OK thanks for the technical clarification.No. A triode is not a constant-current sink. When the upper triode receives a positive on its grid, current increases, as well as Gm, and Rp decreases. At teh same time, the lower triode sees its plate voltage increase, as do current and Gm, for a decrease in Rp; this tends to linearize operation. Not as much as in a true push-pull, though.