On the main PCB remove R25, R17, and R27

Solder one lead of the 2.2M resistor to the hole on the left side of R25 and couple the other lead to the right side of R57

Also couple one lead of the 56K resistor to the right side of R57 as well with the other lead of the 56k resistor going to the bottom hole of R17

Solder the 1M resistor to the left side of R25 and the bottom of R26. I like to leave it a little long so there's space between this resistor and R57

Jumper R27 with a lead from a clipped component

Remove the lead going from 7(V-4) to V4 pin 7. Install 470k resistor from 7(V-4) to pin 7. Desolder the blue lead from pin 6 of V4. Wrap the blue lead around the 470k resistor and re-solder to pin 6. Make sure the 470k resistor isn't touching the standoff screw or any other tube pins!

This mod moves the phase inverter's power supply to an unused higher voltage power supply increasing clarity, clean headroom, and tone! It also grid biases the phase inverter to prevent the harsh doubling distortion it has stock when it starts to break up. We also add a grid resistor to further smooth out the phase inverter as it's driven.

The difference between this and earlier versions is that we change where the phase inverter grid resistor is grounding because we change the grounding scheme in this version of the kit in later steps.