Today was my 2nd attempt at trying out Synergistic Research fuses. About 3 years ago when I had separates, including mono block amps, I bought a set of Blue fuses. One component had a mfg spec of 250mA and the retailer said go with 315mA. My two mono block amps each had a 6.3A. When I installed them one of them blew upon powering up. The retailer said we should go up to the next rating. I was a bit frustrated at the experience and didn't feel comfortable putting higher values in my expensive components. I felt these expensive fuses should be made to tighter tolerances than the cheap BUSS fuses I had been using. If I remember correctly, that was the actual argument that the dealer told me. They are mfg to tighter tolerances so a 5A SR fuse was almost dead-on 5A while a cheap fuse may actually be 5.3A or whatever. This also was a bit confusing at the time so I sent them all back.
Okay...3 years have passed and now I have a single integrated amp which has a 5A fuse. Much less to invest in the upgrade so I ordered an Orange. It came in today...installed....pressed power...on and off went the amp. DAMN!! I contacted the retailer and SR on the same email. This was a different dealer from 3 years ago. The retailer said I should go to the next value up. I said no and and they are waiting for the tracking info of my return shipment.
I did a quick search of my question before posting and saw a thread about the Red fuses and someone said they had to do the exact same thing. Is everyone putting higher rated fuses in their gear that is worth thousands of dollars? Is there no risk in this? I admit that I don't know what could actually happen from that. It seems that other things could burn up if a higher amperage fuse is in place. I am compelled to simply stick to the mfg specs for something that I don't understand because I don't want to create problems just from a simple tweak.
Should I let them ship me a 6.3A or just be done with this?
Yes, the fuse limits current into the power supply (exactly the idea) but the audio circuits do not see that
Correct because the big "musical transient" amperage that’s needed, does not come from the fuse, it comes from the reserves of "powersupply storage caps". The mains fuse side is a just a "trickle charger" (for an analogy) to top up those power supply caps, if they (the caps) run out of storage while playing music then **** hits the fan. And if the fuse is higher rated then your equipment is in big trouble
No need to replace a fuse at all even in a power amplifier. A well designed power supply is a buffer to anything happening before it including the fuse. Yes, the fuse limits current into the power supply (exactly the idea) but the audio circuits do not see that. In other words this idea of designer fuses is just another attack on lay instinct in order to extract money from you. If you really are concerned just wire by the fuse. Your house's circuit breakers should prevent the fire but, if something goes south be ready to replace the piece. I use to do this with power amplifiers but have stopped as it does absolutely nothing to improve sound quality. I proved that to myself with AB testing after an electrical engineer friend told me I was being silly. He was right. Even the Littellfuse audiophile fuses are over priced at $50.00/5. But, at least you can be sure they will meet spec. I see no reason to spend that kind of money on something sonically insignificant.
Downstream from the fuse you can use a regular film capacitor.
If you connect a capacitor from line or neutral to AC ground, anywhere on the AC side, no matter before or after the fuse, use a Y rated safety capacitor. Where it is in relationship to the fuse does not matter. One of these small capacitors failing will not take out the fuse, it will just increase the leakage current to ground to a dangerous level.
It seems like a very poor business strategy. Most, I would say 99.9% of the people would want to replace a fuse in their gear with a matching rating. This is what any MFG is going to recommend as they should.
It simply doesn't make sense to me. I can be very cynical but I don't think the entire industry is a scam where they are simply taking cheap fuses and painting them or whatever. I believe there is engineering, R&D, etc. involved, but I don't understand why their fuses cannot handle current the way a 'stock' fuse can. This should be priority #1 in designing a fuse.
I DO NOT believe that all 'stock' fuses have incorrect specs and are allowing different values of current than they are claiming. I believe the mistake lies with these high end fuses. So if that is the case, why don't they correct this where people don't have to send back blown fuses and then try plan B with a higher value fuse. This has left me without confidence in their product.
Another rather unpleasant thought is that one reason designer fuses blow when they shouldn't is that the makers of such fuses have one goal in mind, to maximize profits. That would entail buying the cheapest fuses from the cheapest manufactures ($.05 each?), adding their "magic" touches, and then selling them for the most profit possible. Having to replace a few of the really defective ones, no biggie.
I'm confused (get it)? What am I missing? OP stated 250mA fuse (1/4 of 1A) Suggested a 5A (20 times the mfg suggested current and still blows?) Did I miss something or is something really wrong here? I'm not an electrician, but I did stay at a Holiday Inn last night. AB
@grannyring Do you have any more detail on the use of breakers? I've never tried them, but on the face of it it does seem like a good idea and I'd like to explore.
clearthink1,213 posts04-28-2021 12:37pmdletch2"Typical breaker has 3x or more the resistance of a fuse for a given current rating at room temperature"
That may be accurate, true, and valid in you're country but it is completely false, mistaken, and wrong in many parts of the world and I even doubt it's truth where you live.
I see you are up to your lies again @clearthink. Or should I say trolling. Are you so obtuse to think it is not obvious? You make this same response to my posts, we are up to what 5 now? You NEVER back up your words with any facts. That would imply you are lying. The question is, WHY ARE YOU MISLEADING PEOPLE HERE? It does not matter where you live, breakers have more resistance than fuses.
@twoleftears thank you. Littlefuse (or Buss) I trust, snake oil fuses not so much. i tried expensive Furutech fuses in my amp, which kept blowing. It seems to be a common experience with the expensive fuses of all brands, I can’t quite see why that would be.
This company makes some good breakers as I have used 3A, 5A, and 10A in amps, preamps and DACs in the past. Tube Research Labs used to use these in their tube amps and preamps. Eaton Heinemann
dletch2"Typical breaker has 3x or more the resistance of a fuse for a given current rating at room temperature"
That may be accurate, true, and valid in you're country but it is completely false, mistaken, and wrong in many parts of the world and I even doubt it's truth where you live.
Have you tried a nice breaker as an on/off in your builds? If not, you have no idea how much better they sound than a fuse. Some smart builders use them. I use them all the time. I have spend the time and effort to compare.
Typical breaker has 3x or more the resistance of a fuse for a given current rating at room temperature. Audio is typically running at a fraction of rated power, so fuses typically are not even getting warm, and low power equipment normally has a fuse rated many times its requirement.
I have tested it. No fuse sounds best - bypassed. High end fuse sounds next best. Stock fuse the worst. So simple to hear anyone open minded enough can hear it. Build gear with high quality on/off breakers to avoid the whole fuse sonic bottleneck.
Lots of over-the-top fear based posting here. Sorry, just is.
There is just so much to deal with in that question, adn the related storeis, that my head spins. Simple answer: generally no. And the ONLY time you should deviate is if you understand the reason the engineering, and then you would not b asking. The story about the fuse being spot on 5A and therefore sounding better is just so incomprehensibly flawed that i wont even begin. Fuses make no difference at all, unless they blow. Test it, blind and matched, yourself. use the same value fuse. If it blows think about the turn on sequence. Some amps (like everything i ever designed0 must have the low level circuitry stabilize for, oh, 60 seconds, before the main power is turned on or a fuse WILL blow. All this ought to be in the manual, which you have read, right?
Go get yourself a box of assorted fuses at your local hardware store. Try them at different values. If you try higher than the manufacturers advice, keep your eyes, ears and nose open for signs of trouble. Make sure they're not only the right current value, but also the right speed (slow or fast) as per specs
If these fuses blow as well, contact the equipment manufacturer. There's something wrong with your equipment. If these fuses don't blow, you know the problems lies with your expensive fuses. Have a talk with *that* manufacturer.
In the latter case, I'd stick with regular fuses of the specified values. Tweaks are nice, but can never be detrimental to health or safety.
The fuse or circuit breaker in your house is to protect you and your house.
The fuse in your equipment is to protect its components.
In both cases you should never use a higher value. In the house it is to stop drawing too much current through the wiring (i.e. the total number of power points in the circuit) or in the case of a circuit breaker to also monitor earth leakage; in your equipment it is to stop it drawing more current than the components are designed to handle.
Perhaps the manufacturer was conservative and you could go higher, but I suggest considering the cost of equipment it isn't worth the risk. In many ways it is like overclocking your computer. In both cases you are better off buying something else.
First we need to recognize that the amperage rating on the fuse is the amount of current that the fuse can handle. The higher the rating the more current it can handle. Also you want to run the component in question for a period of time with the manufacturers stock fuse at high volume levels at times. If nothing bad happens then I think the risk of replacing that stock fuse with a higher amp rating than the component spec ala @millercarbon, slo blo fuse is low. However, I would highly recommend and would consider it mandatory that the component be connected to a robust power conditioner or regenerator with a decent power cable and that it is well grounded.
If fuses are not manufactured correctly they will trip when they’re not supposed to. It’s no surprise the boutique fuse salesmen do not provide time current curves or melting energy. Going up in fuse sizes increases the probability of excessive heat energy making its way through the power supply and other circuits. Not a good thing if you want your expensive equipment to last past the warranty period.
I would not put a higher value fuse in your gear try to find a vintage fuse supplier they were made a different and more robust way and they sound better too.
Of all the snake oil BS out there in audiophile land, these so called audiophile fuses stink the worst. And as far as the rated fuse goes, NEVER, repeat NEVER replace the blown fuse with a higher rated fuse unless you just really don't care about your audio gear. Design engineers specify a fuse that will handle normal AND peak demand loads for a safe period without blowing. That fuse blew for a reason. It might, maybe, possibly, have been a defective fuse. The chances of you getting two defective fuses in a row is miniscule, so if the replacement fuse blows, you have an equipment problem. If you like spending money, go ahead and put a higher amp fuse in. The repair shop will love you for it.
When I installed them one of them blew upon powering up. The retailer said we should go up to the next rating. I was a bit frustrated at the experience and didn't feel comfortable putting higher values in my expensive components. I felt these expensive fuses should be made to tighter tolerances than the cheap BUSS fuses I had been using. If I remember correctly, that was the actual argument that the dealer told me.
This is what is referred to as a lie. Obviously they are not manufactured to tighter tolerances, reasons already given.
So what are you left with:
Fast blow marked as slow blow?
Poor quality control?
Up-marking the fuse, i.e. taking a 3A fuse and rating it 5A. Why would someone do that? Well that will make the fuse run hotter and will increase the fuse resistance. Bad thing right? Nope, More resistance in the AC line, and the noise will always drop a bit. Noticeable? Probably not. When the fuse gets hot, the resistance goes up a lot. Noticeable? ... who knows. But .. but .. but .. thermal modulation! Well you don't want thermal modulation for a speaker fuse in a speaker line. In a power line that will give you even more filtering.
Don't you wish the manufacturer had their products validated by a 3rd party lab? ... like any product that fulfills a safety function should be! Probably it is .... by the company that makes it for $0.10 ...
Downstream from the fuse you can use a regular film capacitor.
I found a good quality film cap downstream from the fuse wired across live and ground sometimes produces an audible improvement in the sound. A Y cap upstream from the fuse not so much.
dhite71 OP This kind of dangerous advise below is total lunacy and could only come from a "snake oil fusers" mouths, which all have no concept of electronics whatsoever.
Me being one of the few actually has common sense, when mine blew I didn’t go up one baby step I doubled the damn thing. Why not? There are guys soldering wires straight across simply because it sounds better.
"
I value what the MFG recommends. They advised me to never put a larger value fuse in any component as this is how the safety features are designed. Seems some of us are finding no issue with that strategy but I am not comfortable to roll the dice with my gear. "
I tend to agree with your sentiment.
Do a sanity check. Get a couple of manufacturer rated regular (i.e. "non-audiophile") fuses and try them. If they don't blow and your audiophile fuses blow, the fuses are at fault and send them back.
If you blow the regular non audiophile fuses that are rated per your manufacturer specifications, you need to contact your manufacturer.
If a fuse blows when you power up you either have a short which means no matter what value fuse value you try it will do it's job and blow, or the transformers allows an inrush of current which temporarily exceeds the current rating of the fuse. Slow blow fuses are made to deal with this issue.
Have a look and see in the OEM fuses are slow blow fuses - they probably are.
Do not exceed the manufacturers recommended rating on the fuse no matter what the armchair electrical engineers say. They've obviously never designed electrical equipment or even owned a soldering iron, and they will most certainly not cover the cost of expensive repairs should something go awry.
@auxinput I did get the correct SLOW blow fuse so this was not the issue. I value what the MFG recommends. They advised me to never put a larger value fuse in any component as this is how the safety features are designed. Seems some of us are finding no issue with that strategy but I am not comfortable to roll the dice with my gear.
Littellfuse makes a 285 series in the small 5x20mm size that twoleftears is talking about. It is available in either gold-plated or rhodium-plated end caps. The problem is availability. Both Digikey and Mouser have them in the catalog, but only actually have very limited sizes in stock.
As far as the OP issue is concerned, I am wondering if he is using a FAST BLO fuse in a device that really needs a SLO BLO fuse. A FAST BLO fuse can blow really fast on devices that have a big inrush of current from the transformer (i.e. a device that does not have a soft-start circuit). In this case, switching to a SLO BLOW fuse should solve the problem.
Fuses (and circuit breakers) are rated such that they blow or trip
before any part of the circuit gets to a dangerous current. You rate the
fuse or breaker based on the lowest current rating of all the devices
and wires in the circuit .
In your case, the manufacturer of the connection unit determined
(somehow) that the "weakest link" in that circuit can only draw 5A
before it exceeds its limits. Putting in a 13A fuse would thus allow
that weakest link to draw almost 3 times what it may be designed to,
which leads to increased heat and then fires.
If you double the size of the fuse, there is a small risk that the fuse will not blow if the transformer and circuit are not large enough to pull the amount of current the fuse is rated for (even if there is a short). This is similar to the scenario where an amp is pushed so hard that it clips (essentially runs out of gas because the transformer/power supply is not large enough to supply the expected current).
Me being one of the few actually has common sense, when mine blew I
didn't go up one baby step I doubled the damn thing. Why not? There are
guys soldering wires straight across simply because it sounds better.
I highly recommend that you DO NOT do this. This kind of thing is never good advice. Anything you do similar is AT YOUR OWN RISK.
I would think you should have gotten the message by now. Making reliable accurate fuses requires a lot knowledge, science and experience which little companies can not afford. Go out and get a tin of Buss fuses the right size and be happy, you will not find a better fuse anywhere. If anyone thinks those designer fuses improve sound quality it is purely psychological. Spend your money on better equipment not garbage like designer fuses and cable elevators.
If only common sense were actually common..... the whole point of the fuse is to not burn your house down. Has nothing to do with protecting your precious expensive equipment. For proof of that look no further than all the millions of people who have blown resistors, tubes, transistors, fill in the blank, and not blown a fuse. Look how many amps fail while the fuse is just fine. That is not what they are there for. They do not protect against surges. All they are designed to do is in the event of some dramatic short that might cause the component to go up in flames the current draw will cause the fuse to blow first.
That is all.
Once you understand this then, oh but wait no common sense.
Okay, try again. Why does the fuse blow in the first place? They are all made out of very thin wire. The idea is the thin wire gets hot and burns out first. Without the fuse if for any reason the component draws more current than it is wired to handle, well at that point a whole lot of wires could just possibly get hot enough to start a fire. The whole point of the fuse is to blow before this happens.
Committees and politicians and fire departments - pretty much everyone but audiophiles - then gets involved and that is how we wind up with all these screwy tiny little amperage ratings, in a hundred different values, when really all we need is one wire somewhere that will blow before the rest get hot enough to burn.
Me being one of the few actually has common sense, when mine blew I didn't go up one baby step I doubled the damn thing. Why not? There are guys soldering wires straight across simply because it sounds better. I think it is great Synergistic will replace for free any that you blow. But I don't like the hassle and I know there is ZERO RISK so I bump em all up. Some of em are probably 3x, 4x whatever the stock fuse was.
We now return you to our regularly scheduled neuroticism.
To stick with the MFG recommended rated fuse was my feeling and I am certain of this choice now. I didn't intend for this thread to spark the debate of whether a fuse offers a sonic advantage. I would like to know if all those high-end fuse lovers, specifically from Synergistic Research are bumping up to the next amperage. Is this a quality issue with SR? Are there other brands that are more accurate in their rating where if I buy a 5A fuse it will work just like my Bussman 5A fuse regarding the protection limit?
I have not used the Synergistic fuses but I can assure you fuses do make a difference. I have tried $40 Furatech rhodium and the difference is startling. ... Try this: Wrap the glass of your fuse with a few turns of PTFE (plumbers tape) or even masking tape. Avoid the end caps. Now listen again.
If something happens causing a 5amp fuse to blow, it’s very likely the same fault will also pop a 6.3amp fuse. Ask Synergistic to confirm this in writing for your amp should you have an issue. The manufacturer may not endorse this however.
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