This is the first blackface fender I have had in nay years. Its very warm sounding, but I feel like it could sound better. Its almost like the mids are too pronounced. The previous owner replaced the 6L6's with KT66's and the speakers are Naylors. I plugged it in to a cab with Weber Californias and thought it sounded a bit better? Do you think I should change the speakers? Also, what about the tubes. Would 6L6's produce a warmer more fendery (less mids) sound? Also, if I put 6L6's back in it, does it have to be rebiased?