The Crate BV 120 fuse ?

[gtrplayr1976]

The Crate BV 120 has four .25 amp fuses that tie to the power tube cathode returns. Could these be changed to a higher rated fuse without causing more issues ?

Thanks , Tom

[Jazz P Bass]

The fuses themselves do not "cause" anything.
They are there to protect the circuit if a tube draws too much current.
If you were to put in a higher value (in amps) fuse it will "cause" no harm in a working amp.
What you want to consider is what happens if a tube goes gonzo.
Then what protection do you have?
Too much in my mind.

[Steve Conner]

Also, why do you want to change them for bigger ones? "Because they keep blowing" is not a valid reason

[gtrplayr1976]

The fuses themselves do not "cause" anything.
They are there to protect the circuit if a tube draws too much current.
If you were to put in a higher value (in amps) fuse it will "cause" no harm in a working amp.
What you want to consider is what happens if a tube goes gonzo.
Then what protection do you have?
Too much in my mind.

Thanks Jazz , All I wondered was if it was really necessary to have such a small value. I was thinking it may be harder to find the 1/4 amp fuse ,but I found them at Radio Shack.

[gtrplayr1976]

Also, why do you want to change them for bigger ones? "Because they keep blowing" is not a valid reason

LOL...no just one blew, and I think the tubes are just bad. So...you wouldn't recommend a piece of copper tubing in place of the fuse ?

[Jazz P Bass]

That specific value fuse was chosen for a reason.
A 1/2 amp fuse would work fine.
It will still blow, the same as a 1/4 amp.
(in the event of a catastrophic tube failure)
But, it is twice as large as the 1/4 amp fuse.
So it will pass twice as much current.
Is that harmful?
You would have to study the circuit to make an intelligent decision.

[gtrplayr1976]

A 1/2 amp fuse would work fine.
It will still blow, the same as a 1/4 amp.
(in the event of a catastrophic tube failure)
But, it is twice as large as the 1/4 amp fuse.
So it will pass twice as much current.
Is that harmful?
You would have to study the circuit to make an intelligent decision.

Probably just as easy to stay with the 1/4 amp. Thanks Jazz

[Enzo]

1/4 amp is 250ma. And that would be a lot of current flowing through a power tube.

[gtrplayr1976]

1/4 amp is 250ma. And that would be a lot of current flowing through a power tube.

Thanks Enzo. Yeah I guess that is a lot of current.