B+ fusing?

[Colossal]

Anyone have a particular preference when fusing the B+ side? Pros and cons, if any?

Options
a) Meh, don't bother (most classic amps)
b) Fuse the PT's center tap to ground (but this still leaves the secondaries energized in a fault condition)
c) Fuse one or both secondaries (the latter recommended by Merlin)
d) Fuse the OT's center tap
e) Fuse just after the rectifier or between B+1 and B+2 (Marshall)

[martin manning]

The best solution is to fuse both HT leads. But you knew that already...

[Colossal]

The best solution is to fuse both HT leads. But you knew that already...

Yeah, that's what I do now; it makes for a minimum of three fuses on the back. Now I want to individually bias and fuse the power tubes on a particular amp so that's more fuses.

Fuses!

[Gaz]

If you have a bridge recto, you only need to fuse one leg of the HV secondary. With the full wave you need to do both. I always do that now - kind of ignorant not to in a scratch build...

[Bob S]

Yeah - I like the incoming mains fuse on the back.
Then you've got the hv transformer taps, the bias, 5V & 6.3V supplies to worry about.
Just bought a bunch of axial wired fuses.
These aren't very commonly used yet.
If you fuse everything, the only place that makes sense is inside.
Where real estate is at a premium.
Wired fuses don't take up much space on a board.
Or go old school - it's easier.
Hmmm.
Yes - No - Maybe

[Blackburn]

I have my chassis punched so that I can have two fuse cylinders mounted on the back, one being the standard mains and the other for the B+ right off the rectifier. Everywhere else is up to fate.

I have been thinking about using these little internal fuse slots that I scored on Fleabay. I bought them for tweed stuff, where you only get one on top, and they do come in handy, taking up minimal real estate.

[M Fowler]

Main and HT on back the other fuses can go on the inside of the amp.