Oops! Need some advice on fuses for JR149 speakers

[Beechwoods]

:o :o

Full volume for 1 second then......

Due to a 'programming error' I pushed my JR149's too far and the fuse in each has blown.

I've had the bottoms off and the fuses therein are 1¼" long, and labelled (A) BS2950A 1.5A

I believe this is a 1.5A Fast Blow fuse but wanted to check with someone who could confirm :)

I've a feeling this one from Maplin might be the ticket, but not sure whether the voltage / breaking capacity was OK for this application:
http://www.maplin.co.uk/11-4in-31mm-quickblow-f-461

Order Code
. GL76H
Rating
. 1.6A
Voltage
. 60Vac
Breaking capacity
. 100A

Thanks chaps. I need to get this sorted tomorrow. I can't be without my speakers!

[The Grand Wazoo]

This old Gramophone review talks about it being 2 Amps Nick

http://www.google.co.uk/url?sa=t&source=web&cd=13&ved=0CCoQFjACOAo&url=http%3A%2F%2Fwww.gramophone.net%2FIssue%2FPage %2FDecember%25201981%2F144%2F758075%2FJR%2B149%2BM k.%2B2%2Bloudspeaker&ei=QcPJTfzJJcSwhAfa1dmsDQ&usg=AFQjCNH4pCVp-qTBlEPoK-fxvCYYfGj-GA

Fast blow would be correct, I reckon.

[The Grand Wazoo]

........but this refers to 1.6 & 1.5

http://www.audiokarma.org/forums/archive/index.php/t-210537.html

[Beechwoods]

It seems that the spec varied over time.

Mine are labelled 1.5A...
This page (http://www.jr149.pwp.blueyonder.co.uk/The%20crossover%20to%20149-4.htm) has 1.6A for the last JR149 design.
And the Mk2 had 2A according to Gramophone and elsewhere!

:scratch:

Mine are matched and look like they're probably original.

Does the voltage rating make much difference in this kind of circuit?

[spendorman]

Both my pairs of JR149 are in storage, but I remember that there is a small poly bag with a spare fuse inside, tucked in the crossover of each speaker. If that bag is not there, it is possible that the fuse has blown before.

[Reid Malenfant]

Does the voltage rating make much difference in this kind of circuit?
Not in the slightest :)

[Beechwoods]

That's good! I went with the Maplin ones and they're back in the land of the living now :hifive:

[Reid Malenfant]

60V AC is equivalent to about 450W RMS 8ohm, i somehow doubt you are feeding them that so the fuse is good :eyebrows:

Breaking capacity refers to the maximum voltage it's safe to use the fuse at & guarantee that it won't conduct when it has blown.

[Alex_UK]

That's good! I went with the Maplin ones and they're back in the land of the living now :hifive:

Phew, glad you're sorted Nick - always a worry when those kind of things happen that its only the fuse.

[spendorman]

Well, it looks like Jim Rogers got it right!

[Beechwoods]

Phew, glad you're sorted Nick - always a worry when those kind of things happen that its only the fuse.

It did give me a moment for reflection! I've had speaker fuses blow before without other ill-affect but it's always worrying when it happens!

[Beechwoods]

60V AC is equivalent to about 450W RMS 8ohm, i somehow doubt you are feeding them that so the fuse is good :eyebrows:

Breaking capacity refers to the maximum voltage it's safe to use the fuse at & guarantee that it won't conduct when it has blown.

Thanks Mark, useful to know.

The very first 149s didn't have fuses so I'm thankful that mine did or I might have been looking at new tweeters!

[spendorman]

A few years ago, my cosmetically immaculate Radford ZD50 was feeding B&W DM5's (not that loud), when all of a sudden one channel went dead.

The ZD50 had thrown a wobbly and put heavy DC into one speaker. This is despite it's protection devices.

Fortunately, the 2A fuse in the DM5 blew, speaker was fine after fitting a new fuse. Amp still needs looking at.