5V4 in Champ

[dombrowskim]

Hello,

Can anyone tell me why a 5V4 rectifier tube blows the fuse in all of my SF Champs (I have three)? It seems many use this tube with no problem. I can run a 5U4 (3amp filament) with no problem.

I have a 100R resistor after the recto and before the first cap to slow down the "in-rush" but it still pops my slo-blow 1 amper after about 5 seconds.

I'm puzzled!

[Jazz P Bass]

5V4 rectifier

Not near the same tube.
5V4 has a indirectly heated cathode. Longer warm up time.
The output voltage is higher.
The current that it can supply is lower.
How about a 1.6 amp fuse?

[Tom Phillips]

How many different 5V4s do this?
If you have been trying the same one over and over then it seems to me that you have a bad 5V4.

[dombrowskim]

Thanks for the replies!

I've tried two NOS GE 5V4s. Perhaps it's the way the tube heats that blows the fuse. I'll have to locate another tube or just stick with the 5Y3 or the 5U4. I'm trying to get a bit more volume and headroom without major mods.

How many different 5V4s do this?
If you have been trying the same one over and over then it seems to me that you have a bad 5V4.

[Tom Phillips]

Sure seems like it should work fine.
Both of your 5V4s could be bad. Similar things have happened to me.
Frustrating but it does happen.