Fender Fuses

[russix]

I have received a Fender Power Chorus that is missing its fuse. Do all Fender Amps use the same fuse? What kind of fuse does this take?

Thanks!

[Enzo]

No, all amps do not use the same fuse. A tiny Champ will have a much smaller fuse than a giant Bass rig.

Look in the schematic.

Mine says 4A fuse.

Does the board not have the fuse type silk screened on it by the fuse clips? SOmething like "Use only same type fuse..."

Before you slap a fuse in it, get out the ohm meter and make sure none of the output power transistors are shorted. Must be some reason there is no fuse in there.

[russix]

It would be nice if the equipment had its fuse specification labeled somewhere on it. The fuse was removed and the owner lost it. I also having trouble finding the correct schematic for it as well to reference. Here's the serial number if anyone knows the fuse specs or has a schematic. LO-98967

[Enzo]

I do have the schematic, it says a 4 amp fuse, like I said.

Did you look on the circuit board near the fuse to see fi there was lettering about that fuse? Fender usually includes that there.

[Brad1]

Maybe someone should tell him the voltage rating for that 4 amp fuse, also...just to keep him from putting in a 4-amp 250V instead of 4-amp 125V...or vice-versa?

Brad1

[Enzo]

Voltage rating won't make a difference. In the USA, he'd have a hard time finding a 4A 125v fuse anyway. The voltage rating is how high a voltage the fuse can interrupt without arcing. You can always use a higher voltage rated fuse. It will break on the current, not voltage. Even using a 32v fuse, the likelihood of arcing in that application is vanishingly small.

Plain old vanilla 4A fuse. Radio Shack should have them.

[russix]

Can anyone post or send a schematic for this Power Chorus to russix(at)gmail.com.

Thanks for your help.

[Brad1]

Hmmm...I wasn't completely sure about that. But I did find this blast from the past:

http://www.firebottle.com/fireforum/...6861449Qpg21bN

I think I was assuming that if it called for a 125V 4A...and a 250V 4A was used, then the 250V 4A would actually look like a 2A for that circuit. Or is that backward...is it 8A? (Juggling these formulas around, and math especially, was never my strong suit. That's why I only try moderate repairs on these things, and not mods)

Anyway, I thought it may be OK to use a higher voltage rated one, but not a lower one, and that even then it wasn't advisable. I think I was thinking in terms of wattage, but didn't know how that would translate to current-handling capabilities, and it may either blow too soon, or not soon enough to protect the amp. 125Vx4A=500W...250Vx4A=1000W. Maybe this has nothing to do with that?

So, it appears my thinking is wrong. It IS, then, OK to use a same amperage rated fuse of double the voltage rating? Is it ever advisable to use 1/2 or double amperage rated to convert 250V to 125V rated, and vice-versa? Obviously, using the same fuse is OK, because all kinds of stuff has voltage switches, and use the same fuse.

I'm still confused. I can't seem to wrap my tiny little brain around this. Maybe it's one of those cases like one of those logic test questions where they insert all kinds of irrelevant info. "You are trying to use TOO MUCH information. It doesn't matter that the car is blue, or that the man is 5'9" tall, or that his coffee cost $4.95 at Starbucks! Cross those out and figure out the problem."

Thanks,

Brad1

[J M Fahey]

Brad, only current rating matters. Have fun with your amp.