I’ve bought 5 Audio Horizons Platinum fuses a couple of months ago, for my amps, speakers and DAC. Three days ago, coincidentially, the 5A fuses on my mono amps (Rogue Apollos), blew at the same time on start up. Replaced them with the OEM fuses, and everything works again. I have a very good electrical installation, with independent lines for each amp, a no surges or anything strange occurred. My speakers, Evolution Acoustics MM3s are always ON, and nothing happened to the fuses on them. I emailed Joseph Chow inmediately and his response was to send the fuses back to him (at my cost, I live in Ecuador...), to repair them for $70/each, plus shipping. I have paid $138 for each fuse in October, and no warranty?... what a shame!!! Won’t buy these fuses again, NEVER!!!
Mr. Chow never asked anything, just asumes that it was my problem, not a pair of defective fuses... almost impossible to believe that two fuses of the same batch blew at the same time... such a coincidence!!! I’m in the 0.01% of the losers group... and the winner is...Mr. Chow!!!
Obviously, no storms, surges, nothing strange happened.
As for voltage surges how would you know? Not all voltage surges are caused by storms.
I notice the input voltage rating for the amps is 115Vac. What is the avg mains AC voltage at your residence? Is it stable or does it fluctuate? Does it ever get above 126V? What was the voltage at the mains power receptacle outlets the day you powered up the amps and the AH fuses blew? I doubt if you know...... Who checks such things.
Am I defending the Audio Horizons fuses? NO. Just giving the guy at AH the benefit of doubt. Just a guess the 5 amp OEM slow blow fuses that came with the amps have a longer lag, delay, time than the AH fuses.
More than likely the two fuses blew due to high inrush current when you first turned on the amps that particular day. The high inrush current event is caused by the DC power supply charging the electrolytic caps. Do the Amps have a soft start circuit? If not each amp could draw well over 50 amps for an instant when you first flipped the power switch on. Did you wait a few seconds before turning on the second amp? If not you may have created a voltage surge on the mains power utility transformer feeding your home.
At any rate I would say again the OEM fuses more than likely have a longer, lag, delay, time for inrush current before settling back to normal than AH fuses do. That is what a slow blow is made for.
The worse thing you could do is increase the ampere rating of the fuse to a higher size. That will affect the overload protection for the equipment it is meant to protect.
tubegroover I get the program Geoff loud and clear. What isn’t clear because it hasn’t been made clear is when the warranty clock started and when the fuses blew other than immediately upon installation. Bottom line is IF the tube purchased is the same value as what is specified by the manufacturer why is it failing so early but MOST important to the point I attempted to make, did Mr. Chow even inquire or ask questions or was it no problem, ship them back and I’ll "repair" them at 70.00 each plus shipping. The fuse blew when installed. Clearly this is more than about warranties. What don’t you get about that?
You thought about it long and hard? Whoa! I trust you didn’t hurt yourself. I guess I’m not everyone’s cup of tea. That’s the way it goes sometimes. Comments accepted. Like the flowers.
For those of you that posted you increased the size of your audio grade fuse by one size because the correct size blew, here is something you may want to consider. When the designer/manufacture sizes the ampere rating of the fuse to protect his equipment the ampere rating is usually higher than the power consumption of the equipment. It might be 110%, 125%, 150% 175%, or 250%. It can be as high as 300% of actual FLA of the piece of equipment and still meet electrical safety standards.
If you look on the back panel of the piece of equipment the manufacture should show the power consumption of the piece of the equipment and the AC voltage rating it is rated at.
If it is given in watts or Va just divide the watts/Va by the voltage. Example of a tube power amp 330 watts @ 120V. 330/120 = 2.75 amps FLA. Size of the line fuse? For a tube power amp it will more than likely be a slo-blo fuse. Ampere rating, depending on how beefy the power supply is at least 125% of the FLA. 125% of 2.75A = 3.4 amps 150% of 2.75A = 4.1 amps 175% of 2.75A = 4.8 amps Good chance the fuse will be a slo-blo 4 amp 250v fuse.
What is the percentage if the ampere rating is increased by 1 amp? 4A to a 5A fuse. 175% of 2.75A = 4.8A 185% of 2.75A = 5.09A
So you may be increasing the lag, delay, time for startup inrush current so the fuse does not blow, but what are you doing for the overload current rating protection of the piece of equipment?
I don’t recall anyone going up a whole number in fuse rating. Especially if the fuse rating was a low number. That would be taking an unnecessary risk.
I don’t recall anyone going up a whole number in fuse rating. Especially if the fuse rating was a low number. That would be taking an unnecessary risk.
@ geoffkait ,
It’s a power amp that is spec’d, by the manufacture, to use a slow blow 5 amp 250V volt fuse. What size would you recommend to the OP moving up to with AH fuses? http://www.rogueaudio.com/documents/ApolloManual.pdf
geoffkait Said:
This could just be a case where you need to increase the fuse rating, as others have noted.
Yeah, but ordinarily people increase the value by only .25A or maybe .5A not a full Amp. But maybe someone somewhere has, who knows? The other thing is no one seems to know exactly WHY the aftermarket fuses blow. I also recall even stock fuses blow prematurely so who knows?
Yeah, but ordinarily people increase the value by only .25A or maybe .5A not a full Amp. But maybe someone somewhere has, who knows?
Do you think a mere 1/4 amp increase would be enough for the OP to try? Or maybe a 1/2 amp? Remember we are assuming that start up high inrush current caused the AC line slo-blo 5A fuse to blow in each mono amp.
So what increments in ampere ratings do AH fuse sizes come in above slo-blo 5 amp 250V? Do they, ( AH), make a slo-blo 5.25A 250V or a slo-blo 5.5A 250V fuse?
Thank you jea48 for the information on the what, why and how of fuse ratings. That helps me and I am sure others make a more informed decision. I have aftermarket fuses with the called for manufacturer rating. But I have thought if I have a problem that I may go up a notch. Now I know more about what I would be doing. Thanks
For a slo-blo fuse, 1/4 amp, it could be overloaded 135% up to 60 minutes maximum before it blows. 0.25 X 135% = 0.34 amps. 0.25 amp overload condition of 200% for up to 120 seconds maximum. 0.25 X 200% = 0.5 amp
Replacing a 1/4 amp with a 1/2 fuse.
1/2 amp fuse. 1/2 amp, it could be overloaded 135% up to 60 minutes max before it blows. 0.5 X 135% = 0.68 amps 0.5 amp overload condition of 200% for up to 120 seconds maximum. 0.5 X 200% = 1 amp.
Just stay away from the fuse snake oil, it’s all BS just to get your dollars.
@georgehifi
While I’m inclined to agree with you completely, I’m curious as to your opinion as to why so many folks (on this forum and others, such as very recent postings on head-fi where the Yggy fuse is concerned) claim to *hear* an improvement when switching from a manufacturer supplied fuse to a boutique aftermarket fuse.
purport to *hear* an improvement when switching from a manufacturer supplied fuse to a boutique aftermarket fuse.
Simple answer to that one, "they don't". If you know your ac/mains theory, it's just not possible.
What they do hear is "expectation bias" waiting for it to arrive after spending $130 on a $2 fuse. Or their replacing an old fuse that's had too many turn on surges over time and carbonising and getting ready to blow like this pic below. There's no way they could reliably pick the difference in a blind A/B.
Go back through the fuse threads and you'll see that this argument has already been shot down. Properly made fuses should show no signs of wear unless they are cheaply made. All they have to do is blow when required.
Now imagine the silliness of an argument that purports that hundreds, if not thousands of people succumb to expectation bias when it comes to fuses. Now attribute that silliness to the people who bring it up over and over again.
Go back through the fuse threads and you’ll see that this argument has already been shot down.
Really!! think about it. Your comparing your new "boutique" $$$ fuse to an old $2 original one that’s seen many turn on cycles from when the unit was new, and is carbon’ed up and bent out of shape as in the pics. (left is new, right is after many turn on cycles) https://i.stack.imgur.com/0uqWX.jpg You have no argument, all you have is " expectation bias".
Expectation bias, like placebo effect or any other psychological effect you wish to name, can easily be eliminated from consideration as the cause by careful testing and listening. It’s not really that difficult. It’s not rocket science. 🚀 In fact, blind testing is one of the war horses 🐎 of the pseudo skeptics Handbook. You won’t see the detractors ever actually getting down to brass tacks, even their beloved blind testing, as they’d rather fight than switch. I don’t expect to see an apology 😢 coming any time soon from George or any of the other pseudo skeptics. What would they say to the other pseudo skeptics? “Gee whiz, guys, I musta buckled under the pressure.” I’m little surprised the naysayers haven’t pointed to aliens or group hypnosis or even some massive global conspiracy as the culprit.
Expectation bias can be easily eliminated by careful testing and listening. It’s not really that difficult.
And it's obvious that you can't do either, especially when you state they are directional.
All your maybe hearing is an old fuse (pictured) that seen too many turn on cycles, verses a new fuse, you may as well just get a new $2 fuse instead of the $130
boutique
one.
1 and 2 are good that have not been stressed by overloads or a high voltage transient event/s.
4 and 5 are clearly blown.
If your asking no. If your telling wrong. They are the same fuse over time, and none are blown, all functional just shown the decay that happens over too many switch on surges. The parts you think are open circuit are in fact just white carbon build up on the resistance wire. You can search for the origins, as I posted these up years ago, when all this fuse snake oil started.
1 and 2 are good that have not been stressed by overloads or a high voltage transient event/s.
4 and 5 are clearly blown.
If your asking no. If your telling wrong. They are the same fuse over time, and none are blown, all functional just shown the decay that happens over too many switch on surges. The parts you think are open circuit are in fact just white carbon build up on the resistance wire. You can search for the origins, as I posted these up years ago, when all this fuse snake oil started.
Cheers George
Where’s the Beef? https://www.youtube.com/watch?v=Ug75diEyiA0 With out some technical information explaining the fuse through the five stages, shown in the picture, the picture is meaningless.
For all I know it is a picture where the fuse was subjected to an overloaded condition beyond its’ ampere rating for a period of time. Again supply the testing technical data for the picture.
I have never in my lifetime seen a fuse that tests good, measures continuity, that was installed in a circuit, operated within the manufacture’s ampere rating, that looked anything like the picture in the Link you provided. Have you? Has anyone reading this thread? Anyone??
I own audio equipment I bought in the 1970s, ( with original fuses), and the fuse element wire inside the glass fuse still looks the same to me. I have owned equipment from the 1950s, and 1960s where the fuse element wire inside the fuses didn’t look like the picture in the link you posted.
Don’t worry. It’s obviously some new ill-conceived troll tactic designed to make everyone feel worried. Don’t worry. Be happy! 😛 There is no joy in Mudville today. 😥
For all I know it is a picture where the fuse was subjected to an overloaded condition beyond its’ ampere rating for a period of time.
Believe what you want, next time you switch on a high current draw amp, see if you can see the resistive element inside the mains fuse move and bend a little. That’s why in an amp with no problems, if the old mains fuse mysteriously blows, it’s 99.999% of the time at the switch on surge
jea48 said: For all I know it is a picture where the fuse was subjected to an overloaded condition beyond its’ ampere rating for a period of time.
Believe what you want, next time you switch on a high current draw amp, see if you can see the resistive element inside the mains fuse move and bend a little. That’s why in an amp with no problems, if the old mains fuse mysteriously blows, it’s 99.999% of the time at the switch on surge
Never ever do this if the manufacturer hasn’t used it, or you may cook many components, instead of a couple if it goes faulty.
Confused?
You show a picture which sure looks like a fast acting, fast blow, fuse in a thread where the discussion is clearly about slo-blo fuses and you call me confused. Then you go on and talk about a fast acting fuse’s ability to handle high inrush current. How many power amps do you know of that use a fast acting AC Line fuse?
Oh well...... Try this type of slo-blo fuse in your power amp/s. It has built in wiggle room.
Still confused, and testy as well. Then you should have directed this directly at the OP, not just as general comment at me or anyone’s amp or amps, to give them some amperage "wiggle room" that just plain dangerous.
Taken from the Electronics Engineering hand book: "Fuse ageing by switching loads.
The fuse wire gets hot and expands when current flows. At high temperatures, oxidation may happen, which weakens the wire mechanically, and may be electrically, too. Switching on/off a load means the wire is bent each time. This stress may cause a blown fuse at some point even when the current never exceeded the threshold."
Oh well...... Try this type of slo-blo fuse in your power amp/s. It has built in wiggle room.
was in response to your comment.
Believe what you want, next time you switch on a high current draw amp, see if you can see the resistive element inside the mains fuse move and bend a little.
Even the repair department is cashing up on this snake oil hysteria. Next they'll be charging extra for special vacuum sealed postage, so you know your getting them fresh.
Back when I was a dealer for the original $16 Intelligent Chip, which was good for only 10 treatments before it ran out of steam, I offered a recharging fee of $25. Was that wrong? 😳 Not to beat a dead horse, all the angst and anger regarding the Audio Horizons fuses could have been avoided by staying within the 30 day guarantee period. Problem solved.
Dear miko71, I think that you are disparaging Ecuador... Am I wrong? if you read my original post, you can see that the only fuses that failed were the AH ones. When I paid that kind of money for a fuse, I thought I was buying QUALITY, not just audio quality. The quality of the product was bad, but customers service quality was AWFUL.
An Audiogon member just brought this thread to my attention. I want to explain my approach to handling the situation that started this discussion.
1. The customer reported that fuses in both amps opened (that is, they protected) at the same time when the amps were turned on. Two simultaneous failures indicated that some event - power surge or other - at the customer’s installation had occurred. The fuses were exposed to some force outside their operating range and they worked as expected - they protected.
2. The warranty period had expired. I offered to replace the fuses at a reduced price. I asked the customer to return the spent fuses because I wanted to inspect them to confirm the report.
There is nothing more to the matter. Unfortunately, the customer has said he feels ill served by the warranty policy and my offer to supply replacements at half price outside of the warranty period. I regret that he feels so. I tried to accommodate him in a situation that has not occurred before.
Once again, an exact copy of the email that I’ve received from Mr. Chow:
”Hi Leo,
That's weird, no sure if the storm around your area cause the power surge. Is this happening right after power up? We see less than 0.01 % rating failure in our sales record and we only provide one month warranty. However, please check the current rating and either slow or fast blow in your original stock fuse.
We can reworking your fuse once it return and cost $70 each plus shipping.
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