AES Journal Forum

This paper was written when computer modelling was a brand new technology and when even transistor models were comparatively crude simulations based on a few constants and the Ebers-Moll equations.  The whole notion of trying to simulate a vacuum tube system electronically was just totally off the wall.  People weren't thinking about trying to emulate the sound of tube circuits back then, they were just looking for a simple tool to help designers.

So, this is a simple first order model that merely describes triodes and pentodes as linear functions.  It doesn't include Miller capacitance.  It doesn't include any weird leakage effects.  It's based entirely on a model of function, not on a model of the internal physics.

But it exists.  It was totally off the wall, coming at a time when there was little to no serious interest in tube circuit designs, and coming from an academic who had a history of working hard to eliminate tubes by finding and solving aberrations in solid state circuits.

You'll find this paper cited by anyone who is working on simulation of tube systems because it was the first, it came out of nowhere, and it made people realize that it was possible.