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
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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....