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Old 1st Jul 2019, 4:43 pm   #37
Lucien Nunes
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Join Date: Apr 2008
Location: London, UK.
Posts: 1,756
Default Re: 13 amp fuse for 1.5mm mains flex?

The reason being (I found out later) is to reduce the impedance of the cable
The idea circulates in the HiFi world that this is significant, but it isn't. A typical mains transformer in a large domestic power amplfiier has a primary resistance of a few ohms, possibly 10-20 ohms in a smaller one. Yet the resistance of a 5A fuse is a tiny 12 milliohms cold and a 13A fuse perhaps three milliohms. Saving nine milliohms in a circuit with a total resistance of many ohms is trivial.

If one insists on disregarding the load resistance and considering only the supply impedance, in a domestic situation that is likely to be in the order of half an ohm, so the fuse still only accounts for a few percent. Moving the equipment plug from one socket to another just one metre further from the fuse box would have a greater effect on the sound. Clearly, no commercial equipment could be made that intolerant of external conditions.

Or could it... further discussion invited in the audiophool thread!
Three anodes good, six anodes better!
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