not but after using Rotosound 77 flats, that is his sound and he stated in an interview he used them on his jazz and the swing bass on his 51 p bass. Listening to bootlegs from the 1977 Led Zeppelin tour when he switched to the Alembic 8 string and Bevcar 4 string active through a GK GMT 600 head and the Acoustic 361 cab is one of the worst Bass sounds he ever had. He used a Hagstrom 8 string through the Acoustic in Presence and had a good sound. His sound didn’t improve in 1979 and 1980. I just don’t know what he was thinking with that sound.