Bias test points and HV fusing question

[llemtt]

Tom, a fast-blow right before the plate supply caps usually blows as soon as you turn on the amp due to the high charging currents of the first cycles.

It would be better between the plate supply caps and the OT but I never tried such a solution while I reverted to a slow-blow (actually two) before the caps.

Teo

[Structo]

I have several Marshall schematics that show a 500ma fuse on the HT right before the choke.
Maybe it is a slo blo, not sure but that is where they have it.
But it is after the plate filter.

Here is a JCM 800 Lead 50w

[Tonegeek]

I have several Marshall schematics that show a 500ma fuse on the HT right before the choke.
Maybe it is a slo blo, not sure but that is where they have it.
But it is after the plate filter.

Here is a JCM 800 Lead 50w

After the filter is the key, I think. I will go with that or the CT. Its easy enough to reroute if I don't like it.

[llemtt]

After the filter as per the schematic you posted it's ok with a fast-blow

CT or pre-filter as per the attached schema of a reissue plexi 50 requires a slow-blow

Teo