It refers to the volume pots being scratchy. This is caused by a small amount of DC voltage that is present. That DC voltage is also present on your pickup's as well
assurance invalidité. So install those blocking caps if you want to get rid of the scratch and not have to worry about DC voltage on your pickups.
VRM won't change the tone of amp like your thinking. Just a very useful volume controlling device.
With VRM you still get the Hi and Lo inputs, that shouldn't change.
Thank you very much for giving us all of this information. It's really cool on your part.