I just bought a 'matched' quad of winged =C= 6L6GC's. When biasing according to the Weber tables, average is 38ma, while hot is 44ma for my 475 volt amp. With this quad, I can set 2 of the tubes at 40, while 1 reads 36 and the other 44. Will this amount of variation be harmful to my amp? Harmful to my tone? I tried switching heads around on my bias rite with no significant difference. Also, right now I have the outer pair with the big discrepancy. Will I get any benefit from swapping an inner and outer tube, making the 2 working pairs more closely matched?