Iso Clean Fuses

I just installed the Isoclean fuses in my Marantz SA-11S1 SaCd player. This player has 5 fuses inside. Turned it on and boy did it sound bad. The worst tweek I have ever tried. The highs were gone. In fact the over all volume was reduced! My heart sank. Faintly remembering the info sheet says these fuses have a direction to them, I had hope. Out comes the player from the stand. Fuses pointed in the other direction, now towards tha front of the player. Back in the stand, all connections remade. When i turned off the amp I left the volume at the same level. Power on. Hurray! SET magic sound restored. The crystal clear mids are there and the delicate highs have returned.
These fuses are supposed to be placed following the direction of current. I do not know if I have each circuit fused correctly as I do not have a diagram of the current flow. But in the Marantz the fuse arrow sounds better pointing to the front versus all pointing towards the rear.
So if you try an Isoclean fuse, try it in both directions before deciding if it helps or not.
David Pritchard
Thanks for the reminder. I should check and experiment with the other direction now installed in my amp. Was it a noticeable difference over the stock?

In my amp, an Art Audio Px-25 the improvement was immediate and obvious. Without going into audio babble-it just sounded better.
David Pritchard
Directionality in a fuse makes me wonder if it has diode-like properties. Otherwise, how could you explain directionality? Does it have shielding that is grounded only on one side like interconnect that thus makes it "directional." If so, I doubt that the length is enough to pick up emi or rfi.

bicycle_man, there is directionality to any metal conductor.
I love em.... a definite improvement, and not much money. I got mine from VHAudio, from Chris, great service.
and yes, they are most definitely directional.
I have used both Hifi tuning and IsocleansÂ… Yes they are BOTH directional even if the argrument is made that AC(alternating current) cannot be effected by a single direction, I don't know. However after trying Isocleans they are very open, transparent and smooth, good top end extension, and solid bass when in the correct direction of course..

The weirder of the 2 is the Hifi tunings as they at first exhibited a bit of a constricted sound and slightly aenimic thinner presentation. I tried the other direction and they were a little better, but these took a solid 20 or 30 hours before true evaluation showed improvements. They definitely also sound better in one direction than the other, and do sound as good or better in some equipment than the Isocleans once opened up.
That is a good reminder about the HiFi tuning fuses- that they need a break in time . I believe your explaination about needing a break in explains the varried experiences reported on the web concerning the HiFi fuses.
David Pritchard
And just what IS the current flow direction in an AC circuit?
Back and forth 60 times a second in power supply circuits and back and forth from 20 to 20000 times a second in speaker wires. So directionality, even if it exists in wire, makes no difference.

Bob P.
Do any high-end manufacturers equip their amps, pre-amps, tuners, or cd players with these fuses? I would be interested to hear what an actual professional electronics designer for a high-end audio manufacturer has to say about these fuses. I am not interested in what a marketing company for the fuses or for a high-end manufacturer has to say. Spare me the reviews from them; they just want to sell a product. I am talking about a real electronics engineer who designs amps, etc.

I understand the reported observations from audiophiles. No one seems to understand what is going on, nor can they explain it technically -- just get a bunch of superlatives and recommendations for inserting it one way or another because there is directionality to any metal conductor.

I don't think the conductivity of metal is as directional as that of doped silicon with a voltage drop across it. By "directionality" I mean impedance is more or less with current flowing in one direction than the other through the metal. Not the mere fact that current flows one a specific direction. Maybe at radio or microwave frequencies there is directionality of electrical conduction -- perhaps due to the molecular grain. I don't know; I am not a radio or microwave frequency electronics designer. However, even 20kHz is not high frequency by any means.

I know for a fact of about 3 manufactures you can call and they will offer them in the equipment for a small upgrade cost, also that do recommend the better fuses as they do sound much better... And 2 of them are huge names in the business, but they simply don't try to push a product based on a small piece of metal as you say for exactly that point. They also believe they can improve the sonics having them in all spots on the board not just the primary fuse in that you see on the back of your unit.

Think about it for one second, do you not believe that the one small cheap fuse with a tin wire thats like the thickness of a hair on your head is not causing a small current drop directly feeding the primary on your transformer? So realistically a 20 gauge generic power cable on your DVD or receiver is good enough over the 14 gauge solid copper wire in your wall feeding it to that point?

The direction I cannot specifically explain, however it really depends on the leg the fuse is put on inside the equipment, seems that its normally on the HOT side, not the Neutral side which is tied to ground, so your 2 major AC lines which are hot and neutral back to your breaker box are in fact 2 different legs of an electrical system.

So I would assume the only reason somehow direction is effected is its just better in some equipment depending on how the neutral and hot are ultimately run into that component, some gear is actually wired out of "Phase" and some have Phase switches on remotes and on the faceplate sometimes just for this reason. Again who cares, if it works, yes I will say that a better fuse is in fact a better fuse, the cheap ones vibrate like crazy, have ridiculous hair like thin elements, and yes the isocleans and hifi tunings are quite a bit more substantial.

This is nothing new, for years CAR audio DC circuits have been using MONSTER sized fuses, big huge Gold plates inside the fuse element for complete current conductivity.. These fuses are of course much more amp rated than home audio gear, but take a look at the big battery fuses etc, and see that they replace the little plastic 50 cent standard car type fuses as well for huge amps and current drawing devices for competions in cars, realistically its just to get the best current without much voltage drop possible if the transformers demand it.
Good point about the thin, tin wire construction of a cheap fuse. However, fuses are rated for current flow. If the rating is exceeded, the fuse blows. I think manufacturers specify the current rating of the fuse based on the demands of the equipment. I would also think that a small voltage drop across the fuse due to its resistance is far less than the fluctuations inherent in our ac power, and that a well designed power supply will easily handle any voltage drop across a fuse. I would dare say that any voltage drop across a fuse would be considered negligible compared to the ac line voltage.

The copper wire inside my 3 amp slo-blow fuse for my 35 w/ch amp looks pretty good. It doesn't look like tin at all. And, it is actually not hair-diameter thin.

As for your power cord argument, for a dvd player, or a receiver, yes I do think that 20g zip cord is more than adequate. Is it really 20g? I thought zip cord was more like 14g. Anyway the crap that comes with those machines is more than adequate as they don't draw much current. If the wire did not substantially exceed the current demands, the manufacturers would have a huge liability on their hands (oodles of law suits). For a high quality amplifier, however, you may hear an improvement in sound quality if you use a thicker cord with a filter near the amplifier. The filter for filtering out rf interference, of course. (I don't go for the skin effect arguments about power cords. There just isn't any at 60 hz.)

Let's not forget about phase since you brought it up. The phase switches that I have seen for audio equipment are not for the phase of the line voltage. It is for the phase of the output to the pre-amp in the case of a source, or to the amp in the case of a pre-amp. This switch is generally there because some music is recorded 180 degrees out of phase compared to usual recordings. In such a case, you will usually hear an improvement in the sound when you play the music back with the phase switched. Here, you most likely will hear an improvement when you turn the thing around (the phase in this instance, that is).

Perhaps I should try reversing the position of my amp's slo-blow fuse and see how it sounds. Interconnect wires and power cords with filter circuits installed in them typically sound better installed in one direction versus the other because of the shielding being grounded on one end. This is at the far end (i.e. the end where the power cord plugs into your amp, or the amp end where you have an interconnect from your pre-amp to your amp). This is because the wires and shielding pick up rf interference (acting as an antenna) so it makes sense to shunt this to ground at the end where it is being terminated. A fuse reversed sounding better? I would have to experience it for myself to believe it. Money back guarantee on the fuse? Even then the experiment is not worth it to me; the shipping costs that I would have to eat would make it a far too expensive experiment.
Well, if you don't trust the judgment of those who posted their experiences and not willing to spend the dough, then this is a non issue. Just be happy with what you have.
I would guess it depends on what you think too much money, but, bicycle man and others who doubt, I think you are missing out. It's quite an improvement for the money, and made a believer out of me. Why it's not done more often is beyond me, but it does seem like it's catching on. What would you normally pay for an improvement in your sound?

As far as the power cords, one quick demonstration would show you the way. If you couldn't hear the change, then you've saved yourself money.
What you consider, "too much" to pay, or what effort you're willing to expend for improved sound, is directly proportionate to you love for music and your ability to hear. Then, of course, there are always the Julian Hirsch disciples(everything sounds the same).
Oh, I think you can hear this change regardless of your abilities or loves....
It is a non-issue with me. I am very happy with my system thus far.

$39 is too much for me to pay for a fuse.

I read Isoclean's website information on their fuse. It contained implications, but no solid information about the how's and why's of their fuse and improvement in sound. They just basically said, "it improves the sound."

I simply reiterate, $39! It's just a fuse. Although I might add it is gold plated; that looks neat. And you can show it to your friends. Oh, and it says "audio grade" on it; you can point that out to your friends, as well.

But hey, if you are happy with your choice, good for you.

Bicycle man,

Put one in your amp and tranform your sound. The amp makes the most difference. I have one in my cdp and pre as well. I really hope you don't have a lot invested in your system , the musical enjoyment you are missing out on for a measly $39 bucks is quite entertaining.
Now leave Bicycle man alone, he seems quite content, as do we who have upgraded our fuses. Investment is a good point, if someone only spent $20 on zipcord for speaker cable, they'll think it total lunacy to spend $40 on a fuse.
Remember the saying, you can sometimes learn by observing those that can't.
I must point out that the "thin cheap" wire in a fuse is that way for a reason. A fuse is SUPPOSED to blow when its current rating is exceeded. You could put a big hefty gold-plated wire in a glass tube, but it wouldn't be a fuse. As for directional characteristics...remember that audiophilia is a religion, and all things are possible.
I put my 39 bucks towards things like cartridges, tubes, and coupling caps that I upgrade.

I prefer to put my money into my system where it makes sense from an engineering and electronics standpoint to do so. I do not listen to marketing rhetoric. I prefer to do the research myself and make an educated decision about the changes I make to my system.

Some of you have a derogatory tone in your response to my postings on this topic. Understandable -- you have plunked down a lot of money relative to the part you bought. It sounds to me, however, like the same arguments I heard from bozos who tweaked their systems with specially "treated" black plastic zip ties and used specially "treated" black plastic tweezers peddled for a lot of money by some audio "guru", or who bought the, again, specially "treated" Tice clock and refused to return it because their egos did not let them. Obviously their ears were better than mine; that is why I could not hear the difference. And, I did not love music as much as they did. Of course, don't forget that they did not actually listen to music; they only listened to the sound their system was making.
One thing I like about this hobby shows in this thread, everyone appoints themselves an expert, and objects to anything they don't have first hand knowledge of. Pretty amazing....
Bicycleman, I could shoot holes through your second paragraph and beginning of third, well,most of it. But you're resigned to your beliefs, so no need. I'm not remotely derogatory, unless you'd be a certain party who posts on here.
Like I said, if you were here, I could show you in the time it took to swap fuses the difference. I have no idea what system you have at home or what you are used to listening to/for, but, anyone can hear this difference, for the better I might add, not all changes are for the better in the long run. No rhetoric, no overpriced gizmo or snake oil. (I do serve great appetizers at my listening parties, though.) and lots of listening, and laughs...
Loosen up a bit, you're starting to sound like Julian Hirsh.
Well said.

I do not pretend for a moment to be an expert. I base my opinions on an education at, in my day, a top ten engineering school, experience in the audio retail industry, and my personal experience as an audiophile. I am knowledgeable, but not perfect.

I know that I have not tried the audio fuse. Of course, this is the big hole in my argument. If I had the means to do so for free, I might. However, my argument is that it is absurdly priced, and that it has no technological basis behind it.

In my system I can clearly hear the difference in tubes, capacitors, cables, and power line conditioners, among other things. I would make a gentleman's bet that the fuse I put in it would not make a difference. I would do that in any system because it has no basis in engineering principles. (I would also bet real money on it, if my opponent required it.) Of course I understand that the argument is that high end audio and engineering are at odds with each other. I hold that that need not be. I believe that sound engineering principles, if the designer were to pay attention to the minutiae, would coincide with great sound as far as an audiophile is concerned. That is the basis upon which I have built my system, and upon which I modify my amps.

Having worked in the industry, I witnessed a lot of snake oil being marketed. This was especially true of accessories where there is the highest profit margin. I am very skeptical of accessories and tweaks. Forty dollars is an exorbitant price too pay for something that most likely costs pennies to make. It seems that what you are paying for is perceived value and mystique. That is the only conclusion that I can draw when no one, including the sellers, can offer some technical principles for the supposed improvements on which this product is based.

I understand your Julian Hirsch comment. I am open to trying new ideas. However, I still maintain that there is a rational and scientific explanation to improvements in the music coming from the speakers. So far, there have been none concerning these fuses.
Bicycle_man ... "Audiophile" fuses are not over the top. We still have cryo-treated audiophile fuses, installed in a preferred direction, and probably more after that!
Hi Bicycleman, you have every reason to be skeptical, based on what you currently believe and on your past observations.
So tell us, what amp are you using now? and what value and type is the main fuse?

And I'll tell you a quick story:
A friend and I had swapped amps for a while, and while he had mine, he replaced the main fuse with an isoclean. When I got it home, I thought, sounds okay, I like his amp better. After he told me what he had done, I thought that's nice, but no great shakes at all. But then I got down and inspected it, saw the directionality arrow on it, and decided to place it the other way. Oila! The difference was amazing! It was gorgeous. Now, this is certainly better than tube rolling, because in the fuse case you either have greatness or you don't, not mere differences.
Surely a man of science can relate.
How many of you nay-sayers have actually tried the Hi-Fi Tuning, IsoClean or Furutech fuses again? Surely you're not simply offering unsubstantiated, empty opinions? I've upgraded every power supply and signal path in my audio chain with OS-CONs, FREDs, bulk foil resistors, polystyrene/polypropylene caps. Selected cables, interconnects and NOS tubes, with care, towards the most transparency possible, and done the same for many aurally pleased clients over the years. When I tried the Hi-Fi Tuning fuses in my Cary monoblock power amps, there was an obvious and quite audible improvement. The technology to actually observe electrons, and their behavior within the crystaline structures of various metals, must have escaped the professors at Case Institute. I don't remember that being presented during any of our courses.
Neodymium magnets, circumference treated with AVM, same area then electro insulated, circumference area mumetal shielded. Yet to determine influence of north or south pole of magnet on signal flow and resulting sound. Tom.
Rodman99999... "unsubstantiated, empty opinions". That's a good description of the subjective endorsements put forth by fuse believers.
I'm not a "believer", I'm a listener. I've made a living with my ears for over 30 years. We(Those of us with ears and resolving systems, that have ACTUALLY tried the fuses) have the experience of actually hearing the differences that these fuses make. On what exactly are your opinions based? The founder of Linn(Ivor Tiefenbrun) said it best: "If you haven't heard it, you have no opinion!" One of my favorite quotes. The rest of you can have all the vapid, opinionated "last words" you want. Seems you can't help yourselves.
Rodman99999...Hearing is subjective and like the other senses, easily fooled.
yet not in this case...calm listening will easily prevail.
I started this thread and its purpose is to remind those that have bought fuses that state they have a direction to them, to try the fuse in both directions. The direction of the fuse made a difference in my system. If people want to debate the possibility of directional fuses please start a new thread. I hope Bicycle_man and Elartford will not post any more to this thread.
David Pritchard
Nice. Okay, David, one quick question which I should have asked from the nice folks I bought my fuses from, it's obviously easy (for us) to tell which direction the fuse is suppose to go by hearing it, but if you were to go by arrow only, is there any way to know?
and be nice to bicycleman, I think he's gonna buck for one sooner or later, elartford, well, i think it spells e oldfart, and he's thinking like one...:)
David, there wasn't really any point in starting this thread then. For those who believe that direction makes a difference (or even that fuses make a difference) then no need to remind them. For those who do not believe that direction nor fuses make any difference there is no danger that they will buy one. So what was the point of the original post, if not to solicite opinions on a long past sterile subject?

respectfully, Bob p.
Those who resort to personal attacks thereby admit that their argument is weak.
Not I! I was only trying to be funny, totally tongue in cheek.
As I've been trying to get across, if we could get together, it would be a simple demonstration, and very decent respectful conversation, at least at my house. And if there were folks that didn't get it or nor think it be worth the change, then that would be very respectfully treated, with snacks, no less.
Why do you think people like Julian Hirsch finally got drowned out by the likes of J Gordon Holt or Harry Pearson? Because his way of thinking was finally discredited in so many ways. Look at how audio has changed.
I'm not calling anyone Julian, not anymore. But you owe it to yourself to go find out the facts.
And you're welcome to come over for a fun listen.


I replaced all my fuses in amp, pre and CD and it truly made a difference. These fuses are definitely directional, try playing Canon D and pay close attention to the high frequency in the right channel and reverse the fuse, you will notice reduced extension when reversed. But experiment you'll hear the difference, easy!