AR90 Fusing

[SteveS]

The AR90 reference manual on page 14 states to use a Fusetron Dual Element FNM-2 for the following limits into 4 ohms:

25 watts long term average

64 watts for 30 seconds

180 watts for 10 seconds

400 watts for 5 seconds

800 watts for 1 second

The amp I am currently using (a Proton AA-2120) puts out 120 in 8 ohms, 180 into 4 ohms, and has a 2.5db dynamic headroom, which I guess is around 325 for milliseconds.

Anyway, is this fuse quick enough to save the tweeters?

Should I fuse the woofers, midrange and tweeters separately, with different values?

Any opinions/ideas are much appreciated

[SteveS]

Sorry. Didn't see Vern's previous post

[dynaco_dan]

>Sorry. Didn't see Vern's previous post

Hi there;

Now that you saw my previous post;

Which post was that?

What did you think of that information?

Did it help you?

[SteveS]

Your response to Barry regarding Fusing AR-3as

did help me. I think I'll try out the 1 amp fast blow fuse approach, and if it blows too easily, move slowly up from there maybe? (I don't really think I listen that loud, because as a bass player, I value my hearing--I wear earplugs when I go to concerts).

I looked on the Crown site and could not find what you were referring to. DO you have that link, or can you tell me where on the site it is?

Thanks,

Steve

[dynaco_dan]

>Your response to Barry regarding Fusing AR-3as

>did help me. I think I'll try out the 1 amp fast blow fuse

>approach, and if it blows too easily, move slowly up from

>there maybe? (I don't really think I listen that loud, because

>as a bass player, I value my hearing--I wear earplugs when I

>go to concerts).

>

>I looked on the Crown site and could not find what you were

>referring to. DO you have that link, or can you tell me where

>on the site it is?

>Thanks,

>Steve

Hi Steve;

If you have gone to the "other" forum, and copied the more decent copy of the Dyna 416 fusing information I typed in, keep that as a reference, barring someone else disproves that data.

After all these years not very likely, except my guestimates.

The Crown site is part of the Harmon International network.

If you do go and find their site of value, send them a nice thank you via email, let them know how you found their site as well.

They are still going to keep updating it.

The path is;

http://www.crownaudio.com

click mouse on support > technical information > amplifiers > crown amplifier technical information

scroll down page to the section > Other Crown amplifier technolgies

Particularly look at;

How much amplifier power do we need?

I keep mentioning about the Heath/AR speaker 103 system and the relationship of their 3 amp fast blow fuse versus AR's own 1 1/14 amp FNM slow blow fuse.

There is probably a very simple calculation of this relationship that will transpose to the other slow blow fuses versus fast blow fuses.

Keep this relationship information handy.

Now with this information, we should also consider that our drivers have aged, and in the interest of safety, also from blowing out drivers, should keep below whatever we arrive at for a corresponding fuse size.

Definitely I can see individual driver fuses of the correct type and size rating would be ideal, but some work and only a small cost.

Overall, the cost of one blown tweeter would have more than paid for all the parts for a pair of speakers at least.

As a sidenote, I went to Mouser, Cooper/Bussmann, Littlefuse and Steven Engineering (suggested buy a memeber) last night.

The results are, the #4421 Bussmann open style solder connections type, does not seen to be listed anymore by Bussmann.

Mouser lists them as non-stock at $4.80 each 1 - 24 qty.

Mouser lists the #4515, screw connections, as non-stock, at $6.18 each and Bussmann does not seem to list these as well.

The solder type would be preferred.

FNM2 Bussmann fuses at Mouser $4.70 each 1 - 24 qty.

FNM8/10 Bussmann fuses at Mouser $5.44 each 1 - 24 qty.

Steven Engineering wasn't as productive for me.

Littlefuse has the equivalent FLM fuses and you can check them out as well.

The member also mentioned that Lowe's has the fuses at $3.57 each.

I don't know which model of fuses or their values, but being Scottish, the price is right, if they are the FNM's at least.

Good luck.