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
128x128davidpritchard
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.
Bicycle_man

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.