AGX 5A 250v fuses

[Northwinds]

Having a hard time finding these. All the 5a 250v fuses I see have the thin wire while the AGX versions I see in images look totally different. I went to RS to get fuses, unfortunately the 5a 250 fastblo fuses seem to be their best sellers and were out of stock. I had to settle for some 4A 250v fastblo ones for now. Can someone explain the difference since the plain thin wire ones I have been getting don't last long. I am thinking this is the reason I am going through fuses with my 400, they seem to pop with transient peaks at nowhere near max output level. The AGX look better made with the metal tabs on either end joined by the thin wire. Do the plain thin wire versions pop faster then the AGX's?

 

[BubbaH]

Im no expert on this stuff. As I mentioned before my 1801's take 10 amp fuses. These are the style I run in them.

http://www.alans-sales.com/popup_image.php?pID=740&osCsid=1fd73grba5s99br5r6hh25nul6

These particular ones take a lot longer to burn out. Naturally just by looking you could tell it would be a stronger fuse than the simple wire ones.

 

[Northwinds]

I believe the 400 requires fastblo fuses??? Those are slowblo that you posted and I am afraid of damaging something running those types. Honestly, I am not even sure why these fuses are going, the amp sounds perfect. Usually the leftside one goes but yesterday, the right side one went

I seriously wish someone who is a member local to me can stop by and see what I mean. Looks like Joe is closest at 40mins from me

If someone here has the correct fuses available, I would take 6-10 of them so I don't have to keep looking for them. PayPal ready

Im no expert on this stuff. As I mentioned before my 1801's take 10 amp fuses. These are the style I run in them.

http://www.alans-sales.com/popup_image.php?pID=740&osCsid=1fd73grba5s99br5r6hh25nul6

These particular ones take a lot longer to burn out. Naturally just by looking you could tell it would be a stronger fuse than the simple wire ones.

 

[BubbaH]

I was under the impression that as long as the values were the same, it didnt matter. Could anyone explain why an amp could only have fast blow fuses in them?

 

[Northwinds]

I was under the impression that as long as the values were the same, it didnt matter. Could anyone explain why an amp could only have fast blow fuses in them?

I just checked the 8A AGC line fuse and it's a skinny wire version also??? The two supply fuses require AGX 5A 250v types. All appear to be fastblo versions and they look identical regarding the plain skinny wire???? I am confused as they look like the same type fuses and differ only in amperage rating

Regarding your question, I can only assume a fastblo fuse will protect an amp better from surges/spikes. A sloblo version could allow damage???

I am wondering if I should employ a power conditioner but I can't see why, back in the late 70s when these amps came out, I am sure dirty voltage was far more prevelant. My house wiring is fairly new (12 years old now)

 

[BubbaH]

Yeah we were told not to run skinny wire fuses in our 1801. As soon as the amp would get warm, they would pop. Even on thermal cut out i dont think I have ever blown a slow blow.

 

[frhodes]

I was under the impression that as long as the values were the same, it didnt matter. Could anyone explain why an amp could only have fast blow fuses in them?

You want fast blow fuses in an amp so it immediately cuts power before your components are damaged.
Different manufacturers use different types of filaments but if they are rated the same in amperage they will achieve the same effect.

AGC are 1.25 x .25 inches. AGX fuses are 1.00 X .25 inches. (AG stands for all glass.)

Look on Ebay or bizrate for AGC 5 AMP (250 V)

Some hustlers sell fuses they say are for Marantz or Phase Linear and charge 5 or10 times the price for the same fuse you can buy for pennies.
(the same is true for lamps and belts)

 

[BubbaH]

You want fast blow fuses in an amp so it immediately cuts power before your components are damaged.
Different manufacturers use different types of filaments but if they are rated the same in amperage they will achieve the same effect.

Hey thanks for that bit of info. Does convect and fan cooling make any difference in fuse choice? We believed the amps own heat was causing fuses to pre maturely pop. Hence switching to the slow blow. I guess extreme draw on the amp was also a factor.

 

[Northwinds]

Look on Ebay or bizrate for AGC 5 AMP (250 V)

The amp says right on it AGX 5A so your saying it's ok to put AGC types in that supply application??? I suppose they world work depending on the spring inside allowing the extra lenth. The line fuse is an AGC though and that one has never popped

 

[frhodes]

The amp says right on it AGX 5A so your saying it's ok to put AGC types in that supply application??? The line fuse is an AGC though and that one has never popped

If it says agx then the holder on the amp is designed for 1 Inch fuse. You should get AGX 5 amp 250 V. If it says AGC the holder is designed for 1.25 inch fuses, AGC. I believe the reason they used two different sizes is so you don't mix them up.

 

[frhodes]

If it says agx then the holder on the amp is designed for 1 Inch fuse. You should get AGX 5 amp 250 V. If it says AGC the holder is designed for 1.25 inch fuses, AGC. I believe the reason they used two different sizes is so you don't mix them up.

Best place to order is Digikey. 65 cents each $2.92 First class mail up to 8 ounces if you can't find them locally.

http://www.digikey.com/classic/Ordering/AddPart.aspx

 

[frhodes]

Hey thanks for that bit of info. Does convect and fan cooling make any difference in fuse choice? We believed the amps own heat was causing fuses to pre maturely pop. Hence switching to the slow blow. I guess extreme draw on the amp was also a factor.

Heat and cooling shouldn't make any difference. You should never use slow blow fuses in place of fast blow fuses. If you have a problem
blowing fast blow fuses you have a problem with some component in the amp. Using a slow blow fuse can blow additional components.

 

[BubbaH]

Thanks for the answer to the heat question.

Never had a problem running the slow blows. Have been, when the units are running, for 20 years or so now. One of the amps has a smoked channel from the DC offset, the other has been acting goofy, so I just unhooked it.

 

[laatsch55]

Slo-blo's are for the mains in. They have to deal with inrush, so they are costructed with the thin/wide pattern. An AGC WILL FIT if you are gentle. I have done it many times. It will collapse the spring enough that an AGX may be loose if you run them AFTER an AGC.

 

[laatsch55]

Fusing of the +/- rails LIMITS the damage, it can in no way prevent it, way to slow for that.

 

[BubbaH]

Fusing of the +/- rails LIMITS the damage, it can in no way prevent it, way to slow for that.

Are you speaking about the DC offset? I had heard even fast blow fuses cant catch that? I assume thats what youre talking about.

 

[laatsch55]

NO, the +/- rails supply voltage to the amp components. DC offset is present on the signal path as a result of non-symmetry of the input stage. DC voltages of 1 volt or over on the speaker outputs mean serious trouble. Only a circuit and a relay designed to sense DC on the signal will get the signal path off line before damage is done to the speakers.

 

[BubbaH]

Hahah, Ok, thanks Lee. You guys are way over my head with all this stuff anyways.

 

[laatsch55]

Not as over as you think, stick around and we'll get ya knowed up.

 

[BubbaH]

Hey im not going anywhere Lee.