[zuluwarrior0760]

bought some hifi tuning fuses and they say to place the top of the triangle
logo in the direction of the signal (even though it's AC, LOL)

I am assuming that the bottom of the fuse holder represents where power enters
and the top is where it exits.....

Can anyone confirm this?

Thanks

[Davey]

  Once you go down the rabbit hole............

Try them both ways and see which way sounds better.

Dave.

[SteveFord]

I have to ask: do they give any reason for mounting a fuse in one direction or another?

[Goosepond]

I've had some experience with this, and believe me it works. When putting in the fuse make sure you're standing on one foot (the left is better than the right for me but that's probably because I'm left-handed) and cough once. Try it! 

Gene

[zuluwarrior0760]

clever remarks but no answer to the question (which way does the current go in a magnepan 3.7 fuseblock)....

What possible benefit would there be for the manufacturer to say his fuses are directional if it's unmeasurable snakeoil   (he's already sold em).......

I tried them both ways and one sounds subtly more open but the difference isn't profound....., I just wanted to know if
anyone knew the direction so I could see if my ears were telling me opposite of actual best practice or no......

Here's more:
http://www.psaudio.com/vanilla/discussion/2619/the-fuse-direction-conspirathy-theory/p1

[Davey]

You answered your own question in your first post.  This is AC....the current goes both directions.
It's simply impossible to install these devices incorrectly.  It can't possibly matter.  If they tell you different they're just blowing smoke up your ass.

I don't doubt your ears are telling you something, but it's only because you have a preconceived notion to hear a difference.

However, the audible effects of these "fuses" are not the concern here.  The safety aspect and whether they actually open/protect at anywhere near their current rating is of much more concern.  A few users have noticed they don't appear to have much protective capability.  The problem is you can't really objectively bench test them to failure because they're too damn expensive.  Ingenious marketing. 

Cheers,

Dave.

[zuluwarrior0760]

Davey,

I could give a lot less than a crap what people think about the plausibility
of whether this matters, and you're right, I'm well aware that AC means
current runs both ways, but from a load standpoint, there is a supply end
and a load end........

I guess my last two phono cable manufacturers who suggested installing
their phono cables in the direction of the current per an arrow on the jacket
is also just trying to make fun of me..........

HiFi Tuning fuses are pretty well regarded in the Magnepan community
and if the manufacturer says it matters (they do) and they say it can be
measured (I have no idea whether it can) then the least I want to do
is install them in the manner prescribed whether it's smoke up my ass or not.....
because it doesn't cost me a red nickel to do so, which can't be said of any of the
other stupid snake oil I've bought over the years.......

I have given up on getting my original question answered.  Calling Magnepan Monday
to find out which end of the fuse is connected to the crossover and which end is connected
to the panels......

[kevin360]

If you're going to install slow-blow fuses in place of the stock fuses, save your money and improve the circuit by eliminating the fuses and their holders altogether. Those fuses will be as effective as jumpers - your drivers will protect them, instead of the other way 'round.

[Davey]

Davey,

I could give a lot less than a crap what people think about the plausibility
of whether this matters, and you're right, I'm well aware that AC means
current runs both ways, but from a load standpoint, there is a supply end
and a load end........

I guess my last two phono cable manufacturers who suggested installing
their phono cables in the direction of the current per an arrow on the jacket
is also just trying to make fun of me..........

HiFi Tuning fuses are pretty well regarded in the Magnepan community
and if the manufacturer says it matters (they do) and they say it can be
measured (I have no idea whether it can) then the least I want to do
is install them in the manner prescribed whether it's smoke up my ass or not.....
because it doesn't cost me a red nickel to do so, which can't be said of any of the
other stupid snake oil I've bought over the years.......

I have given up on getting my original question answered.  Calling Magnepan Monday
to find out which end of the fuse is connected to the crossover and which end is connected
to the panels......

You're attempting to make this more complicated than it is. 
There isn't any difference between the load and the supply......as far as the fuse is concerned.  Which direction you install that fuse is a complete non-issue.
You answered your original question....correctly.  Your instinct was exactly correct.  Why can't you believe that?

Interconnects are a completely different animal because some of those ARE directional because you have two conductors and differences of shield configuration and connector internal termination.

Cheers,

Dave.

[zuluwarrior0760]

This is what I was directed to........don't know whether to refute or accept......
so I'm just going to turn the damn thing in the direction they recommend
and relax.........knowing noone ripped me off (except for the cost of these fuses)

My understanding is, even these fuses have a break-in......
thus far the difference most noted to me is seperation of voices and maybe
a touch more air.......

Other than that, time will tell

http://www.ultrasystem.com/documents/WorldsLargestFsMsrmtReport.pdf

[Davey]

Yeah, I've seen that.  I'm not sure that testing is legitimate, but note that none of the scenarios are meaningful to usage in speaker leads.

I can certainly believe there is a measurable diode effect to fuses (in fact some of the fuse manufacturers have performed reputable testing) and that it might even be audible, but in this case it STILL won't make any difference which way you install the fuses.  Your program material is AC and even if it does contains some amount of asymmetry you couldn't determine a consistently correct orientation.

This is similar to the absolute polarity issue.  It can certainly be audible, but you'd need to evaluate every recording you have to determine if there's a correct setting and if so then always return to that setting the next play.  And that setting might change between different tracks on the same CD.    You can see what a horrible mess that turns in to. 

Also, as Kevin touched on, there is the discussion of whether fuses (of any type) provide reliable protection to ribbon drivers in Magnepans.  It's very easy to create a condition where the drivers protect the fuses. 

Cheers,

Dave.

[kevin360]

Also, as Kevin touched on, there is the discussion of whether fuses (of any type) provide reliable protection to ribbon drivers in Magnepans.  It's very easy to create a condition where the drivers protect the fuses.

Indeed, this is true for the ribbon and the stock fuse. Replace that with a fuse which takes orders of magnitude longer to open and I can't conceive of a condition under which the fuse will protect the ribbon. I guess it's just a feel-good device. I did away with mine a while back (after playing around with various fuse types, resistors and RF chokes). I don't have any of that stuff anymore - my connector plates are full of holes.

[Davey]

We don't know what the 3.7 tweeter crossover network looks like, but if it's similar to the 3.6, the best protection device that could be added is another series capacitor in the network to filter lower frequencies more effectively.  Those lower frequencies are what might create deflection issues for the tweeter element and heating issues for the tweeter fuse.
Ideally, the existing high-pass components (inductor and capacitor) would need to be adjusted also to provide similar phase performance for a third-order network.  (However, that would involve breaking into the speakers.)

I also don't like the 200uF bypass configuration that some have adopted.  (lower picture on this link.)

http://www.integracoustics.com/MUG/MUG/tweaks/mag3.6xover.html

That takes away some lower frequency protection from the tweeter driver.

Dave.