Fuse Direction for Pass Labs Amp and Preamp


I am going to re fuse my Pass X250.8 and XP-32 with Synergistic Research purple fuses in a couple of days. I was hoping to get advice on a rule of thumb for direction of the fuses. My instinct tells me to start by installing the fuse by the direction of the lettering on the fuses. I am thinking that the direction should be the lettering left to right with the beginning of the lettering facing out of the amp and the end of the lettering facing into the amp. Does this sound right?

128x128mitchb

@mitchb : I see you have drunk the fuser Kool Aid! How can you believe this nonsense that a small piece of wire - which does not carry a music signal - can somehow change the character of a component - and cost hundreds! Enlighten me!

Jason
How you feel about fuses now people felt about power cables 25 years ago. People in fact do hear a significant difference between stock fuses and high end fuses. Why a little wire makes such a dramatic difference I don’t know but it does. It has been proven by people’s experience. There are those who feel power products like cables and connectors don’t make a difference but they do. Not always positive I admit as everything is system dependent.

I can tell you that Lloyd Walker suggested that I try the fuse both ways in my Walker Motor Drive to see which direction I preferred.  He could hear a difference, but I could not.  I'd suggest that you follow Lloyd's advice and see if you have a preference..

My situation is that I am doing 4 components at the same time. Technically I should do one at a time and swap the fuse to hear which works best but I was hoping to just install the 4 fuses at the same time. Someone sent me a diagram in a different forum which shows which way the direction of the fuse should go. I will follow the diagram sent to me as a guide.

I am thinking that the direction should be the lettering left to right with the beginning of the lettering facing out of the amp and the end of the lettering facing into the amp. Does this sound right?

@mitchb 

Not unless the fuses are in a DC circuit, and somehow have better conductivity in one direction rather than the other!

What people hear when they swap fuse direction isn't the fuse having 'directional' properties! Its a combination of the fit of the fuse in its holder (resulting in a lower voltage drop across the fuseholder) and expectation bias. The former is measurable (and slight), the latter is not.

It is impossible for a fuse to have a directional property in an AC circuit! That would cause it to favor one half of the AC power waveform and not the other- this would cause the fuse to heat up, since in the non-favored direction its resistance would be higher. Ohm's Law dictates this.

This would cause the fuse to heat up and fail, possibly within seconds of operation.

This statement is false:

Why a little wire makes such a dramatic difference I don’t know but it does. It has been proven by people’s experience. There are those who feel power products like cables and connectors don’t make a difference but they do. Not always positive I admit as everything is system dependent.

You can measure voltage drops across power cords and that can affect power amps that draw a lot of current (IOW they obey Ohm's Law). But its quite incorrect to say that this aspect of fuses is 'proven'. Its clearly not; I explained why. Further, I presented the explanation of why its actually impossible.

There are a lot of myths in audio, for example the idea that a certain speaker or amplifier can sound favor a certain genre of music. These myths exist in a viral form and infect in a way not unlike actual viruses. Once you disabuse yourself of them, you'll find that you can make greater progress on the sound of your system.