I'm rewiring a solid state amp. What is a good way to do the internal power wiring from the back of the amp to the on/off on the front and back again to the trafo?
My other amp uses just four wires. No extra insulation, not twisted (see picture) .
Four wires makes perfect sense and I would twist each pair together for aesthetic reasons. It will make no difference to the noise levels as the amp shown has no high gain parts near the cables.
I use double insulated wire here because it looks more beautifull and professional. If I have two wires w/o double insulation - I twist them and sometimes put into shining soft-silikone type termal-shrinkable insulation. It looks definitely better.