Vintage fuse holder

[Joe Shmoe]

I acquired on old 1970s amp, and it's missing one of its two fuses.

Here's a photo of the remaining fuse, and it's cap, or holder. I'm not sure of the terminology.

Where can I find another like this, as I'm missing the fuse and it's cap, plus the black bit, which isn't a necessity I guess?

Also, what rating fuse should I use? I'm guessing 13amp?

Editted to say, I think the fuse looks longer than the conventional modern ones I'm used to seeing in plugs? Do me need a special size?


Thanks.

 

[AJB Temple]

Be careful! You can really screw up amplifiers by getting this wrong as it is easy to blow transformers for example and these are expensive. Is it a transistor or valve amp or a combination of the two? Is it a musical instrument amp or a hi-fi amp? There are a lot of resources on-line from guys who are into valve amp design e.g. http://www.valvewizard.co.uk/fuses.html

You need to know (if it is a valve amp) if the fuse is protecting the main input, the transformer or possibly the heater. Despite having a few of them I am no valve amp expert so I would do some research on line about your specific amp if I were you. If you are stuck I can put you in touch with a clued up value amp repairer (if he is still working).

 

[n0legs]

Looks like it could be a 32mm fuse. Look for a Durite panel fuse holder, should be a couple of quid.

edit
Duirite 5-591-50 might do the job. Can't give a link but it's on the Inter Parts site.
Ebay have a couple of inch and quarter vintage fuse holders.

 

[Racers]

Yep 32mm or 1-1/4" in the old money, I have some from 100mA to 10A.
You need to use the right value it could be a low value if it's the HT fuse.
I might even have a spare fuse holder.

But safety and danerous voltages are something to think about.

Pete

 

[Paul Hannaby]

That fuse appears to have 2 amps written on it so I would go for another one the same in the other holder.

 

[Racers]

That fuse appears to have 2 amps written on it so I would go for another one the same in the other holder.

That a dangerous assumption. I would try to find out the rating.

Pete

 

[mind_the_goat]

Also, what rating fuse should I use? I'm guessing 13amp?

Almost certainly never 13 Amp. The assumption that anything that has a 13A plug needs a 13A fuse is a dangerous one. The only things I can think of that are likely to need a 13A mains fuse are heaters and some workshop machinery.
If the fuse is missing it may have been removed because it blew, which means there could be a fault, if you replace it with a higher rated fuse and there is a fault, the fuse may not blow, and will cause more damage.
It's not even clear if this is protecting the input to the transformer or something on the low voltage side. The only guide might be if the amp is clearly split into 2 identical circuits, left and right, then it might be safe to match the remaining fuse, assuming the other one is the original value. Keep in mind that fuses have more than a current rating, there is also a 'speed' rating, prefixed with a 'T' IIRC, it would be good to get that right too.
You could replace the whole fuse holder, or both to match, if you can't find one to match yours for parts. Maplin would be as good a place as any to buy some new ones.

 

[Eric The Viking]

The fuses involved here are probably NOT mains fuses (unless it says so). They are likely to protect various power rails/components inside the amp, or the output stages.

If it has valves, the arrangements will be quite different, and the fuses in different places in the circuit.

As others have said, you need to know what you're doing, BUT there's nothing magic about the physical size of the fuse. The important thing is using the correct type and current rating. As Rob says above, other fuseholders are available that will possibly do instead of the older ones originally fitted, for example 20mm types. As long as you know the correct value for the fuse you could swap out the entire fuseholder for one that takes a more commonly available size.

I have reservations about Maplins though: their components often tend to be of the cheapest quality and are very expensive considering what they are. And they nowadays stock such a limited range of electronics stuff that they're frustrating (they make much more money from selling gimmics to the masses). In times past they sold some excellent stuff, notably some nice toroidal transformers and some good amplifier kits, but most of that is long gone now.

You really need to find or work out a circuit diagram for the amp first, so that you know what's needed. If it's an output fuse, it may depend on the loudspeaker(s) connected, too.

It's all do-able, but you may need someone with expertise to help you.

Can you post up more detail on the amp concerned, and pics? Geeks want to know ;-)

E.

 

[Joe Shmoe]

Cheers guys, some excellent advice in all your posts and it certainly pushed me in the right direction. I had no idea about the repercussions on the fuse etc.

After Google search looking for more information on the fuse, I found a forum where someone had the same amp (it's a guitar amp) and after a quick FB message, he confirmed the fuse should be 1a, and not 13 (which you all said it wouldn't be anyway).

Thanks for the advice, if not for you I'd have chucked a 13a in there lol.........

 

[lurker]

Have you checked it's 1 amp at 240 v ac ?

I might have some fuse holders and maybe fuse elements if I can find them you are welcome to them.
Where abouts are you, roughly?

 

[lurker]

Have you checked it's 1 amp at 240 v ac ?

I might have some fuse holders and maybe fuse elements if I can find them you are welcome to them.
Where abouts are you, roughly?