sorry it this has been discussed. has anyone here replaced the preamp on their Fender American Deluxe Jazz bass with an East J Retro Dlx? I am a huge fan of the East pre's (and John East is such a nice guy !)- i have the U retro on a bass and love it, now i await a Fender Am Dlx Jazz and wonder if there is a definite advantage to investing in a J retro for it. Anyone?