Disagree with leoinstereo...
If you bias unmatched tubes to the same grid current, the same grid current will not mean the same offset point on the tube's output characteristics another words for one tube it could be too much and for another is too little...
If you bias unmatched tubes to the same grid current, the same grid current will not mean the same offset point on the tube's output characteristics another words for one tube it could be too much and for another is too little...