Gibson GA-25 fuse value

[Randall]

A 1948 Gibson GA-25 came to me with a 10 amp fuse in it. The schematic does not show the value. Based on the tube compliment I am guessing 2 amp?

http://archive.gibson.com/Files/schematics/ga-25.gif

[nevetslab]

2A sounds about right. How much AC mains current does it draw @ idle? I'd guess around 600-700mA at best. The Vox AC30-CC2X draws 620mA @ idle, with a few more tubes than this, though it's not using the older 6-series octal socket tubes.

[Enzo]

Find something similar and compare.

Looking at a Fender Deluxe like the AA763 - first one I came to - as similar. Rectifier tube, a pair of 6V6, and four preamp tubes. Darn similar to your amp. It has a 1 amp slow blow mains fuse. The Deluxe Reverb has three more small tubes and still a 1A slow. The Deluxe really is equivalent, at least in my mind.

So 1A slow appeals to me. If 2A makes you more comfortable, sure, why not.

[Randall]

I tried a 1A at first, it blew.

[Enzo]

If 1A slow goes, then use a 2A slow.

Did you do nevetslab's suggestion? Measure current draw?

[Enzo]

HAve we checked for leaking caps and stuff yet?

[Randall]

Not checked for leaking caps and stuff. Yet. Too early, it is a new purchase. But some of the filter caps are fresh, and it does have a new power cord.

[mozz]

You can get these for $15, easy and simple to measure your current draw, i leave mine plugged in the power strip.
https://www.amazon.com/P3-P4400-Elec...ZYTX28HKDB6SCM

[Randall]

OK, it's pulling about 0.5A at idle. Not sure why the 1A I put in blew, I guess it could have been a fluke.

[g1]

There will be a surge at turn on.
Like Enzo mentioned, you are using slow-blow?

[Randall]

No, I think it was 1A fast. There is a 2A slo-blo in it now.

[Enzo]

The 2A should be fine, but the 1A really needed to be a slow blow.