SR black fuse orientation

[IceOgre]

Quick question. I was gifted an sr black fuse and am trying to determine he correct orientation to install the fuse.

From the SR website... “Yes, fuses are directional.  Electricity should flow from the left to the right when you view the fuse.  If you do not know the direction of flow you should listen to the fuse inserted in both directions.  One direction will sound more detailed.  This is the correct way.”

I think the flow if electricity across the fuse would be from the front of the amp to the rear. Is that correct?

Thanks,

[Paul Birkeland]

AC current flows in both directions... so now you know more than the the fuse manufacturer?

[mcandmar]

lol

[Chris65]

AC current flows in both directions... so now you know more than the the fuse manufacturer?

[Doc B.]

Electricity should flow from the left to the right when you view the fuse.

In many Middle eastern countries it flows from right to left. In China it used to flow from top to bottom.

[IceOgre]

Knew I would get blasted here. But educate me. Electricity comes in though the positive “hot terminal” correct? I know there is feedback from the circuit back to “the grid in my
House”. But in general most of the electricity/energy consumed by the amp is driving the headphone. Am I wrong? If there are demanding peaks in the music anything you can due to lower impedance of that electrical flow would help dynamic peaks? That being said... most of the electricity across the fuse is going one direction and transferring energy into air movement correct? I am not an engineer but rather a cfo. Be gentle.

[Paul Joppa]

Knew I would get blasted here. But educate me. Electricity comes in though the positive “hot terminal” correct? I know there is feedback from the circuit back to “the grid in my
House”. But in general most of the electricity/energy consumed by the amp is driving the headphone. Am I wrong? If there are demanding peaks in the music anything you can due to lower impedance of that electrical flow would help dynamic peaks? That being said... most of the electricity across the fuse is going one direction and transferring energy into air movement correct? I am not an engineer but rather a cfo. Be gentle.

The hot terminal is not "positive"; it has an alternating voltage that goes positive to negative and then reverses, 60 times a second.

Only a tiny fraction of the energy consumed is dissipated as signal in the headphone. The other 99.9% is dissipated as heat by the amp's tubes, resistors, power transformer, etc.

Dynamic audio peaks are extracted from the power supply capacitors. To a first approximation, Class A circuits such as the Crack, all SETs, etc. do not draw more from the power line during audio peaks.

So no, the current through the fuse does not go in one direction, and less than 0.1% goes into the headphones.

Incidentally, the headphones themselves are not at all efficient, so only a tiny fraction of the few milliwatts they do get goes into actual air movement.

[Paul Birkeland]

To a first approximation, Class A circuits such as the Crack, all SETs, etc. do not draw more from the power line during audio peaks.

Except for those pesky power grid tubes! (not at all relevant to the discussion)

[IceOgre]

Ahh understood. Thanks!

[Doc B.]

The fundamental point is as PB and PJ said - we are talking about alternating current. Anyway you cut it - electrons actually flowing thru the wire, SRs notion that the electrons are like the balls in a Newton's cradle just transferring energy from one electron to the next, "source and sink" energy models - the current is alternating. Unidirectional flow stuff happens after the rectifiers, regardless of whether you think electrons go from minus to plus or the current goes from plus to minus.

So when you throw the on switch, yeah, the current flows. But it flows back and forth through the fuse, not just one direction. The idea behind a fuse is that it creates a bottleneck that will heat up and, due to its increasing resistance, blow if the current is too high. It's supposed to do that.

The guy who sells fuses tells you the most significant component upgrade in your system is the fuse.
The guy who sells cables tells you the most significant component upgrade in your system is the cables.
And - not to pretend that I'm any different - the guy who sells everything tells you the most significant component upgrade in your system is, well, everything.

[IceOgre]

Thanks for the reply. Either way the Bottlehead kits are a ton of fun to build and to my ears sound better than most everything off the shelf. Whether that is a biased opinion or not I do not know. There is an emotional attachment to something you build with you own hands. They are also a great platform to build upon. This was not my first build and will not be my last. Thanks again explanation.

[kgoss]

You said the fuse was a gift so give it a try. Listen to it, flip it around, and see if you hear any improvement either way. See if you hear any improvement over the stock fuse too.  Please report back and let us know what you find. Personally I have never tried a botique fuse but this is the perfect opportunity to form your own opinion.

[Kitchener]

I would just like to add that for an certified ignoramus, me, this has been an educational read!
-I'd attach my Certificate of Ignorance from the Norwegian Institute of Ignorance, but they didn't know how to post it...

[Karl5150]

This thread has the perfect mix of information and levity. Reply #9, last paragraph = truth