I recently put in a pair of 9j1 in my MIM fender jazz. First time i played with them i was amazed at the tone but when i played with the band i noticed the output was very low i had to pretty much double my gain and even then i would get lost in the mix. I was wondering if there was anything i can do to bump up the output. I was told that installing a preamp would do the job. is is this true?