I see some preamp, amp, passive preamp wiring designs, that use the steel enclosure as negative (not ground). Where all jacks are mounted uninsulated and wired positive but only one jack is negatively wired to the chassis. All other jacks use the chassis as negative. Is this considered good practice? I'm far from knowledgeable in this area, but is using the entire chassis in place of a matching positive wire, considered good practice?