Fuse types for 6v6 build.

[g1]

When I was working on the heater core in my old pickup truck, I found one of those 350A's in the ductwork. Fortunately it had never "nuisance tripped" .

[wozt]

Hi. sorry for the delay in responding.
I only have 1 internal fuse, it is contained within the ac receptacle I fitted on the back of the chassis and has neon indicator. Using this just seemed easier, however, it has no mojo at all. So indeed I have 2 fuses that are in series from the wall outlet to the primary of the PT.
250ma was all I had in my bits box but I have some 500ma and 1amp on the way. I am liking the idea of a HT fuse.

[Leo_Gnardo]

I only have 1 internal fuse, it is contained within the ac receptacle I fitted on the back of the chassis and has neon indicator. Using this just seemed easier, however, it has no mojo at all. So indeed I have 2 fuses that are in series from the wall outlet to the primary of the PT.
250ma was all I had in my bits box but I have some 500ma and 1amp on the way. I am liking the idea of a HT fuse.

So you had a 250 mA line fuse in a 2x6V6 amp powered from 240VAC and it was popping. Nothing unusual about that. I expect the 500 mA will hold and provide sufficient safety margin. With tube gear the slo-blo or time-delay version is recommended. There's a switch-on 'bump' in current for half a second or so as cold tube filaments start to warm up and hi voltage filter caps charge.

[wozt]

Thanks. Do you implement a HT fuse?

[Leo_Gnardo]

Thanks. Do you implement a HT fuse?

I do mostly repairs not building. Rare to find HT fuse in older amps aside from Marshall, Hiwatt & similar. In recent years safety requirements for some countries have manufacturers putting HT fuses in many amps. And filament fuses besides (?!?) in some cases even the bias supply is fused . What's the point in those last two I can't imagine. I think some places have gone fuse-crazy .

Whether to HT fuse your amp, it's all up to you.