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Is it safe to use a higher amperage rating fuse?

Today was my 2nd attempt at trying out Synergistic Research fuses.  About 3 years ago when I had separates, including mono block amps, I bought a set of Blue fuses.  One component had a mfg spec of 250mA and the retailer said go with 315mA.  My two mono block amps each had a 6.3A.  When I installed them one of them blew upon powering up.  The retailer said we should go up to the next rating.  I was a bit frustrated at the experience and didn't feel comfortable putting higher values in my expensive components.  I felt these expensive fuses should be made to tighter tolerances than the cheap BUSS fuses I had been using.  If I remember correctly, that was the actual argument that the dealer told me.  They are mfg to tighter tolerances so a 5A SR fuse was almost dead-on 5A while a cheap fuse may actually be 5.3A or whatever.  This also was a bit confusing at the time so I sent them all back.

Okay...3 years have passed and now I have a single integrated amp which has a 5A fuse.  Much less to invest in the upgrade so I ordered an Orange.  It came in today...installed....pressed power...on and off went the amp.  DAMN!!  I contacted the retailer and SR on the same email.  This was a different dealer from 3 years ago.  The retailer said I should go to the next value up.  I said no and and they are waiting for the tracking info of my return shipment.

I did a quick search of my question before posting and saw a thread about the Red fuses and someone said they had to do the exact same thing.  Is everyone putting higher rated fuses in their gear that is worth thousands of dollars?  Is there no risk in this?  I admit that I don't know what could actually happen from that.  It seems that other things could burn up if a higher amperage fuse is in place.  I am compelled to simply stick to the mfg specs for something that I don't understand because I don't want to create problems just from a simple tweak.

Should I let them ship me a 6.3A or just be done with this?
dhite71
dhite71 OP
289 posts
 
@pauly no issues otherwise(knock knock).  This was simply a tweak/experiment.  The stock 5A fuse works as expected.
georgehifi's avatar
georgehifi
10,312 posts
 


dhite71 OP
This kind of dangerous advise below is total lunacy and could only come from a "snake oil fusers" mouths, which all have no concept of electronics whatsoever.

Me being one of the few actually has common sense, when mine blew I didn’t go up one baby step I doubled the damn thing. Why not? There are guys soldering wires straight across simply because it sounds better.


Cheers George
christian's avatar
Ag insider logo xs@2x
christian
78 posts
 
@pauly no issues otherwise(knock knock). This was simply a tweak/experiment. The stock 5A fuse works as expected.
Ah... I love happy endings! :-)
pauly
1,012 posts
 
@OP
Fuses are noisy. You can use a small value capacitor, 0.01 uF and smaller wired between live and ground to mitigate the noise. 
Note, if you wire the capacitor upstream from the fuse, you have to use a capacitor that is rated to be used on mains I.e. a class Y capacitor. https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/

Downstream from the fuse you can use a regular film capacitor.

I found a good quality film cap downstream from the fuse wired across live and ground sometimes produces an audible improvement in the sound. A Y cap upstream from the fuse not so much.

dletch2
455 posts
 
When I installed them one of them blew upon powering up.  The retailer said we should go up to the next rating.  I was a bit frustrated at the experience and didn't feel comfortable putting higher values in my expensive components.  I felt these expensive fuses should be made to tighter tolerances than the cheap BUSS fuses I had been using.  If I remember correctly, that was the actual argument that the dealer told me.



This is what is referred to as a lie. Obviously they are not manufactured to tighter tolerances, reasons already given.


So what are you left with:

  • Fast blow marked as slow blow?
  • Poor quality control?
  • Up-marking the fuse, i.e. taking a 3A fuse and rating it 5A.  Why would someone do that?  Well that will make the fuse run hotter and will increase the fuse resistance. Bad thing right? Nope, More resistance in the AC line, and the noise will always drop a bit. Noticeable? Probably not.  When the fuse gets hot, the resistance goes up a lot. Noticeable? ... who knows.  But .. but .. but .. thermal modulation!   Well you don't want thermal modulation for a speaker fuse in a speaker line. In a power line that will give you even more filtering.

Don't you wish the manufacturer had their products validated by a 3rd party lab?  ... like any product that fulfills a safety function should be!   Probably it is .... by the company that makes it for $0.10 ...
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