I'm reading a lot of conflicting information about this. If I can't find a matched quad of, say, a particular brand of 6922 input tubes for my ZMA, is it crucial or significantly desirable to have all four tubes matched in the sense that they all test the same on the Hickock tube tester or whatever it is that people use to test such things? If I find four tubes of the same type and/or manufacturer and, theoretically one is at 90%, one is at 75%, one is at 80% and one is at 88%, does it make a difference if they're all running in the ZMA at the same time as long as the power tubes are bias matched on the meters?

Good reminder. The manual is more specific than I remember. Thanks!