Registered User
Join date: Feb 2012
137 IQ
Is it ok to use a fuse that is rated at 6 1/4 Amp 250 Volt, if the amp is rated for a fuse that is 6 1/4 Amp 125 Volt? If not could someone please point me in the direction of a good website to purchase the correct fuse? I live about 40 miles from the nearest hardware store so I don't go into town often, so a hardware store isn't ideal. I have also searched on Radio Shack and could not find the correct kind of fuse.

Sorry is this was a stupid question, but thank you guys in advance for whatever help you can give me.
Grumpy Old Tech
Join date: Oct 2009
2,565 IQ
Here's how it works. The voltage rating is referring to how it will behave after the fuse blows, not before. A fuse with a low voltage rating may continue to conduct after it blows due to residue if it's across a high voltage. It is only really a concern if using a low voltage fuse like 30V in a high voltage device like 230V (higher really).
A fuse cannot be rated too high in regards to voltage for an application and the difference between 120 and 230 isn't enough to really be a concern anyway. Using a 250V on a 120V system is actually better than using a 120V fuse. The only reason we don't use 1000V fuses in everything is that they cost too much, otherwise nobody would ever use smaller voltage ones.

tl/dr: a 250V fuse will work just fine.
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band