Hi-Fi Tunig Fuses & Parasound A21

6.3A fuse ?

I have also found that the sound changes with the direction of the fuse. In one way it is relaxed with a very clear mid-range specially the voice with a little loose bass. The reverse direction produces a very fast, punchy sound with a controlled bass but it had a tad hazy mid-range specially the voice.. I wanted to get both but it is not possible at least with the current stock fuse.

This is not caused by reversal of the fuse but how it makes a connection. Quite often by reversing the fuse you get a better connection because the fuse sits better in its holder and thus there is a lower voltage drop across it.

IOW its the connection, not that its reversed. If the only way to get the fuse in the holder is by removing the fuse cap, you might not have much option but to reverse the fuse to see if the contact is better.

atmasphere
5,020 posts
11-16-2016 10:59am
I have also found that the sound changes with the direction of the fuse. In one way it is relaxed with a very clear mid-range specially the voice with a little loose bass. The reverse direction produces a very fast, punchy sound with a controlled bass but it had a tad hazy mid-range specially the voice.. I wanted to get both but it is not possible at least with the current stock fuse. This is not caused by reversal of the fuse but how it makes a connection. Quite often by reversing the fuse you get a better connection because the fuse sits better in its holder and thus there is a lower voltage drop across it.

IOW its the connection, not that its reversed. If the only way to get the fuse in the holder is by removing the fuse cap, you might not have much option but to reverse the fuse to see if the contact is better."

Sorry, Charlie, nice try. But that’s simply not true. When the fuse itself, without the fuse holder even involved, there is a bigger voltage drop for one direction over the other. Hel-loo! Besides, careful and thorough testing reveals that the direction of the FUSE is actually more obvious in listening tests than any directionality the contacts of the fuse holder may or may not produce. More importantly, the direction of all wire, not only the wire on fuses, is directional. You can say that it’s the contact until you’re blue in the face, it’s no skin off my nose. This is an excellent example of the Backfire Effect, the more someone’s belief is challenged the more he believes he must actually be right. Common in this hobby, I might add.

From the silent majority, we have a 180 (or is it 360?) degree view on the subject of fuse directionality.

atmosphere = +100

geoffkait = -100

Atmasphere is certainly not alone in his contention, which btw he has indicated in past threads he has confirmed via measurements. See my post dated 10-28-2016 on page 58 of the long-running thread https://forum.audiogon.com/discussions/synergistic-red-fuse?page=58, in which I cite relevant comments not only by Atmasphere but by three other highly experienced designers of well-regarded audio electronics.

I also state in that post, as a highly experienced electronics designer myself (in the defense electronics field), that "claims of directionality in fuses [are] fundamentally irreconcilable with any reasonable understanding of how electronic circuits work." While also completely recognizing, of course, "that an understanding of how electronic circuits work can’t explain or predict everything about what we hear or don’t hear from our systems."

Finally, even if contentions that fuses inherently have audibly significant directional characteristics are correct (which they are not), it would stand to reason that the effects of any such directional differences would be completely swamped by the much greater directional differences that would presumably be caused by the vastly greater lengths of the associated wiring. In the case of AC mains fuses that would include the wiring in the primary of the power transformer, the internal AC wiring of the component, the wiring in the power cord, and presumably even the AC wiring inside and outside of the house.

Geoff (and others, most of whom are also not electronics designers) will of course disagree with all of this, but that’s how I (and the four well-regarded designers quoted in the post I referenced) all see it.

Regards,
-- Al