What a lovely video of his ceiling!
I have seen a few threads on Roger’s system on other forums and decided to have a read. I did find his chassis grounding tweaks interesting as couple of photos of it really stood out to me.
More on those after a little anecdote (it has some relevance but as it happened a few years ago I don't have the measurements and test readings to back it up!)
A long time ago in a galaxy far, far away….
….whilst carrying out an inspection of an electrical control panel, it was noted that one of the incoming phase conductors inside the panel was showing severe signs of overheating. This conductor had damage and discolouration to the insulation that were an obvious sign of excessive heat. Inspecting the incoming phase conductors with a thermal imaging camera showed a dramatic temperature difference between them but was localised to where it terminated into the MCCB (Moulded Case Circuit Breaker).
To terminate the cable to the MCCB, a lug with a hole in it, is crimped to the conductor and then bolted to the large flat stubs of the MCCB giving a nice tight connection with a large contact area. Now to cause such localised heat there had to be something wrong with this termination. So I checked the tightness of the bolt, that was fine. I inspected the crimp termination, that was fine and had been done using a crimping tool with a hexagonal die (rather than an indent crimping tool). It wasn't until disconnecting the conductor that I could see the problem.
This control panel is switched off at the MCCB every night, so to combat the problem of condensation there are couple of small heaters inside the panel. These are connected to the supply side of the MCCB using a conductor of a much smaller gauge and therefore the crimp lug, while retaining the correct size hole to be bolted to the MCCB, is a fraction of the size. This was sandwiched between the crimped lug of the main conductor and the stub significantly reducing the contact area and increasing the resistance of the termination. Well I'm sure you can guess what happens when you have almost 200 Amps passing through it.
So back to the photos of Rogers system,
View attachment 8552 View attachment 8553
We have large gauge cables with low resistance but connected with tiny screws, making a minimal contact to the cables crimped lugs, against a painted metal cover which probably provides little to no contact area. I'm happy to be corrected on this, but it just seems to go against all logic.
If there ever was a clearer audiophile example of a "bottleneck" I'd like to see it!