WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Am I right to conclude that if the output capacitor say in an SRPP circuit fails on short, I would end up with all the high anode DC voltage on the output port with the consequence of blowing up anything which is connected with this output ?
Yes, you are right. If this worries you you could add protection diodes (e.g. a pair of zeners), but there is a risk of some distortion. You could use mains-rated caps (X or Y), as these are guaranteed not to fail short circuit.
