I‘m not an electrician, just an audiophile who’s had extensive listening experience with electrician installed dedicated lines using standard MCBs, standard Diazed and Neozed fuses, AHP optimized Klangmodul IIIs and more recently Gigawatt MCBs.How does this differ from a thermal magnetic breaker that might pass 250% overcurrent for 5 to 10 seconds. 100% overcurrent for a minute or so. 50% overcurrent for maybe 15 minutes. Etc. I am spouting off the cuff numbers, but there is a chart for every breaker out there. They don't just trip at their rated setting. A bolted fault on a 12 awg wire is something around 540 amps. The breaker will open within a cycle. A motor starting may be seen as 50 amps on a 20 A circuit for a second or so. Most breakers will allow this to happen hundreds, if not a thousand cycles. Eventually it may start tripping on startup.
Gigawatt is only rated for 16 amps. Every CB I know is rated for 20A for protection of a 12 AWG wire. You would think Gigawatt is throating down perfor.ance. So why is it a gigawatt "sounds" superior. Who knows. They very well may sound better. But I can not go there as a consultant. I work as best I can within the scope of NEC compliant so your homeowners insurance is fully intact if a power cord gets crushed and a fire starts.
In the UK, because electricians have access to the meter cabinet, where phase and neutral feeds can be split after the meter but before the consumer panel it is possible to install a second panel that is independent of the household panel, with its isolation switch and RCCB. The hi-fi panel can have its own optimised RCCB and MCBs, without the need to use buss bars, so changes in sound quality are pretty much down to the breakers and wire used. Sound quality improvement is per the above order.