my question is, how you gonna do that, if all 3 are in the same jacket, as in 10/2 Romex?
Whitlock is talking about single conductors pulled in a conduct or installed is a raceway. As I said in an earlier post twisting the hot and neutral wires together before installing them in a conduit may not meet code. Are you planning on installing conduit?
Whitlock showed the second best choice being 2 wire with ground MC armor cable followed by Romex. You can slightly twist Romex, but to much, to tight, will change the geometry of the lay of the equipment grounding conductor in relation, between, the hot and neutral conductors. Just a slight spiral twist in the entire length of the cable. Slight.....
FWIW I have to runs of 10-2 with ground NM-B, Romex, that are about 75ft each and my 2 channel system is dead quiet. Preamp and amp are tubes.
It is important to keep the individual dedicated branch circuits separated from one another as soon as possible, within reason, after they leave the electrical panel. You do not want them running parallel next to one another.