Last night I modded the tone control in my Mexi Jazz bass and it sounds so much better. By just changing the 50nF tone cap to a 70nF it sounds 10 times better. I was always bummed rolling the tone off when you could still sort of hear some metally string sounds when I just wanted to hear a nice fat sine wave type sound. Switching the cap gets rid of the muffled sound and gives you a nice bassy tone. Try it if you dare!