I'm thinking about putting a preamp in my 78 p-bass. I'm looking at either the Bartolini 2.2ap preamp or the John East P-retro. I like that the John East is easily reversible and can still be used in passive mode but I haven't really heard much about them. Let me know which one would be better or if you know of something else that would be good and not require any real modifications since it is an older bass. Thank you.