how much for a fuse,

[booja30]

There is plenty of anecdotal reporting that ...

But there is plenty of anecdotal reporting of all kinds of things. You can find support for whatever you like (UFOs, vaccine conspiracies, 5G). It's the internet!

... I tend to a more prosaic idea: that these people are probably inveterate tweakers and, when messing about with mains fuses, detected or perceived a difference, improvement, in the sound quality. They then construct their own hypothesis about what this cause might be, and pursue a bit of ad-hoc development based on that hypothesis...

And then charge 10-1000x what it actually cost to make the item? The profit margin alone is enough reason for me to doubt their motives.

 

[Sue Pertwee-Tyr]

But there is plenty of anecdotal reporting of all kinds of things. You can find support for whatever you like (UFOs, vaccine conspiracies, 5G). It's the internet!

I mean you'll find it on pfm. That's where I've seen it.

And then charge 10-1000x what it actually cost to make the item? The profit margin alone is enough reason for me to doubt their motives.

What is an acceptable manufacturing profit margin, would you say? I agree that 1000x is excessive, but 10x is definitely pretty normal. I recall, decades ago, learning that the manufacturing cost of a Black and Decker electric drill was around £3, and the retail price then would have been around £40.

And then we have to decide whether your estimate of manufacturing costs is accurate. Let's say this is a cottage industry, and the 'foo' fuse starts life as a normal fuse which is modified in some way. Probably all hand-done, fiddly and time-consuming, and done in small batches. The labour cost alone could be considerable, and there's no efficiencies of scale in the manufacturing, so the raw material cost will probably be higher than for volume manufacture. And the packaging, and marketing costs, per unit, won't be negligible.

My wider point being that a fuse at £10-25 is probably not outrageously priced, if the complete cost of making, packaging, marketing and stocking is around £1-2 per fuse. I agree, £2000 for a fuse is silly, but that is the economics of Veblen goods, not manufacture, and that started with the fashion houses, not the audio industry.

 

[Barrymagrec]

The thing few people realise about foo fuses is that if you use one in a lighting circuit and it blows you get a truly inky blackness.

 

[John Phillips]

I'll assume the 'tiny, pathetic amplifier' bit wasn't intentionally ad-hom and aimed at me personally, so will move on.

There is plenty of anecdotal reporting that improvements at the substation have led to audible improvements to domestic hifi, so when substations were upgraded/enlarged, repaired, or just had key components replaced, eg those enormous capacitors, peolpe have reported that their hifi sounded better. They didn't know why, at the time, and only found out about the work on the substation subsequently. So I wouldn't rule out the idea that tightening up and cleaning every single contact, starting at the power plant, wouldn't or couldn't have a significant and audible effect. So If I were a betting man (I'm not) I'd probably take that bet, though there'd be no way to actually carry it through, of course.

But it's things like that which make me ponder over the mains impedance aspect....

I am not sure this will mean much to many, but FYI, United Kingdom in 1980 (see IEC TR 60725): 98% of customers had mains impedance arriving at the premises of better than 0.46 + j0.45 ohms; 90% had better than 0.25 + j0.23 ohms. Of the 230V 50 Hz countries UK is close to being top performer.

I don't know what is typical but IMHO designers probably should be designing kit to cope unobtrusively with the 90% level at least: 0.25 ohms resistance and 0.75 mH inductance (the j0.23 ohms). Of course no-one can guarantee all kit is well designed.

The resistance part of the impedance will impact the effective mains voltage you see. But the system should still guarantee you 216.2 volts to 253.0 volts as the big picture range. I did simulate a range of mains inductances and they did have a small impact on rectified power supply voltage levels, but the impact is tiny compared to the big picture range. Increased series inductance actually reduces and widens the big peak charging current a little from a linear power supply so could be thought of as beneficial by reducing harmonic content.

But there's still nothing there that gives me a clue about any possibility of a fuse making a difference.

 

[Sue Pertwee-Tyr]

John, thank you, and I take the point that the difference is tiny compared to the big picture range. But the big picture range doesn’t fluctuate from moment to moment, but more broadly hour to hour, so the small differences mooted above would occur against a notionally stable mains voltage, because they occur over a period of seconds or minutes apart.

 

[palacefan]

I have lived in two properties for an extensive time , one with an excellent power supply and one with a very poor supply. As per usual the same naysayers come along and we get the usual " it comes from the power station " end of argument stuff. Regenerators and methods of reducing RFI and removing other domestic items from hi-fi wiring systems can have enormous benefits. I have spent money with only one object and that is to improve sound quality.

The regular know all on here uses el cheapo interconnects and perhaps is blessed with a good power supply and his comments are based on that experience, try to run a good hi-fi system with poor power supplies with any exclusive what the book says system and I doubt that you will have a good system.

 

[John Phillips]

John, thank you, and I take the point that the difference is tiny compared to the big picture range. But the big picture range doesn’t fluctuate from moment to moment, but more broadly hour to hour, so the small differences mooted above would occur against a notionally stable mains voltage, because they occur over a period of seconds or minutes apart.

Sorry, I must have been unclear. There's nothing in my post above that happens faster than the big picture changes. The inductance which causes the tiny change I mentioned is to all intents and purposes constant. So the tiny change is an unvarying difference from operating kit in one premises compared to another.

 

[John Phillips]

I have lived in two properties for an extensive time , one with an excellent power supply and one with a very poor supply. As per usual the same naysayers come along and we get the usual " it comes from the power station " end of argument stuff. Regenerators and methods of reducing RFI and removing other domestic items from hi-fi wiring systems can have enormous benefits....

Very sorry indeed to pick on your post (and I am not asking you specifically for an answer) but I haven't experienced identifiable mains problems and my issue (in the context of this thread about fuses) is trying to understand how an audiophile fuse can deal with RFI. It may not be a question that many ask but it's definitely of interest to me and no-one yet can provide a good answer. (Sorry again.)

 

[Sue Pertwee-Tyr]

Sorry, I must have been unclear. There's nothing in my post above that happens faster than the big picture changes. The inductance which causes the tiny change I mentioned is to all intents and purposes constant. So the tiny change is an unvarying difference from operating kit in one premises compared to another.

No I don't think you were unclear, but perhaps I was.

What I took from your post was that any differences ascribed to changes/improvements to the impedance of the mains feed to the device, would be dwarfed by the normal, permissible, range of mains voltage. The inference being that, as well as being trivial, any changes would be masked by routine mains fluctuations. Hopefully I've summarised adequately for our purposes.

My point was, rather, that while the mains can fluctuate from ~216V to ~253V, it doesn't do this instantaneously; rather, those fluctuations happen over a longer time interval, probably measured in hours or perhaps days. So let's say you are doing an A/B test of mains leads (or fuses). You listen to A, make the changes, and listen to B. The time interval between hearing A and B is probably no more than a minute or two, and most likely shorter still. Over that interval, the mains voltage is hardly likely to have changed at all. So A vs B is done against a background of a notionally stable reference mains voltage. It matters less whether that voltage is 216 or 253V, than that it is the same for both.

And any changes/improvements to the sound via A or B are likely to be evident whether the mains voltage is 216 or 253V, though perhaps more evident the lower the mains voltage is.

 

[Darth Vader]

Hey John I see you are an engineer! In science we tend to use i but in branches of physics and in engineering that letter has been already taken to represent current. This means that I used to have to use both i and j depending to whom I was communicating. Something tells me that these mean sweet Fanny Adams to most on this thread........

Take this comment for example "It matters less whether that voltage is 216 or 253V, than that it is the same for both". This completely misses the point that a properly designed power supply will output exactly the same DC Voltage to the following electronics provided that its designed for this range. Of course for valve amps that derive the heater voltage directly from the mains via xformer step down its not healthy for them.

Cheers,

DV

 

[stevec67]

I have lived in two properties for an extensive time , one with an excellent power supply and one with a very poor supply. As per usual the same naysayers come along and we get the usual " it comes from the power station " end of argument stuff. Regenerators and methods of reducing RFI and removing other domestic items from hi-fi wiring systems can have enormous benefits. I have spent money with only one object and that is to improve sound quality.

The regular know all on here uses el cheapo interconnects and perhaps is blessed with a good power supply and his comments are based on that experience, try to run a good hi-fi system with poor power supplies with any exclusive what the book says system and I doubt that you will have a good system.

You're talking about regeneration, not an audiophile fuse. A regenerator does change the mains power, it has active components. A fuse doesn't.

 

[Ian G]

If you happen to live near anyone who operates large machinery ie. Industry you can watch the voltage raise and fall with the operation of equipment, three phase starting currents can be huge on pumps and fans, motors etc and will drag the voltage down to neighbouring properties. In a domestic environment using the electric shower will dim the lights due to voltage drop. Quite how much this effects sound quality is open to question. I very much doubt there is any measurable difference between the resistance of different domestic fuses and so the any discussion of impedance is a mute point when taken within the complete supply circuit. It would be useful to see the manufacturers specifications for their product along with an explanation of how it works. You'd be amazed how many connections require tightening when testing electrical installations, this goes from supply fuse right down to sockets and plugs. This would have far more effect than swapping a fuse even a £2000 fuse.

 

[Sue Pertwee-Tyr]

Take this comment for example "It matters less whether that voltage is 216 or 253V, than that it is the same for both". This completely misses the point that a properly designed power supply will output exactly the same DC Voltage to the following electronics provided that its designed for this range. Of course for valve amps that derive the heater voltage directly from the mains via xformer step down its not healthy for them.

I don't think it misses the point, rather the point wasn't pertinent to the argument; but, now that you raise it, I understand that the amount of ripple in the DC Voltage could/would vary depending on the input mains voltage, and the effects of this might well be audible downstream.

 

[CJ14]

I am not sure this will mean much to many, but FYI, United Kingdom in 1980 (see IEC TR 60725): 98% of customers had mains impedance arriving at the premises of better than 0.46 + j0.45 ohms; 90% had better than 0.25 + j0.23 ohms. Of the 230V 50 Hz countries UK is close to being top performer.

I don't know what is typical but IMHO designers probably should be designing kit to cope unobtrusively with the 90% level at least: 0.25 ohms resistance and 0.75 mH inductance (the j0.23 ohms). Of course no-one can guarantee all kit is well designed.

The resistance part of the impedance will impact the effective mains voltage you see. But the system should still guarantee you 216.2 volts to 253.0 volts as the big picture range. I did simulate a range of mains inductances and they did have a small impact on rectified power supply voltage levels, but the impact is tiny compared to the big picture range. Increased series inductance actually reduces and widens the big peak charging current a little from a linear power supply so could be thought of as beneficial by reducing harmonic content.

But there's still nothing there that gives me a clue about any possibility of a fuse making a difference.

My goodness it has been a long time since I saw J Notations, All wee need now is Radiums. Thank good memories.

Brian at O'Roukes worked is cost as 6 X Build including time, at Inca Tech we did 3 X Build incl time, but everything was made in the UK. Not in China at 5p/Hr.
TQ is 24 x cost plus time at £25/hr plus pixie dust

 

[Mike Reed]

The case evidence is in the ear of the confused holder. (Confuse us).

 

[chartz]

The case evidence is in the ear of the confused holder. (Confuse us).

 

[mansr]

I don't think it misses the point, rather the point wasn't pertinent to the argument; but, now that you raise it, I understand that the amount of ripple in the DC Voltage could/would vary depending on the input mains voltage, and the effects of this might well be audible downstream.

Still nothing to do with fuses.

 

[herb]

Some equipment is more sensitive to fuse characteristics?

10 years ago I could not get my normal Bussmann 13 amp fuses so I bought some Marbo 13 amp fuses. Equipment was Naim/Farlowe Exposures, fuses were cleaned chemically by me. Immediately the sound changed and in this system not for the better, all fuses were of course dead cheap. I found some Bussmanns and the sound reverted to normal.

I suspect that my replacement ATC integrated amp is better designed (not too sure about that) with different topography. I have not repeated the 'experiment'.

 

[stevec67]

Some equipment is more sensitive to fuse characteristics?

10 years ago I could not get my normal Bussmann 13 amp fuses so I bought some Marbo 13 amp fuses. Equipment was Naim/Farlowe Exposures, fuses were cleaned chemically by me. Immediately the sound changed and in this system not for the better, all fuses were of course dead cheap. I found some Bussmanns and the sound reverted to normal.

I suspect that my replacement ATC integrated amp is better designed (not too sure about that) with different topography. I have not repeated the 'experiment'.

You should repeat the experiment. I suspect you imagined the difference. A fuse doesn't do anything to the incoming supply, this is then transformed to a lower voltage, rectified to DC, smoothed, regulated, and drives the power rails. The physics of all of this is known the the nth degree, to ascribe an audible change to a fuse change is rewriting the laws of physics from Page 1.

 

[Ian G]

Were you replacing like for like ? Confusing 240v fuses and small DC fuses may well have an effect on current flow. The fuses being discussed rely on heating of the fuse wire to the point of failure.