Slow Blow or Fast Blow Fuse for my Sugden A21 original Class A amp!!!! PLS HELP

S

spence

Audiophyte
Hi there, i have a sugden A21 class A amp from 1968!I have enjoyed the sound from it for many years! but my left channel blew the other day! I opened her up to check the fuses and the left channel fuse had blown!!! I'm in destress as i can't seem to find any info regarding which fuses were used! and all the newer fuses have new markings on them. the fuse reads 1A 250V THEN INSIDE A SMALL CIRCLE (ul) THEN AGAIN IN A SMALL CIRCLE THERE'S A DEFINITE (S) AND MAYBE AN (A OR B) CAN'T MAKE IT OUT! Any help would be much appreciated as i am currently without my music at the moment i'm sooooooooo stressed out!:confused:
 
Rickster71

Rickster71

Audioholic Spartan
Hi Spence welcome to Audioholics.
If you are sure they are the original fuses. (check to make sure they're both the same)
Bring them to an electronics repair shop or if you have Radio Shack near you, and have them check for a compatible replacement.
Here is a link to Sugden Sugden Audio: Home to get info on the correct fuse.
It may be best to have a tech look at the amp to make sure that something else isn't causing the fuse to blow.

Good Luck
 
S

spence

Audiophyte
Thank's Rickster, i was thinking about getting in touch direct with Patrick Direct at sugden to ask for a full service at some point! looks like theres no time like the present m8! both the amps are the same and i think are the original fuses which were installed! But to be sure i will take it to Sugden as i live literally 15 mins drive away! Thanks for the info pal
 
J

JLoving

Audiophyte
If all else fails you can always use a Fast Blow no matter what, just don't use a Slow Blow if you are not sure which type.
 
Pyrrho

Pyrrho

Audioholic Ninja
If all else fails you can always use a Fast Blow no matter what, just don't use a Slow Blow if you are not sure which type.
Yes. The worst that could happen would be that the fuse would blow too easily, but it would not hurt the amplifier regardless of whether a fast or slow blow fuse was intended. It is when one puts in a slow blow fuse where a fast blow fuse belongs that there can be serious trouble.

In this case, though, he is well-advised to contact the maker of the product and find out what is supposed to go into it, and then get the right fuse.
 
TLS Guy

TLS Guy

Seriously, I have no life.
Hi there, i have a sugden A21 class A amp from 1968!I have enjoyed the sound from it for many years! but my left channel blew the other day! I opened her up to check the fuses and the left channel fuse had blown!!! I'm in destress as i can't seem to find any info regarding which fuses were used! and all the newer fuses have new markings on them. the fuse reads 1A 250V THEN INSIDE A SMALL CIRCLE (ul) THEN AGAIN IN A SMALL CIRCLE THERE'S A DEFINITE (S) AND MAYBE AN (A OR B) CAN'T MAKE IT OUT! Any help would be much appreciated as i am currently without my music at the moment i'm sooooooooo stressed out!:confused:
Sugden are still in business and will get you sorted out.

Readers here will not be familiar with this classic solid state integrated amp from the "Golden Age of British Audio." This is from an age before the Far Eastern manufacturers condemned the world to mediocrity. This was the world's first class A solid state amplifier. Not only that it has proved to be the most reliable and durable class A design to date. In general class A amps are not durable because of the high quiescent current through the power transistors. This amp is an exception to the rule in this regard.





I would definitely have Sugden check this amp out, as the power transistors have likely finally failed after 44 years of use.

I used one of these amps for my sister back around 1966, with JW modules in a labyrinth bookshelf speaker system I designed and built. The system is still going strong. She and her husband love it and it still sounds a lot better than the vast majority of small bookshelf systems available on the market today. That system makes a really good argument for full range drivers.

The A21 was also produced by Richard Allan for quite a few years under license.

They are absolutely fabulous units and quite rightly fetch much more than their original purchase price on the second hand market.

Certainly get that amp fixed as they are almost certainly the best integrated amps in the 10 watt per channel class ever to be made available.
 
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