Replacing fuse


Would replacing an 6.3A SLO BLO fuse with an 8 SLO BLO fuse be ok? Thanks for any information.
john421
While many here have and would disagree with me, aside from the potential warranty issue I wouldn’t worry too much about substituting an audiophile-oriented fuse having a current rating 27% higher than the original. For two reasons:

1) There have been numerous reports here in recent years of various audiophile-oriented fuses blowing when they shouldn’t have. From at least 8 different members that I can recall in the case of SR fuse threads alone. Which suggests to me that the unspecified melting points of many of these fuses may be significantly lower than their current ratings would suggest. (Melting point is commonly specified by major manufacturers such as Littelfuse and Cooper Bussmann in terms of amperes-squared x seconds, but I don’t recall ever seeing such a spec being provided by a manufacturer of audiophile-oriented fuses).

I don’t recall previously seeing reports about false blows in the specific case of HiFi Tuning fuses, but as a member for whom I have great respect I certainly have zero doubt as to the veracity of Analogluvr’s statement.

2) Another reason for my relative lack of concern about the 27% rating increase is that it’s not an exact science. I would expect that the designer analyzes and/or measures the current draw of the component under worst case operating conditions, and also the magnitude and duration of the "inrush" current surge that occurs at turn-on, and chooses the current rating and melting point of the fuse by applying what seems to him or her to be a comfortable margin relative to those numbers. Another designer might very conceivably choose a somewhat different margin.

IMO. As I said, many others here have and would make reasonable arguments to the contrary.

Regards,
-- Al
I guess my concern is that the OP is clearly a neophyte to fuses and uncomfortable with the whole process, so the safest advice is to stick with the rated fuse

My own experience with SR fuses is that they do tend to blow on start up so I as a rule go "one size up" which would be the 8A for 6.3A, but I do this eyes open and well aware of the risks I am taking.

I think to recommend this for someone who is making a decision based on stock on hand and saving a few $ is the wrong advice. Most likely you'll not have any issues agreed but why risk it?

There are of course those who swear by bypassing the fuses completely ...
I'm some what knowledgeable about fuses but no I'm not an electrician or pretend to be an expert on audio equipment.Guess I'm curious about the fuse tweak and wanted to experiment without wasting money doing so.Some say they work, others say no.Some say a step lower or higher in value is ok so I was looking at other options and opinions.
Post removed 

I heartedly agree with almarg's position.  In the big scheme of things, 1.7A difference is not a whole lot when you are looking at a 6.3A reference point.   And it really varies depending on manufacturer.  A 6.3A fuse is relatively equal to 756 watts of energy.  Bumping this up to 960 watts with an 8A fuse is likely not going to make much difference of where the fuse breaks/melts, especially since this is probably going into an amplifier which will use a lot of current anyways.  I would say that using a 10A or more fuse may start to border on the "too much" scale.  The bigger amps that use 10A  or 15A will have a lot more power supply and circuits to spread the energy around before it hits the "too much" threshold.

I have seen some manufacturers that are right on the edge of what the amp will use (watts plus overhead/waste) and others that are 2-4 amps above what the electronic device is scoped for.

Generally speaking, a higher amp fuse is a thicker wire with less resistance.  It will allow more current and faster current through to the device and the result can be improved dynamics and punch/power in the sound.  There is a point where it doesn't make much difference.

john421 likely purchased one of the clearance fuses from Parts Connexion.  These are probably either Hi-Fi Tuning Gold or Hi-Fi Tuning Silverstar, selling for around $15 or so.