Rudolf has published earlier articles in Linear Audio related to finding the lowest distortion solution for an ultra-linear circuit. However, on closer examination it turned out that his solution provided the most linear anode characteristic, which is not the same as lowest THD. In this article the author leads you through his investigation and the hidden arguments why the lowest THD is achieved at a certain screen grid tap. Comparisons are being made with historical publications as well as real-world tests on a curve tracer.
An investigation of the screen grid tap - a search for the hidden arguments