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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
yogiboy's avatar
yogiboy
5,714 posts
 
" Me being one of the few actually has common sense "
Talk about an inflated ego!
auxinput
2,920 posts
 
As far as the OP issue is concerned, I am wondering if he is using a FAST BLO fuse in a device that really needs a SLO BLO fuse.  A FAST BLO fuse can blow really fast on devices that have a big inrush of current from the transformer (i.e. a device that does not have a soft-start circuit).  In this case, switching to a SLO BLOW fuse should solve the problem.
twoleftears's avatar
twoleftears
5,318 posts
 
Littelfuse make audiophile-grade fuses and are a reputable and reliable fuse-making company.  If you must experiment, get a 5A from them.
auxinput
2,920 posts
 
Littellfuse makes a 285 series in the small 5x20mm size that twoleftears is talking about.  It is available in either gold-plated or rhodium-plated end caps.  The problem is availability.  Both Digikey and Mouser have them in the catalog, but only actually have very limited sizes in stock.

Digikey stock:
https://www.digikey.com/catalog/en/partgroup/285-series/76506

Mouser Stock:
https://www.mouser.com/Circuit-Protection/Fuses/Cartridge-Fuses/285-Series/_/N-ba8h0Z1yzvvqx?P=1yzv7...

Digikey has a rhodium-plated 5A version.  Mouser has the gold-plated 5A version.
dhite71 OP
331 posts
 
@auxinput     I did get the correct SLOW blow fuse so this was not the issue.  I value what the MFG recommends.  They advised me to never put a larger value fuse in any component as this is how the safety features are designed.  Seems some of us are finding no issue with that strategy but I am not comfortable to roll the dice with my gear.  
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