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Anyone can read circuit diagram? Want to change fuse

Academic point -

UK law is economical when it comes to how the use of approved anything is used/supplied etc.. In this case, if something went wrong, the installer would be negligent under various laws, fitting something to an incorrect standard in itself is generally not illegal.
The first time that I was made aware of this was by a local Trading Standards Officer - it is not illegal to use a tractor without a safety cab in the UK, but if something goes wrong, you are in deep do-do if no safety cab or roll bar was fitted. That way, no law aimed at protecting a consumer is ever out of date - the law just follows the regulations/standards.
 
Barrymagrec said:
Fuses have no direction - but do they all need to be changed?
Click to expand...

When I went on a search for the correct equipment fuse for my XPS (the one that sits in a carrier by the IEC socket) so that I had a spare in the house, I found this on the Naim forum under a title ‘Fuse Orientation’, the point of the advice being that one orientation sounded different/better than the other:

“If the kite safety mark is embossed on the edge of the of the fuse’s conductive cap the fuse value should point towards the bottom of the fuse holder. Should the kite mark be embossed on the very end of the fuse’s cap then the fuse value should face the top of the fuse holder.”

I confess I didn’t bother to check the orientation of the installed fuse.
 
I'm surprised that, with all the hifi and electronics experts on this forum, that no one has mentioned the obvious solution!

As Pete MB&D said,
Pete MB&D said:
Looks like it's on the AC input from the transformer so you will have to swap them round 50 times a second.
Click to expand...

This is a facetious suggestion as, since you appear to have many such fuses in your equipment, it is clearly impossible to switch ALL of the fuses around 50 times a second, ALL at the exact time that the ac polarity changes!

The solution, since the manufacturers confirm that these fuses are directional, is to use them in parallel pairs, connected in opposite polarities (or in technical terms, with the writing going left to right on one and right to left on the other).

This would ensure that, at any moment, one of the fuses would be conducting in the "right" direction.

It has the added benefit that, having spent twice as much on your "magic fuses" you would clearly hear twice the improvement in sound quality.

"Simples"!
 
If we are going to be pedantic - get the change frequency correct - polarity changes twice every cycle, so the fuse would need to be changed 100 times per second - 100Hz. The same applies hum, flicker etc. on mains - the frequency of the mains is a nominal 50Hz, but most effects are 100 Hz as a consequence.
 
Vinny said:
If we are going to be pedantic - get the change frequency correct - polarity changes twice every cycle, so the fuse would need to be changed 100 times per second - 100Hz. The same applies hum, flicker etc. on mains - the frequency of the mains is a nominal 50Hz, but most effects are 100 Hz as a consequence.
Click to expand...

Of course! Silly me, it must be late!
 
Its a very poorly designed circuit that needs that many fuses ???
FFS just solder a piece of copper wire in all of them, oh and it doesent matter which way round the copper wire goes, it will still sound better than any foose
Alan
 
Yes but those are plug fuses, not 5x20mm ones.....

I do like the way he states that they have “Nickel plated end caps”, erm, yes, that’s what the end caps of any 20p fuse are.....
 
I'm intrigued by the maker's claim that the fuses they sell have been 'tested'. :) Usually, when I've done that I throw them in the bin. If it makes them *this* valuable I guess I should have been stockpiling them. Should I also do with with matches?...

My advice to the OP is simple. If you find that putting them in the wrong way around spoils the sound, then you can use that to find out for yourself which way round they should be. If you can't tell, return them and get yer money back.

I didn't even know electrons could read! :)
 
peterm said:
I'm surprised that, with all the hifi and electronics experts on this forum, that no one has mentioned the obvious solution!


The solution, since the manufacturers confirm that these fuses are directional, is to use them in parallel pairs, connected in opposite polarities (or in technical terms, with the writing going left to right on one and right to left on the other).
Click to expand...

Slightly worried someone may take that seriously. I'm not sure how well fuses would 'current share' in an overload situation, so correctly chosing the values for two in parallel in place of one is uncertain from my POV.

My own view is that if your HiFi's sound depends on which way round the fuses are, then your *HiFi* may need checking or changing, not just the fuses!
 
YNWOAN said:
Yes but those are plug fuses, not 5x20mm ones.....

I do like the way he states that they have “Nickel plated end caps”, erm, yes, that’s what the end caps of any 20p fuse are.....
Click to expand...
And aluminium silicate is probably kaolin powder, which may not be a good idea, from https://www.fuseco.com.au/fuses/faqs:
"Current limiting fuses contain a granular filler, usually high purity quartz sand of a defined grain size and packaging density. The specific grain size distribution provides room to expand for the vapours and gases produced by the arc and offers a large surface for efficient cooling. The filler does melt under the influence of high arc temperatures, absorbing an enormous amount of energy and extinguishing the arc well before current zero. Fused quartz and metal form a non-conductive fulgurite body that prevents re-striking of the arc."
 
mjw said:
When I went on a search for the correct equipment fuse for my XPS (the one that sits in a carrier by the IEC socket) so that I had a spare in the house, I found this on the Naim forum under a title ‘Fuse Orientation’, the point of the advice being that one orientation sounded different/better than the other:

“If the kite safety mark is embossed on the edge of the of the fuse’s conductive cap the fuse value should point towards the bottom of the fuse holder. Should the kite mark be embossed on the very end of the fuse’s cap then the fuse value should face the top of the fuse holder.”

I confess I didn’t bother to check the orientation of the installed fuse.
Click to expand...
Is that advice from a forum member or from Naim?
 
troll.jpg
 
It must be the amount of snake oil and fairy dust the fuses have inside them this would explain the cost as
snakes are hard to milk :eek:
 
Honestly, expensive fuses now?

And no, wires are not directional, never were, never will be, sorry.

You might want to replace that hair-thin wire in the transformer too, as well as the microscopic leads to the transistor chips.
 
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