Skylab
Reviewerus Prolificus
Those numbers don't mean anything without knowing what tube tester they are from and what that testers target numbers are for a 6SN7.
But regardless, if the tube is quiet and sounds good otherwise, I don't think what you describe as a lack of bass weight is anything more than the way that tube sounds in the amp you are using it in.
But regardless, if the tube is quiet and sounds good otherwise, I don't think what you describe as a lack of bass weight is anything more than the way that tube sounds in the amp you are using it in.