814 in triode

i had to make the 814 triode curves myself to be able to use them that way.

so i took all i could from the penthode curves and guesstimated the rest and made some idealised triode curves:

i curve‐fitted µ to 8½, rp is around 2k for healthy currents. the zero volt grid line is marked, and then the regularly spaced grid lines are all 10 volts up/down. the steep line near the y‑axis is the rectification line (grid volts = plate volts): you want to stay away from there.

the diagonal line and the three extra gridlines are the class‑a2 set‑up i chose from this info. 475 volt on the plate, 80ma, -25½ volt on the grid. 5k opt load. 67½ volt of grid swing needed to deliver about 15 watts.

the result has the dht tungsten sound that i love, and you can hear the power headroom: big sound.