Fuses that matter.


I have tried six different fuses, including some that were claimed to not be directional. I have long used the IsoClean fuses as the best I have heard. No longer! I just got two 10 amp slow-blows WiFi Tuning Supreme fuses that really cost too much but do make a major difference in my sound. I still don't understand how a fuse or its direction can alter sound reproduction for the better, but they do and the Supreme is indeed! I hear more detail in the recordings giving me a more holographic image. I also hear more of the top and bottom ends. If only you could buy them for a couple of bucks each.
tbg
Tbg,

In general, I do not advocate people open up their expensive gear and make a tweak in the interest of better sound unless they really know what they are doing. Accidents happen, and there are many other much less risky ways to tweak for better sound. In some cases, vendors might even void a warranty if the device is opened up by anyone not authorized.

For someone who truly knows what they are doing, more power to 'ya!
Mapman, I like the IMHO. As long as people respect the fast versus slow distinction and the amp value on the stock fuse, experimentation is perfectly safe. Why you would advocate avoiding the fuse tweak, I don't understand.
Hopefully, people listen to AL in that that is really the thing that "matters" most with fuses.

How different ones in good operating condition sound is a distant second IMHO. Lots of other ways to tweak ones system without putting it at risk IMHO.
Simply put, replacing a slow blow with a fast blow risks "nuisance" (unnecessary) blows, while replacing a fast blow with a slow blow risks extensive damage to the equipment (and conceivably even the possibility of a fire) if a fault were to occur.

A substantial change in the "nominal melting" (amps squared-seconds) parameter of a fuse, which would result from a change between fast and slow blow types, amounts to a design change in the equipment, which should not be done without careful analysis. And the information about the design that would be necessary to do that analysis will generally be unavailable to the end user.

Regards,
-- Al
MY BAD; I meant to say, "One might replace a Slo-Blo fuse with a fast blow type...." Sure would be nice, if this, "IMPROVED" site, still allowed for editting a post.
"No doubt some boutique fuse manufacturers are just supplying the same product for both fast and slow, but that's another story." On what are you basing that assumption? One might replace a fast blow fuse, with a time delay type, BUT- it would be VERY foolish, to do the opposite. ie: Generally; time delay is necessary, to allow a power supply's caps to charge. Rail or B+ fuses need to respond immediately, should a downstream device short/draw high current, or serious damage can occur elsewhere in the unit's circuitry.
slow-blow vs fast-blo?

We all know fuses do make a difference (at least those commenting here). And I presume most of us -when we say fuse upgrade- are buying slow-blo.

But what if its fast-blo fuses that are best? Putting aside what the manual says, has anyone compared both types of the same value and brand?

No doubt some boutique fuse manufacturers are just supplying the same product for both fast and slow, but that's another story.
Turboglo and Vhiner, most reviewers don't have the benefit of manufacturers coming to their listening room and setting up already brokenin equipment and setting the room to optimize their equipment. And, of course, those who get this benefit may be listening to "special" pieces.

I just notified a manufacturer that I know the very special Urushi caps he and others use, take hundreds of hours to break in and that I would probably need a month and a half's access to his component.

I am also now using exceptional interconnects and speaker wires that may take 1000 hours of use to reach their best and may take two days to recover from being moved from one component to another. How I would love a piece that sounded exactly the same at 15 minutes and two years.
Turboglo,

I can't think of a single audio component I've ever owned or listened to that didn't sound better after a few days of continuous use. Witness how reviewers at shows who return to rooms usually notice improvements.

I agree that it may be counter intuitive to some and that the Hifi Tuning fuses require significant break in time. Too many audiophiles try out equipment like they choose their beer; quickly. However, the ears aren't the tongue and properly converting electricity into music is still a mysterious process.
The following is my experience replacing the standard fuses in my integrated amplifier with Hifi Supreme Tuning Fuses. The amp is an ARS-Sonum Filarmonia. It has maximum output power of 30 watts RMS per channel at 8 ohms. Its output stage uses a pair of E34L pentodes per channel, in push-pull configuration. It is an outstanding amp paired with Merlin Master VSM's.

There are three fuses. The main power fuse is a slow-blow 4 amp, and the two internal fuses are also slow-blow rated at 500 mA.

I initially purchased only the main power fuse, as I had heard that it has the most dramatic impact. From the moment I replaced the stock fuse, the improvement was clear and continued to improve over the next week. With that success, I decided to spring for the two internal fuses. Unlike the immediate improvement with the power fuse, my initial response to the new internal fuses was, "Wretched!" It was so bad that I immediately shut the amp down, took the tubes out, disconnected all cables, opened up the amp and switched the direction of the fuses. I believe that this improved things slightly. But still it was virtually unlistenable for the first ten hours. By 15 hours, it had started to relax a little, although still extremely congested. By 20 hours it was just barely starting to sing.

I've now got about 30 hours on these new fuses and they're sounding pretty darn good. At this point I would say that they are a definite improvement over the stock fuses. Primarily, the soundstage seems to be more clearly defined. I have more of a sense of the depth and boundaries of the original recording environment. Instruments are also more realistically "shaped."

This is perhaps the most dramatic burn-in phase of any new component I've added to my system: from wretched to pretty spectacular. Maybe it's the 99% silver wire. I am expecting continued improvement through 100 hrs. based on what I've read.

I'm writing this for anyone who has purchased these and have not had the patience to let them burn in. I was tempted to give up at 10 hours, given my experience with the immediate improvement with the main power fuse. I suppose, however, this makes some sense. I have very little technical knowledge, but the current running through the signal path must be much lower than the current running through the main power fuse, hence the longer burn-in time??

It always amazes me that manufacturers do not state clearly and unequivocally that their product WILL sound inferior until after XX hours of playing time. I bet that plenty of "non-believers" in the burn-in phenomenon have judged products inferior before giving them a fighting chance.
Almarg, i wonder if any manufacture has ever gone about choosing a fuse value this way. I know with certainty two who went to a different value when the first was blowing too often. I think it is more like civil engineering with a big safety factor. After all why not start low and work your way up?
Al,

That's quite a can of worms you just opened. ;-)

I have sent an email to the owner of Hifi Tuning. I'll post if I get a response.

V.
This might be a good time to remind folks that quite a lift in sound quality can be achieved without buying ANY new fuses at all. What are the odds that the existing stock fuses in any given amp or speaker were originally inserted in the correct orientation? If you guess 50% you're correct. So, the trick is to make all the fuses in the system be the correct orientation. The way to do this is reverse the direction of fuses one at a time, listening each time. Reverse the first fuse direction - If the sound gets more harsh and unnatural sounding put the fuse back in the way it was. If you are uncertain which direction is correct by ear, leave as it is for the time being and proceed to the next fuse. Reverse the direction of the second fuse and evaluate the sound. When all fuses have been evaluated, you should observe the system sounds more natural and less distorted and harsh than before you started to change fuse directions. There still might be some fuses that are not in the correct orientation due to uncertainty during evaluation. Repeating the whole procedure should uncover any fuses that still remain incorrectly oriented.
Hi Vance,

I don't doubt that these companies COULD replicate the protection characteristics of the stock fuse. However, different designs of just about any electronic product differ in terms of their design goals and philosophies, and how the tradeoffs that inevitably must be made between many different parameters are prioritized.

As you've seen in the datasheet, even something as simple as a fuse has a great many different specifiable parameters. In addition, earlier in this thread links were provided to papers prepared by HiFiTuning which presented several pages of comparisons between various measurements of various makes of fuses. The data differed widely among the different fuses. (Although I commented that IMO none of the differences appeared likely to be quantitatively significant, and even if some of them were quantitatively significant in some applications, I saw no reason to expect the resulting sonic effects to be consistent among different component designs, and among different AC line voltages).

So given the many parameters that are involved, and the diversity of measured data for different fuses having similar current ratings, it seems to me that while the aftermarket fuse manufacturers COULD replicate the protection characteristics of this particular Littelfuse, I would have my doubts that they DO closely replicate them. But as we said earlier, it will be interesting to see what they provide in response to an inquiry asking for breaking capacity and nominal melting numbers.

Here's another thought, though, that is suggested by the numbers in the Littelfuse datasheet. On the first page, take a look at the numbers in the table of "opening times" (i.e., the amount of time required to blow) that are shown at the lower right. Note in the entries for 275%, 400%, and 1000% that the range of specified opening times for a given fuse and a given overload is huge. For example, for fuses rated between 8 and 20 amps, and overloaded to 400% of their rating, the blow time can be anywhere from 0.15 seconds to 5 seconds. That is a huge possible variation from fuse to fuse. Which suggests the likelihood that many other parameters, for which only a nominal value and not a range of possible values are specified, could also have wide fuse-to-fuse variations.

So it seems to me that a useful experiment may be to simply buy a bunch of fuses that are the same make and model as the stock Littelfuse, and compare sonics between them. Who knows, maybe you'll find significant sonic differences between them, and perhaps one or more of them will provide sonics comparable to what the aftermarket fuses would provide.

If you do that, btw, it might be best to split the order among multiple distributors (e.g., Digikey, Mouser, Newark, etc.), which may increase the likelihood that the fuses you try come from different production runs.

Regards,
-- Al
Al,

I really should refrain from posting after 11pm. My attention to detail declines markedly. Yes, I meant 5x20mm.

I'm just curious as to whether you think one should generally be concerned with the specs of after market fuses produced by reputable companies like Synergistic and Hifi Tuning? The Littelfuse for my amp costs a mere $1.67. Surely, we can't be talking about a product that is beyond Hifi and Synergistic's ability to re-produce, assuming there would be any profit in it for them.

Does the data sheet reveal anything to you that would indicate how it is "special" or "out of the ordinary?" I ask because you clearly know more about this technological data than I do.

Regards,

V.
Thanks, Vance. Here is the datasheet. (I assume you meant 5 x 20 mm, not 5 x 22). Looks like the breaking capacity/interrupting rating (related, as I said, to assuring that blowing which occurs under fault conditions occurs in a safe manner) is spec'd as 1500 amps @ 250 volts, and the nominal melting spec (related to the likelihood of unnecessary blowing at turn-on) is 515.5 amps squared-seconds.

Regards,
-- Al
Al,

I am no engineer, so I'm certain I poorly paraphrased the fellow at Classe' but he was quite concerned with the safety of using anything other than the Littelfuse fuse because of the extensively described measurements in the data sheet to which you are referring. I plan on forwarding the data sheet for the fuse in question to both Synergistic and Hifi Tuning. I agree that the response should be interesting. For anyone interested, the fuse is a 215 series 012 Littelfuse...12 amp slo blo 5x 22mm.
+1 to Metralla's comment.

Vance, I'm not certain that the Classe person you spoke to was giving you a precise answer. Breaking capacity (also referred to as "interrupting rating") has nothing to do with the likelihood that inrush current at turn-on will cause unnecessary fuse blows. Or, at least, there is no direct relation between the two.

Breaking capacity refers to the maximum amount of current occurring under fault conditions, when the fuse SHOULD blow, that the fuse can deal with without an explosion or other safety hazard occurring. That rating will be far greater than the current rating of the fuse.

The parameter that is most relevant to withstanding inrush current without blowing unnecessarily is what is called the "nominal melting" point of the fuse, which is usually specified as (amps squared) x (seconds).

Datasheets at the Littelfuse site provide very comprehensive technical data on their fuses. You might want to look up the specs for the particular fuse that is in your amplifier, and ask the manufacturer of the upgraded fuse you are considering if they can provide you with the nominal melting spec for their fuse (as well as its breaking capacity, which as I said is relevant to safety). Their response should be interesting.

Regards,
-- Al
Tbg,

The 2300 and the rest of the new line have received universally stellar reviews and are actually innovative in their design. It's quite possible that Hifi Tuning or Synergistic may one day create an upgrade of this type of fuse. They are continually expanding their selection.
05-23-13: Vhiner writes:
an outfit called "Littlefuse. "
Forgive me, but the company is called Littelfuse. I believe they are one of the largest manufacturers of fuses in the world. They have an extremely broad inventory of fuses.

Regards,
Houston...we have a problem. I was just told by the person in charge of tech support at Classe that he believes only one or two manufacturers inthe workd mae a fuse with the specs required by the CA-2300. He said it wasn't enough to just get a 12 amp small, slow blow fuse....that it had to be particular type of "breaking capacity." He said he was only aware of one manufacturer of this type of fuse: an outfit called "Littlefuse. " He predicted that I'd regularly blow my amps' fuse unless it were able to handle the amplifier's massive current intake. When the 2300 is fired up, it is known to dim house lights because of the rush of current. Think I may sit this round out...unless someone has tried this on their own 2300.
"lol...Mapman, ah c'mon brother, were all mental someway or another :P"

You got that right...brother (pythons flexing...)!
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Mental, I understand but I actually participated in a comparison of two Home Depot cheater plugs ( 3 to 2 ac converters). One had been zapped on the Tesla coil and one not. It took but a few notes of everyone to say the zapped one was clearly superior.

Tesla was a genius and is the reason we have alternating current.

If the circuit design of your components allows it, cheater plugs on all but the linestage are an inexpensive and effective tweak. Of course, SR's tweak of the cheaters costs a good deal more as it is labor intensive and the coils wear out.

I really don't know what an audio guru is but I know fuses sound different if put in one way rather than the other. That tweak costs you nothing. : )
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Mental, I think that the use of the Tesla coil on the SR Quantum fuses is a crucial.
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Vhiner, at some point I would strongly suggest that you get some to the WA Quantum little fuse Chips to put on the center of the SR fuses. Also try the fuse both ways and use the best sounding direction.

SR claims their fuses are not directional but they are directional.
Tbg, I had just learned the 12.5 was available...but the Time Lag terminology was throwing me off, Rodman99999.

Many thanks to both of you! This is great news.

I'll post the results of adding the Synergistic fuse once I install it and burn it in.
AND just in case; Slo-Blo is synonymous with Time Lag, as can be seen on this Littelfuse data sheet: (http://www.mouser.com/ProductDetail/Littelfuse/0218010HXP/?qs=sGAEpiMZZMvFDy2ynfLiNS%252bPLgNldHoz4YtqwB9TwGI%3d)
Tbg,

That's good advice, but I remain a bit skeptical about sales people's expertise in this rather small niche of audiophilia. If anyone owns the new range of Classe amps and has installed a fuse upgrade, I'd love to hear about it. Classe has always discouraged fuse upgrades for reasons I have never fully understood.
Vhiner, I would call the Cable Company which sells all of the fuses. They should be able to give you this information. I assume this is just a 12A slow blow fuse, but I have never seen that value.
I just replaced my Classe' 2200 with a CA-2300. I was using a Hifi Supreme in the 2200 to excellent effect, but the 2300 has a completely different topology and requires the following fuse type:

IEC time lag, high breaking capacity 12A 250V

I cannot find this type listed among the Supremes' offerings, nor from Synergistic Research. Does any audiophile company make an upgraded fuse to replace this? Any suggestions welcome.
Hifi Supreme Tuning Fuse replacing main power fuse in integrated ARS Sonum-Filarmonia 30 watt E34L tube amp. Improved separation, more realistic all 'round. Not dramatic, but noticeable.
In response to Lacee's question, yes I do think the sonic signature of the fuse should be in synergy with each component. It is unfortunate, but like power cord comparisons a few years ago, people were saying this brand of cord is superior to that brand. As most of us know now, a power cord that sounds excellent on one component may not be very good on another component.
Same with fuses, in my limited experience. I have not tried the Audio Magic liquid fuse, but I have recently played with Hi Fi Tuning Gold and Supreme, Furutech, AMR, Synergistic, and one by Create, which has one end Gold plated and the other end Rhodium plated. So far, I am not much impressed with the Synergistic or the Create.
My opinion at this point is similar to Agisthos; fuses color the sound and are a hassle. I like the idea of a circuit breaker, which many manufacturers have chosen to use instead of a fuse. But don't go changing your fuses to circuit breakers right away...that's not what I am suggesting, unless you are really into it. And I do not suggest putting a metal slug in place of the fuse, as Agisthos and some others are doing. But that is up to you.
Sorry not to be definite here, but I can't be.
And the "Chips" ? I tried those on output transformers, and I must say the sound improvement is quite good. I have no idea how or why they work!
Yes I think you are right Norm. Even when I don't think the fuse is directional, I still put it with writing as the direction due to my audiophile OCD tendancies.
But with the SR when direction was changed I could hear it easily. I would not say it was vastly better, but it was certainly a different sonic presentation.

This was quite a change to my previous fuse direction swapping attempts, where I was straining to hear any difference.
Agisthos, I think SR hoped they would not be directional. So far I have always found the direction of the printing on the sticker on them goes against the direction where they sound best.
Agisthos, I think SR hoped they would not be directional. So far I have always found the direction of the printing on the sticker on them goes agains the direction where they sound best.
I also think the SR fuses are the best. And they are definately directional, unlike some of the other fuses where I could not tell a difference by reversing them.
I have had the AMR, Audio Magic Liquid and now SR fuses. In my opinion the best fuse was....... no fuse.

For DAC's, pre-amps and optical players you are better off jumping the fuse, always. I have never had to replace a blown fuse in low voltage equipment like this, so will run the risk.

Amplifiers is another story. I'm not game enough to go there, even with the electrical box having breaker switches. But once you realise how much a fuse can color the sound of your amp, it does gets tempting.

No fuse is just better. Imagine how bad UK audiophiles have it, as well as the components, they also have fuses in each AC connector of the main cables.
Byron J Cunningham,esquire,

That was an awesome and hilarious posting, especially the mittens part.

Well done and thank you,
Tim
Make that, "definitely." Sure would be nice if this site would let one edit one's posts!
Mr K- Kinda what I thought. Those markings are simply a logo. Most definately not a schematic. Happy listening!