Magic Fuses ????

Khan posted:

So I was under the impression that the fuses should not be changed on Naim gear. Also how much difference can I expect, compared to a power cable or a good distribution block?

Obviously the safety fuses in the actual equipment should not be fiddled with - if one of these fuses blows then you must replace with the exact same type and rating (your Naim dealer can supply).  If the fuse continues to blow then it could indicate a fault.  Do not under any circumstance be tempted to "uprate" the internal safety fuse.  Any attempt to do so could render the equipment unsafe, will invalidate any warranty, and may well jeopardise your home and family should a serious fire arise as a consequence.

james n posted:

Khan posted:

So I was under the impression that the fuses should not be changed on Naim gear. Also how much difference can I expect, compared to a power cable or a good distribution block?

Internal equipment fuses are a no-no but fuses in the plugs are ok (check ratings etc)

I'd not bother myself but if you're so inclined...

As far as I know the fuses are sale or return, so you can try before you buy...

personally I am extremely impressed, surprisingly good

Ah I see. Yes I was speculating from memory. That’s what I had read before. So changing fuses in a plug with the same rating. Can this really make a difference? I thought fuses all serve a purpose of safety to trip in case of an overload. Am I completely mistaken?

The fuse you find in a UK spec mains plug is there to protect the flex from any over-current - UK circuits can sometimes be rated at much higher amperage than elsewhere, hence why a plug fuse (and adaptor fuse) is required.

The fuse inside the equipment is there to prevent serious damage from a fault, and to stop it turning into an instant fireball should there be a catastrophic failure such as a breakdown inside the transformer.

Khan posted:

Ah I see. Yes I was speculating from memory. That’s what I had read before. So changing fuses in a plug with the same rating. Can this really make a difference? I thought fuses all serve a purpose of safety to trip in case of an overload. Am I completely mistaken?

No you are completely correct. A short circuit would allow too much current to flow and therefore potentially overheat parts of the circuit, possibly causing a fire. A fuse is essentially a piece of wire that is designed to melt and break the circuit in the event that more than the desired current flows. 

Why do SR Blue fuses improve the sound? They don’t!  Its just that something about their construction does less damage than a regular fuse. What that something is I’ve no idea but fuses are passive, so can’t add anything but can of course subtract. The SR Blue fuse subtracts less than a regular fuse, hence the apparent improvement. 

It would certainly be useful to be able to measure the differences because measuring infers that we understand what the difference is and from there, what causes it. The fact that we can’t or don’t know what to measure doesn’t mean that there isn’t a difference but it does generally mean that we don’t yet understand why there’s a difference....Off course its not good marketing to say that something makes a difference but we haven’t a clue why, so manufacturers generally either speculate or try to make up a plausible theory, which gets the product a reputation as ‘snake oil’, although the difference may be absolutely genuine and the absolute antithesis of oily snake.

If we can persuade people with XPS's to install these fuses I may buy shares in the company that makes these.

Snake Oil or not, it's important that these devices do what they are supposed to do and 'melt' in an over-current situation, as rated and that that melting is contained with no flames. A fuse isn't just a piece of wire, but also non-combustable material to absorb any fire contained within a capsule, which also shouldn't shater or otherwise destruct in the over-current sitiation.

To this end I would be avoiding anything not BS* tested (or at least marked), whatever benefit it may produce - it has to perform it's primary function and the owner has to be prepared to write off the cost of the fuse if it does pop.

*BS - British Standard, not what you may be thinking based on what we're discussing