This step will change the grounding to be more like a vintage amp and lower the noise floor of your amp.

Remove R60( and the solder from the hole on the left side) and install a solder lug in the standoff screw next to R60. Using a lead clipped from the filter caps solder one end to the solder lug and the other to the left hole of R60 - see photo. It's easier to attach the lug to the screw before soldering the R60 hole.

Remove Jumpers W3 & W9( and the solder from the left side of W3). Install a solder lug in the standoff screw next to the control pcb header. Using a lead clipped from the filter caps solder one end to the solder lug and the other to the left side of W3 - see photo

If you have an earlier version of the kit you're welcome to do this( and I recommend it), but your kit won't have the solder lugs or resistor.