Hi there,about the power bulb,don't worry about it in this amp.I believe what you are refering to is what used to be done in cheap amps without a power transformer.They series all the heaters on all the tubes to add up to around 117 volts,this may or may not include the pilot light,so if the bulb was missing the amp wouldn't come on.The down side to this is that if the amp won't come on,you have to check all the tubes and the light to see which one is bad.This was real popular in those 5 - 6 tube "table top" radios of the 50's and 60's. As long as you have a power trans.,you're ok.Just replace the bulb,but the amp will work fine without it.Good luck,Mel. P.S. You're lucky,I'd kill to have an old one like that !