CTC5 special, low 145V source

[Electronic M]

I may be stating the obvious but in most sets where a B+ rail originates from the audio output cathode, the audio output tube is being used as a B+ dropping resistor... Thus it's quiescent DC current biasing voltages are critical to correct B+. Check all the bias resistors and lift any grid capacitors, and sub the 145V rail filter cap... May also want to unhook the 145V rail from the audio output tube and measure the current it draws from the supply and compare it to the bias current the audio output tube should pass with how it's biased (looking at the schematic voltages and looking them up on the curve in the tubes datasheet should give you design current).

Haven't had this problem with my CTC-5s, but that's how I would approach it if I did.