that BS 2950A 15A seems way too big
don't

I can't explain why the different standards and can only guess

British may just be assuming the National standard voltage (250/230 I think )

I think your Mic-pre want 1/4 amp... 250 mA (milliamps)

It's FIRST thing in the morning for me
so my brain is very BLURRY

I'm guessing you are 110V out of the wall ... then the converter to 230/250V for the ART dual Tube MP

you want a 250 to 500mA fast ... perhaps a slow blo fuse if there is a Toroid power TX in there

hope that doesn't confuse you more

OH !
and one of those 4 channel API in 1ru is a cool thing .. 3124 ... I think
brain blurrr ... need cofffeeeeee

hey, good morning and thanks for the response.
i'm actually 220 out of the wall (when it is working) and convert that to 110, but i guess that the fuse is still wrong... unfortunately, it is the closest and only fuse the same physical size in the whole of this stone-age country.
so i guess i'm out a mic pre for a while...
that 3124 is the exact pre that i am lusting over!

yes the fuse is wrong

that 15A is the thing to worry about

BUT
if you are 220 and convert to 110
why is the original fuse
250V BUS MDL 1/4 .... 250volts ??

That Bus fuse should have a current rating on it - try the other end cap.

From what you say, the fuse is inside the Art Dual Tube MP, and so will be in the 110V circuit. The manual says unhelpfully that the product is "internally fused" and consumes only 10W. If you can't find a current rating on the blown fuse and your only other 1.25" fuse is 15A, don't fit that - if there really is a fault that caused the original to blow, the mains transformer will burn out before the 15A fuse does.

If you can get hold of a 20mm 2A fuse, it is possible with a bit of nifty soldering to construct a replacement 1.25" fuse from the body of the old one fitted with the 20mm fuse internally. I once managed to do this embarrassment-saving trick in a dark corner of a stage with only two minutes to go before curtain up.

thanks for your input!
power here is terrible, cutting, surging, dimming... even though i have four surge protectors between wall and gear, i think i'm a little dumb not to have a power conditioner...
yes, that ART manual is little help, and i bought the pre used, so not sure if that fuse is even original.
i thought of modifying a smaller fuse, but as that pre is not mission critical, i think i will have a friend who works at a music store in civilization mail me the fuse! whether it actually gets here is another story...
i think the audio gods are giving me a sign that i should not be using ART. the API gods are beckoning...