[radiomikee]

When the tube starts to glow red and get really hot, it means it is drawing alot more current than normal. This can happen in audio output tubes when the incorrect bias voltage is applied to the screen grid. Check the power supply voltage dividing/biasing resistor for continuity between all sections, and ground, you may need to take the wires off the terminals to be sure. One dead section in the primary of an output transformer will not cause the tube to glow red. Check all the electrolytic condensers for correct polarity of connections, particularly the one that runs from the power transformer high voltage center tap to the chassis, needs to be negative on the center tap, positive on the chassis.