Thorn -- The schematic I posted is in post #13, and shows three partial circuits: At the top is the original design of the phase inverter stage showing the noose resistor. The bottom left is the modification that (ideally) would be used in the right channel, and could also certainly be used in the left channel as well, but the modification is further broken down at the bottom right to show how a slight variation on the modification allows it to also provide heater bias as well. So the installation I have shown shows the version on the bottom left of the schematic installed in the right channel (left side of pic), while the version at the bottom right of the schematic is installed in the left channel (right side of pic). With regards to correcting the bias for the driver tubes, either version of the modification performs that job identically, but the version on the bottom right of the schematic also provides heater bias as well. Using that version is optional, but recommended, and only needs to be used in one (either) channel -- I simply chose to use it in the left channel shown at the right side of the underside pic. The simpler version shown at the bottom left of the schematic is then used in whichever channel the other version is not used in. Installation is not particularly difficult at all. Assuming you will install the simplest version in both channels, you will need: two 47K@0.5W, two 91K@0.5W, and two 22uF@160 vdc electrolytic caps. Based on starting with a perfectly stock receiver then, the procedure in each channel is as follows:
1. Locate pin 3 of the driver tube to find a coupling cap, 68K, and 150K resistor (which you've already removed) located there. Remove the 68K and 150K resistors (the latter of which you've already done).
2. If you installed the unvetted noose removal procedure earlier, then the 470K resistor connected to pin 2 of each driver tube had previously had its other end disconnected from the center terminal of the phase inverter control, and connected to a lower voltage source. That work needs to be removed, so that the 470K resistors are reconnected to the center terminal of their respective phase inverter controls again as before. Any wiring previously installed to apply the alternate power to these resistors then needs to be removed.
3. Determine how you wish to secure the 22 uF 160vdc cap, either with adhesive, or more professionally using the T-strip shown as I did. The negative lead of these caps is grounded to a convenient ground point, while their positive lead will connect to a new connection point (created by the T-strip) that is insulated from the chassis.
4. From the new insulated connection point, besides the positive lead of the 22 uF cap, also connect a 91K resistor to ground. Also, from the new insulated connection point, connect a 47K resistor, with the other end connected to pin 3 of the driver tube. There are now three leads connected to the new insulated connection point.
And that's it. If you install the version in one channel that provides heater bias, you will need to provide two new insulated connection points in the channel it is installed in. That's why you see a 2 terminal T-Strip in one channel of my installation, and a 3 terminal T-Strip in the other. On each of these T-strips, one terminal ground, while the others are insulated from ground to allow the connections made to them to work properly.
I hope this helps!
Dave