We Need A Separate Forum for Fuses

Given the relative length of a fuse’s wire to that of a 5 yard speaker cable - let’s say 1:500 - I’d wager that a fuse would have 1/500th of the effect on the sound of your system than a cable can, assuming you believe cables can make any discernable difference.

Go figure!

geoffkait - last time I tested a fuse for resistance, I think the value on my meter was 0.000 ohms.

trelja - the fuses in a speaker are going to be operating with a valiable voltage depending on the volume, so they will, as I suggested in my post above, be skirting very close to their blow point at times and will therefore be prone to dissipating some heat, so I would expect some voltage drop and a notable difference in the sound - the increased heat and resistance will throttle the current available to the speaker and this is likely what you can hear.

However, the fuse in a power supply or on the supply rail of an amplifier is not exposed to such variation - it’s handling a DC supply, rather than an AC signal. Let's leave fuses in your AC 120v / 220v supply aside for now.

There is a big difference between the behavior of supply current and signal current and fuses will behave differently with each.

I thought your tweeter story was fascinating, but I would doubt whether the expensive fuse would sound better than the regular fuse - however I can see why no fuse would sound the best!

Seriously though, if there was a resistance in your fuse, there would be a voltage drop accross it, which would adversly affect your equipment and comprimise it’s design.

Fuses are designed to only dissipate heat (and therefore present a resistance) very close to the point of failure. If your fuse is presenting a resistance it must be dissipating heat to some extent, which will lower the voltage accross it, which will be measurable with a meter (however good). If this was the case, then I would suggest using a slightly higher rate fuse e.g. swapping a 2.5amp for a 3amp

Either way, any fuse operating that close to it’s limit would blow with the least provocation; i.e. powering up the amplifier would blow it.

fuses are NOT supposed to be affecting the audio signal

.and if the are, you have a problem someplace.

"I am certain that for this kind of money a completely new and well designed power supply could be installed in the users problematic equipment."

Right on!

Just because is costs 30 grand, doesn’t always mean it’s any good

Shadorne - your comment above is why I chose to leave AC power fuses to one side. The problem here is that fuses are being discussed in three different contexts - I think you hinted at that above:

1. DC Power Fuses
2. AC Power Fuses
3. AC Signal fuses

All audio signals are AC incitentally. Power fuses should behave the same regardless of whether the source is AC or DC, because AC power is a consistant wave i.e. 50 or 60HZ at 120 or 220v. If swapping fuses here makes a difference here, you have a problem.

AC signals vary greatly in voltage and available current, depending on what they are driving i.e. the impedence they are presented with. This is where fuses in the signal path will create all sorts of different results as the signal current approaches and recedes from the blow-point.

I’d also urge folks here to be very careful changing power fuses. They are there for a reason and the recommended fuse rating should always be used regardless of cost or what the manufacturer claims makes the fuse special.

A better term would probably be indirectional, as there is no directionality.

Either way geoffkait, can you elaborate, as I fail to see how a fuse carrying an AC current can be directional.

Thx

geoffkait - how can a fuse in an AC circuit be directional? AC by it’s nature is non-directional. Please elaborate. Thx

geoffkait - the notion of diretionality means to favour one direction over the other. If the current travels in two directions, there is no favoured direction, therefore directionality becomes irellevant, hence my use of the term 'indirectional'.

My question to you was how can a fuse demonstrate directionality i.e. to favour a particular direction when the current travels in both. Switching the fuse direction doesn't answer it as if the fuse was directional, there would always be one direction that would suffer - so you're just swapping the problem around.

And I would also go on to say that anyone who suggests that no fuse is best when fuses are put there to protect people from electric shock and potential death needs to think hard about their motivation to make such statements.