Hi,
I did an ST-70 rebuild a few years ago, but haven't used it much due to a heat problem. After a few hours on (used or just idling), the Triode Electronics PA060S power transformer gets to 136℉.
Just did a little checking and I actually had the outputs running a bit cold at 18mA per tube rather than 50mA. I did just increase idle to 23mA per tube and I'll leave it at that for now.
Although I'm using ECC99s in place of the 12AU7s, I'm still within the filament specs at just under 4A per winding. B+ is 355V, but I do question the first stage of the PSU. Is this how the waveform is supposed to look on the first cap section before the inductor? scale is 100V/div