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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
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 ...
hobo1452's avatar
hobo1452
85 posts
 
Of all the snake oil  BS out there in audiophile land, these so called audiophile fuses stink the worst. And as far as the rated fuse goes, NEVER, repeat NEVER replace the blown fuse with a higher rated fuse unless you just really don't care about your audio gear. Design engineers specify a fuse that will handle normal AND peak demand loads for a safe period without blowing. That fuse blew for a reason. It might, maybe, possibly,  have been a defective fuse. The chances of you getting two defective fuses in a row is miniscule, so if the replacement fuse blows, you have an equipment problem. If you like spending money, go ahead and put a higher amp fuse in. The repair shop will love you for it.
speakermaster
738 posts
 
I would not put a higher value fuse in your gear try to find a vintage fuse supplier they were made a different and more robust way and they sound better too.
gs5556
1,235 posts
 
If fuses are not manufactured correctly they will trip when they’re not supposed to. It’s no surprise the boutique fuse salesmen do not provide time current curves or melting energy. Going up in fuse sizes increases the probability of excessive heat energy making its way through the power supply and other circuits. Not a good thing if you want your expensive equipment to last past the warranty period.
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