Hi Koi -- The two resistors circled on the schematic that are labeled " To Output of LM337" are not part of this discussion. Those resistors exist to raise (or "bias") the heater voltage above ground by a small DC value, and in a balanced fashion, so as to help minimize any noise that might be generated in the input stage tubes if the bias were not otherwise used.
The focus of my comment about the missing filter section centers on the missing 330Ω resistor (shown after the choke on the power supply page), and final filter cap that are not installed in your build. Note that on the schematic after the choke, power is applied to the OPT center tap connections (being the 375 volt supply point), and also the next filter section -- the missing 330Ω resistor -- that then supplies the 370 volt output tube screen grid supply point (pin 9 of the tubes), and also the next filter section after that (the 10K resistor) as well. In your build however, there is no 330Ω resistor. The point after the choke feeds both the OPT center tap leads AND the feed to the output tube screen grids, as well as the 10K resistor supplying the driver tube supply point. In other words, the screen grid supply point as shown on the schematic is completely missing in your build.
To correct this, you need to replace the 10K resistor with a 330Ω resistor, and move the screen grid supply lead from its current position after the choke, to the cap after the 330Ω resistor. From that point (after the 330Ω resistor), you also need to then reconnect the 10K resistor, and have it tie to a new isolated terminal, where a new (additional) single power supply cap is connected between there and ground (the 30 uF cap at the new 340 volt supply point shown on the schematic), and from which power is then supplied to the driver tubes.
I hope this helps!
Dave
Edit -- Looks like Gadget covered this for you as well.