Bit of a fabrication, Ian. Mine was installed by a qualified electrician a little over 10 years ago (not 20). Why you think my installation is potentially dangerous was never explained by previous posters, nor you. Regulations change and that's the electrician's job to advise, as I said, though doubt that T & E cable, consumer units (now changed back to metal), RCBOs etc, have changed much (if at all).
Your patronising stance is totally out of context and order, as I fully maintain that it's best to have a good idea of one's mains NEEDS apropos one's system and placement as well as room/dwelling logistics BEFORE asking a sparks to come in to advise on the electrical side. One aspect of this is cable routing. Surely better to have an idea of how cable(s) can be easily routed from incoming to your chosen hifi position. This ongoing contretemps is tiring and unnecessary as you seem to conflate 'electrician' with 'hifi needs' expert or are simply misrepresenting my posts.
An example for you: a friend has had a multi-cable system not dissimilar to mine but for longer than me; his friend, a keen audiophile electrician owning a company employing others, installed his own radial system based upon advice and inspection of my friend's system. He probably adapted it but the idea and motivation directly emanated from my friend. Of course the installations were kosher as well; hardly DIY !