About this page
Every part is generated in code from dimensions: no model files. The valve follows the 12AX7’s data sheets; the stage round it is the textbook one (250 V supply, 100 kΩ anode resistor, 1.5 kΩ cathode resistor). The parts inside the bottle are in proportion; the grid’s wire is drawn thicker than it is so it can be seen.
What you hear is real. The valve’s curve is computed from a published triode equation on that stage’s load line, with the grid drawing current once it goes positive (a real grid starts a little before 0 V); the transistor stage copies its input until it reaches its 9-volt supply. The same table shapes the sound, draws the curve and sets the meters. The currents shown are the model’s: at rest it runs 0.8 mA, where the data sheet gives 0.86.
Some things are drawn: every output is shown the right way up (a valve stage turns the wave upside down); the dot on the curve and the electrons are slowed down; Symmetrical on the valve is drawn with the bottle’s second triode as a push-pull partner, which a valve power amplifier does with two bigger valves; the two stages are matched so the same Drive brings them to the edge together.