I answered already but you either missed it or are stuck on the math. Use the calculations ONLY as guidelines. You HAVE to use your ears or the bias process is a waste of time. There is NO tone to "70%, or "60%", balanced or imbalanced. Those numbers exist only to develop general guidelines and "safe ranges" for tube types. They have nothing at all to do with sound. To repeat - bias based on an average - and it's arbitrary. Use 70% dissipation as the center point, or 65%, or whatever. Then ***play at normal volume and adjust the bias a few ma in each direction. Find the "sweet spot". Then STOP*** Check to make sure you're in a safe range for the tubes. If not, your tubes might be shot, because it will probably be fine - maybe a bit on the hotter side if you're like most players. Then you're done. The difference between the two tubes is immaterial, really, because (as I and several others already noted) the driver is rarely balanced anyway. That makes i impossible to precisely balance "matched" tubes. Anyway - it sounds like you're hung up on the math. Don't be. Use your ears and only use math as a VERY loose guideline.