Proper routing of wiring on a chassis is called "Lead Dress", and depending on the situation, can be critical to performance.
Maybe I got lucky, as I'd never heard of this before. Rearranging the wiring just seemed sensible. But there is no audible hum/buzz/hiss at any volume when the amp is on and any of my 3 input sources are selected without playing audio (streamer paused/turntable running but stylus not on vinyl/CD player on but paused).
I'd still like to use headphones occasionally tho 😊
I'd still like to use headphones occasionally tho 😊