Fuses do affect sound, the question is how much

[zepplock]

Like interjecting posts about cable directionality into a thread about fuses? Look, we've all said it does not matter at audio, and @audio2design was basically correcting my flat statement about non-directionality of cables with a proper qualification, which then got questioned, and here we are.

None of this last bit is about audio, or fuses, or directional audiophile cables or fuses. It was a tangent to clarify an absolute that was not true that devolved into a pissing contest.

you are right, apologies to @audio2design for derailing it and misreading his comments.

 

[tomelex]

I thought that OFC has a tiny bit higher conductivity. It also has a tiny bit more corrosion resistance, so it is less likely, over the millennia, to build up a non-conductive patina. It's also more resistant to hot hydrogen causing structural weaknesses. For example, CuOFP (oxygen-free copper with phosphorus) is used to pack spent nuclear fuel rods.

Here's something fun. Belden 5100UP, bare copper speaker wire, 2 conductor 14 AWG is 2.42 ohm/1000ft and 29 pF/ft, rated at 22A. Their CuOF high-conductivity speaker cable 1309A, 2 conductor 14 AWG is 2.5 ohm/1000ft and 20.5 pF/ft, rated at 13A. Over 20ft, would that extra 170 pF make a difference? I doubt it. That's like < 5% of a small crossover cap, and in parallel so it simply adds.

Marc

Yes, OFC is better by a little bit. Please look at attached, however, I do not know the real specifics of their measurement system, and these super small variances in resistance could be just temp drift or any number of things, but their point is their fuse is a bit better, and there is an ohmic directivity according to them, again all very small and not enough info to determine the real science of the experiment, but as i said, when you start getting way down in the super small world, you will always find some kind of variances, but audibility of these super small things, no. However, depending on the signal you put through a fuse ( ie pulses and repitition rates, you can see the results of the non linearity due to the heating of the fuse elements, this was known , oh gosh, 40 years ago atleast by me, I read about it in an AES Journal back then. David Hafler compensated for this in his DH220 amps for sure, as I have those still to this day out in the garage.

Also, one would have to do these experiments several times to show if there were these effects just from lack of proper contact and all kinds of other things, so when you look at the results its hard to fully be on board, maybe they did repeats and maybe not, who knows.



http://www.ultrasystem.com/documents/WorldsLargestFsMsrmtReport.pdf

 

[tomelex]

Yep guys, lets keep this thread on fuses only as best we can, thanks to all for helping keep us on track.

 

[MediumRare]

I like to collect a list of such topics to put to test one day. Would be interesting to measure what the fuse does when current pulsates through it. Thomas, will you send me some of your expensive fuses to test with?

Any thought to doing this debunking experiment?

 

[radix]

However, depending on the signal you put through a fuse ( ie pulses and repitition rates, you can see the results of the non linearity due to the heating of the fuse elements, this was known , oh gosh, 40 years ago atleast by me, I read about it in an AES Journal back then. David Hafler compensated for this in his DH220 amps for sure, as I have those still to this day out in the garage.

http://www.ultrasystem.com/documents/WorldsLargestFsMsrmtReport.pdf

So they are measuring mains fuses, right, not speaker protection fuses? The differences seem to be in the < 0.1 mOhm range. In their 3A DC tests, that corresponds to < 0.3 mV differences. What was the ripple on their power supply? There's no methodology section in that report, so who knows how they measured, what they measured with, or any statistics related to the measurements. If you're measuring differences in the uV range, you need to be pretty careful. What did they do to ensure temperature stability of their resistive load? Did they thermally equalize the fuses? Over what period of time did they measure -- even very good DMM will have a calibration range that varies with temperature and time that will be in the uV range.

I'm just not seeing how such small differences on mains voltages could carry through to measurable much less audible differences in the audio signal after a switching power supply followed by a filtering stage, combined with the PSRR of the amplifier design.

Anyway, do I believe they measured something different in each direction? yes. Do I think it has any statistical significance based on that report? No, not without a detailed methodology section. And even if their measurements are significant, do I think those tiny differences in mains voltage and current make a difference to the analog amp stage? no.

Maybe I need to buy some fuses and measure some micro-volts.

Marc

 

[3dbinCanada]

So they are measuring mains fuses, right, not speaker protection fuses? The differences seem to be in the < 0.1 mOhm range. In their 3A DC tests, that corresponds to < 0.3 mV differences. What was the ripple on their power supply? There's no methodology section in that report, so who knows how they measured, what they measured with, or any statistics related to the measurements. If you're measuring differences in the uV range, you need to be pretty careful. What did they do to ensure temperature stability of their resistive load? Did they thermally equalize the fuses? Over what period of time did they measure -- even very good DMM will have a calibration range that varies with temperature and time that will be in the uV range.

I'm just not seeing how such small differences on mains voltages could carry through to measurable much less audible differences in the audio signal after a switching power supply followed by a filtering stage, combined with the PSRR of the amplifier design.

Anyway, do I believe they measured something different in each direction? yes. Do I think it has any statistical significance based on that report? No, not without a detailed methodology section. And even if their measurements are significant, do I think those tiny differences in mains voltage and current make a difference to the analog amp stage? no.

Maybe I need to buy some fuses and measure some micro-volts.

Marc

Marc, even if they managed to accurately measure a couple of microvolts in difference, it would remain inaudible using pink noise, a spectral dense signal. A spectral dense signal is required to be able to detect the noise anomaly. Fuses do not impart a sound into the audio chain.

 

[Cbdb2]

Considering the mains voltage drifts constantly, sometimes changing as much as 5 volts what kind of moron thinks a few millivolts of mains voltage drop across a fuse will make a difference.

 

[tomelex]

So they are measuring mains fuses, right, not speaker protection fuses? The differences seem to be in the < 0.1 mOhm range. In their 3A DC tests, that corresponds to < 0.3 mV differences. What was the ripple on their power supply? There's no methodology section in that report, so who knows how they measured, what they measured with, or any statistics related to the measurements. If you're measuring differences in the uV range, you need to be pretty careful. What did they do to ensure temperature stability of their resistive load? Did they thermally equalize the fuses? Over what period of time did they measure -- even very good DMM will have a calibration range that varies with temperature and time that will be in the uV range.

I'm just not seeing how such small differences on mains voltages could carry through to measurable much less audible differences in the audio signal after a switching power supply followed by a filtering stage, combined with the PSRR of the amplifier design.

Anyway, do I believe they measured something different in each direction? yes. Do I think it has any statistical significance based on that report? No, not without a detailed methodology section. And even if their measurements are significant, do I think those tiny differences in mains voltage and current make a difference to the analog amp stage? no.

Maybe I need to buy some fuses and measure some micro-volts.

Marc

Yes, no real clear evidence of their "scientific experiment" ahahhah. They showed directivity in resistance, and it is insignificant, but it is there, and that is where a lot of snake oil folks step up to the plate and claim its audible. They show their cryo stuff is a bit better, and there again they have a selling point to the audio masses that do not have much scientific background.

Are there systems out there and fuse types that you can put in and cause some sort of measureable difference to the output signal, I would say yes, you can always create the perfect storm if you want, but we all know blind tests reveal audible differences, and these folks will never take a blind test, however, I would always confirm with measurements that they do not have the perfect sh?t storm of weird audio setup before I would put my money down. There is a lot of weird equipment in the audio world. As I mentioned in the first post, fuses do change with signal level, if they did not they would not work! That does not, of course, mean you can hear it easily, if at all in normal designed gear.

People really are faith based in a lot of ways, and blind tests are a pill they will never swallow. Fuses are electro-mechanical devices, they can act strange, they can make and break contact in the ferrules and they can sometimes just be plain wrongly marked, the sand filled ceramics types can act different than the regular wire in an empty tube type.

Years ago I had an extra hour of troubleshooting and scratching my head dealing with an intermittent fuse, ohmed out OK but then became a high resistance once back in the circuit. I was young and inexperienced then and could doubt myself when it came to electronics and come up with all kinds of theories of what was going on in the circuit, where nowadays I would know there was no "magic", measurements done correctly do not lie.

 

[tomelex]

Fuses besides being sort of electro-mechanical, basically age every time you turn something on, they get older, like the filament of a tube. This wear and tear affects them physically, for example, the tin plating on an old fuse wire can migrate into the wire a bit, so the actual fuse element is weaker.

And, if the fuse is running near its current interrupt point, it can have a measurable affect on distortion with the right input signal. Also, you may have noticed that fuses sometimes blow at turn on after you have been running something for a long time,

ie you turn it off then turn back on and the fuse blows, this is from wear and aging of the fuse, or from the fact that a fuse is set up to work correctly when cold vs when near its interrupt rating at turn on, ie if you have been pounding out the tunes all day at a high stress level for the fuse, then switch the amp off then back on, well, the fuse is not cold, its hot, and the I squared T thermal function will already be nearly ready to blow because of the existing heat. So, these things are not just a simple thing. A blown fuse, first time blow, is not always a circuit problem, but could be just a tired old fellow who has seen better days, so sad, reminds me of me ahahahahha

 

[audio2design]

Why are you changing subject? Who cares about high frequencies. This is audio forum. No one can hear 10Ghz.
Just admit you spit out some BS without reading the context and be done with it.

NO, I absolutely knew the context. Perhaps you did not and did not follow back to my original post. There is a big difference between "no directional component" and "the directional component is many orders of magnitude below audibility" from an engineering and truth standpoint. One statement stands up to scrutiny, the other does not.

 

[audio2design]

The funny thing about fuses is, with almost no exceptions, the higher the resistance, the lower the noise of the power supply, if you can measure a difference at all. Adding resistance to the AC supply line does not degrade performance with exception of a smidgeon of top end, and/or a bad design that biases something off the raw rail voltage. Add resistance to the AC line and it will filter out high frequencies on the AC line and make the DC power cleaner. Even under heavy current draw it will still be cleaner.

So, when a fuse company claims their super duper audio fuse lowers resistance and hence is better, you know it is BS. Of course, I do get the impression Synergistic fuses are actually higher resistance, likely lower rated current than they claim, hence why they seem to blow so easy according to audio forums.

 

[tomelex]

The funny thing about fuses is, with almost no exceptions, the higher the resistance, the lower the noise of the power supply, if you can measure a difference at all. Adding resistance to the AC supply line does not degrade performance with exception of a smidgeon of top end, and/or a bad design that biases something off the raw rail voltage. Add resistance to the AC line and it will filter out high frequencies on the AC line and make the DC power cleaner. Even under heavy current draw it will still be cleaner.

So, when a fuse company claims their super duper audio fuse lowers resistance and hence is better, you know it is BS. Of course, I do get the impression Synergistic fuses are actually higher resistance, likely lower rated current than they claim, hence why they seem to blow so easy according to audio forums.

Well, IEC rated vs UL rated fuses operate differently as far as continious current, and the curves can be different between companies as well as far as the blow characteristic. These fuses are lots more complicated, like everything else, once you deep dive. UL blows at about 75% of current as the same ampere rated IEC fuse as far as continous current goes, so one thing is to replace UL with UL and IEC with IEC to keep within the designers idea of protection.

 

[radix]

Yes, no real clear evidence of their "scientific experiment" ahahhah. They showed directivity in resistance, and it is insignificant, but it is there, and that is where a lot of snake oil folks step up to the plate and claim its audible. They show their cryo stuff is a bit better, and there again they have a selling point to the audio masses that do not have much scientific background.

I do not believe their study shows directivity. It shows that if you take two measurements of the same fuse, they are different. It might be correlated with them turning the fuse a different way, but that is not causation. If they measured it 5 times each way and proved a null hypothesis, then I'd believe there is a difference in directivity. Otherwise, it's just an eddy current or power supply ripple or someone heating a TV dinner or a temperature change. And how stable was the reading when they made it? Did their 6.5 digit (or better) DMM stabilize? And how did they measure 3A or control for that?

If the measurements were not so far down in the noise and systemic experimental errors, then I wouldn't harp on this so much. But given what they measured and not knowing how they measured it, I don't think that PDF proves anything.

Marc

 

[tomelex]

I do not believe their study shows directivity. It shows that if you take two measurements of the same fuse, they are different. It might be correlated with them turning the fuse a different way, but that is not causation. If they measured it 5 times each way and proved a null hypothesis, then I'd believe there is a difference in directivity. Otherwise, it's just an eddy current or power supply ripple or someone heating a TV dinner or a temperature change. And how stable was the reading when they made it? Did their 6.5 digit (or better) DMM stabilize? And how did they measure 3A or control for that?

If the measurements were not so far down in the noise and systemic experimental errors, then I wouldn't harp on this so much. But given what they measured and not knowing how they measured it, I don't think that PDF proves anything.

Marc

Yes, as we all agree there are no details on this at all for the actual testing. However, there is nothing else out there that I know of, so I put this in this thread. Whatever system they used, they got the same results, directionality. Now, this could just be that after they measured one way, the process heated up the fuse just a bit, then when they measured the other way we see the results of the heating affect of the induced test current. Who knows?

I would not place a bet on any of it thats for sure, so I agree it is unproven but certainly could be used, and they did use it, to hawk their product.

 

[scott wurcer]

NO, I absolutely knew the context. Perhaps you did not and did not follow back to my original post. There is a big difference between "no directional component" and "the directional component is many orders of magnitude below audibility" from an engineering and truth standpoint. One statement stands up to scrutiny, the other does not.

We also don't need someone to interject (for instance) that Ohm's Law is not a fundamental law of physics into these discussions. Conductivity can be a function of many things. Take stress (as a tensor) for one and you could possibly find some microscopic directionality in some strangely doped metal.

 

[Alice of Old Vincennes]

For purist, take all fuses out and put a silver wire instead.

Don't know why I'm in fake snake oil mood (thus after having posted on the golden ear thread...).

And wire the silver to your temples. A "purist' human fuse.

 

[JSmith]

Surely "audiophile grade" fuses are a complete joke?

https://www.audiosciencereview.com/...agic-ultimate-premier-beeswax-shd-fuse.21449/

https://www.audiosciencereview.com/...ced-mqa-dac-review.17419/page-129#post-792657

I'd be quite concerned if a product I owned performed better or differently by changing a fuse... about the product itself.



JSmith

 

[Bob from Florida]

The notion that fuses change the sound in a way we can perceive is somewhat ludicrous. I have audio nut friends that have told me of fantastic improvements from fuses costing hundreds of dollars. I ask them what happens when the fuse blows - will they shell out that cash to replace. It would be one thing if the supposed audiophile fuses were $2, but the pricing structure is a huge red flag. Reminds me of an old Happy Days episode where the Fonz stated that BS makes the world go around.

 

[egellings]

I suspect that if you take any common inexpensive audio product, price it into the stratosphere and ascribe magical properties to it, that will imbue the product with magical audio qualities that audiophools will pay good money for. If it's that expensive, it's gotta be good, right?

 

[audio2design]

With our increasing wealth, more money than brains is an increasing affliction.