My hi-fi audio line took shape after years and years of servicing musical instrument amplifiers and using these devices endlessly. To me it is simply second nature to plug into the front of an amp and reach around to the back to flip up a switch to turn it on. It’s just natural.
My speaker outputs are on the back as is my fuse holder. This allows for a straight flow of the signal path from front to back. Laying out the parts was almost automatic with two channels flanking a central ground bus. The amp is dead quiet. You can see images of finished stereo tube amp here.