To Fuse or Not to Fuse... That is the question!

The following is so laughably incorrect, I don't know whether the poster was honestly communicating what they believe or if they were trolling. 

This is wrong. It is not open to debate (unless you have no clue how electricity works). Of course energy is transferred in both directions. That is why power supply ripple is NOT at 60Hz, it is at 120Hz (or 100Hz). Again, not remotely open to debate and easily confirmed. If there is 60Hz noise that is being injected directly into the signal, not from power supply ripple. 

Signed,  "Someone who actually does this for a living."


"You can ignore the current traveling in the direction away from the speakers, I.e., toward the wall, since that direction of current flow is not (rpt not) audible. The only direction that’s audible for any wire is the one toward the speakers. It is the speakers that ultimately produce the sound you hear. So, it’s the “quality” of the current traveling toward the speakers that is the issue. That’s why fuses sound better in one direction, worse in the other direction in AC circuits and DC circuits. As Old Blue Eyes sez, that’s life. "

This is really only partially true and from a certifications standpoint not usually true. The main purpose of an AC mains fuse is to protect the AC wire leading to the equipment so that it does not heat up and cause a fire. In theory any overheating inside an piece of equipment will be suitably contained by the enclosure. Where the case is metal and grounded, it can also provide protection from a live wire contacting the grounded case, which is neutral connected at the panel and will hence blow.


Almarg 9-26-2019
I just want to state a point of information: Posts that have been made by at least three different members appear to imply that the purpose of an AC mains fuse in a component is to provide protection against surges in the incoming AC. While it is possible that an AC mains fuse might do that under some circumstances, that is not its intended purpose. Its intended purpose is to blow if a fault within the component causes it to draw excessive AC current. Thereby preventing **additional** damage to the component that may otherwise occur, as well as preventing the possibility of the component overheating or even bursting into flames as a result of the excessive current being drawn. 

The other reason for a fuse is if the equipment has MOV based surge protection which will typically fail short, but technically that is covered by the my first case ... to protect the wire connected to the equipment.

roberttcan"The following is so laughably incorrect, I don't know whether the poster was honestly communicating what they believe or if they were trolling. This is wrong. It is not open to debate (unless you have no clue how electricity works). Of course energy is transferred in both directions."

No has has claimed, asserted, or argued otherwise perhaps you are confused, disoriented, or lack proper reading comprehension.

Excuse me?  That is EXACTLY what someone claimed. This is a direct quote from this thread. geoffkait specifically. Don't shoot me, I am just the messenger, not the comedian. It seems it is you that lacks reading comprehension or just wanted to look like the big man on the block, but were too lazy to do due diligence or perhaps you just don't understand the topic at hand similar to how goeffkait does not understand it.

The FUSE, no matter the direction of the current flow, impedes (or doesn't impede) the flow of electrons which impacts the flow of every electron at a macro level in the circuit. It doesn't matter whether the electrons are flowing into the left or right side of the fuse. The effect is the same with an AC signal ... it is a 2 port device.

If you truly believe the fuses are directional, then you should open up your electronics and start playing around with the direction of every resistor and non polarized capacitor too .... let me know how that goes.

Bye



geoffkait17,586 posts10-13-2019 7:51amibmjunkman
OK, I am totally confused. You guys saying you use these fuses in AC circuits?

From their web site:
A: 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 thought AC changed directions 60 times a second? 

>>>>>Thanks for bringing that up. Actually most audio fuses happen to be in AC circuits. It’s true current changes direction on the wire according to where the fuse is located. If the fuse is located where power comes into the CD player, preamp or amp or whatever it changes 60 times per second. But if the fuse is located in the speaker the current changes according to frequencies of the audio waveform. Thus the current at the fuse in the speaker changes 20 to 20,000 times per second - or more or less. If the fuse is in a DC circuit obviously current is unidirectional.

You can ignore the current traveling in the direction away from the speakers, I.e., toward the wall, since that direction of current flow is not (rpt not) audible. The only direction that’s audible for any wire is the one toward the speakers. It is the speakers that ultimately produce the sound you hear. So, it’s the “quality” of the current traveling toward the speakers that is the issue. That’s why fuses sound better in one direction, worse in the other direction in AC circuits and DC circuits. As Old Blue Eyes sez, that’s life.