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Large Advent Fusing


Guest Rickman

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Guest Rickman

I am looking to fuse my large advent loudspeakers. I currently have them fused with 1/2 amp slow blow 250 volt fuses. The owners manual suggests to use a 8/10 amp time delay. The issue is that this fuse is no longer available. I want to get more volume, but am not sure if it is safe to use a 1 amp slow blow.

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Rick,

I recently checked at my local Marvac and I believe the FNM 8/10 are still available. Problem is that they run, if I remember correctly, about $12 apiece. With vintage speakers it probably doesn't hurt to run a lower rated fuse like the 1/2 versus the 1.

Just my 2 cents, or $12, worth.

James

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I would use a fast-blo fuse. If there is a large amplitude transcient, the tweeter is likely to blow before the slo-blo fuse.

Usually, a 1 amp fast-blo works pretty good unless you want live rock concert levels.

Doug

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>I am looking to fuse my large advent loudspeakers. I

>currently have them fused with 1/2 amp slow blow 250 volt

>fuses. The owners manual suggests to use a 8/10 amp time

>delay. The issue is that this fuse is no longer available. I

>want to get more volume, but am not sure if it is safe to use

>a 1 amp slow blow.

Hi Ricky;

Please go to the "other" forum and find the, "fast fuse", topic of a few months ago.

Follow the thread down, I wrote from a Dynaco 416 manual.

There is 8 ohm speaker fuses listed.

I also mention Heath/AR's fast blow fuse as a referrence point only.

If you have the AR fusing sheets information from the AR library, use the relationship between the speakers, rated with a FNM slow blow fuse and a fast blow fuse.

The AR-2 series used 8/10 amp fuses as well.

I don't have that information handy at this time to suggest a start size.

Don't continue using the 1/2 amp slow blow fuse or any glass slow blow fuse.

The fuses have a different characteristic.

As always, these manufacturers recommended their fuses, 25 plus years ago, go to a slightly lower, safer rating.

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Guest Rickman

>I would use a fast-blo fuse. If there is a large amplitude

>transcient, the tweeter is likely to blow before the slo-blo

>fuse.

>

>Usually, a 1 amp fast-blo works pretty good unless you want

>live rock concert levels.

>

>Doug

Wouldn't a fast blow cut out when normal peaks are present?

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Guest Rickman

I also found the 8/10 fuse at alan's sales. It was $4 each, and the fuseholders were a older size, so they cost $10 each. That is alot of money just for fusing.

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  • 2 weeks later...

I went with the recommendation of the original Absolute Sound article on "The Double Advent System". They ignored Advent's recommendation and went with AGC 3 amp fuses on each positive side of the speaker leads. Advent wrote back after viewing the article and said that Absolute Sound's fuse recommendations were a "satisfactory substitute for the ones we recommended".

I used standard fuse holders from Radio Shack and wired them right off the back of the receiver for easy access. Probably not the ‘best’ looking fuse setup to grace man, but I don’t see any fault in their function.

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>I went with the recommendation of the original Absolute Sound

>article on "The Double Advent System". They ignored

>Advent's recommendation and went with AGC 3 amp fuses on each

>positive side of the speaker leads. Advent wrote back after

>viewing the article and said that Absolute Sound's fuse

>recommendations were a "satisfactory substitute for the

>ones we recommended".

>

>I used standard fuse holders from Radio Shack and wired them

>right off the back of the receiver for easy access. Probably

>not the ‘best’ looking fuse setup to grace man, but I don’t

>see any fault in their function.

>

Hi there;

Unfortunately, I have yet to find an article regarding an Advent recommended fast or slow blow fuse for the Larger Advent.

I am sure there was one and maybe a new member may have a copy they can download to our site for our future referrence.

I have seen the recommended fuse in the Advent library for the Smaller Advents only.

Yes, they did use 3 amp in that, "Absolute Sound", article, that was then and now we should downsize the rating a bit, to protect our valuable tweeters.

If you check out the, "other", forum and find, "fast blow fuses".

Crown Audio's web site is also referrenced for power handling capacity information.

You will see, I referrenced Heath/AR Heath AS-103 (AR-3A equivalent) speaker system using a 3 amp fast blow fuse with a sealed chassis fuseholder.

The AR-3A can handle a great deal more power than the Larger Advents and I certainly would suggest we err the side of being conservative.

Perhaps someone will explore the fusing of individual drivers in the future, not just Advent, but numerous other classic brands.

Of course, this will mean a sacrifice of some drivers, in testing.

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Hey Vern....the AGCs 3 are fast blow types. I think you're right though, going down to a AGC 1.5 or 2 would offer more protection.

I have this article entitled "Some General Information About 'Double Advent Loudspeakers'". I always assumed it was by Advent Corp, although they never say anything other than "we". In this article they talk about MDL 2 (or 1), 3AG 2 amp slow blow (or 1 amp slow blow), FNM-2 (or FNM-1) and ordering the fuses and fuse holders from Advents' Customer Relation Dept. This was back in the day and I have corresponding diagrams that show their use depending on if you're using A+B, A+C, or just going parallel off of a A, B, C with the double setup. Then there is a placement diagram for suggested ways to place your double set in a room-which I always thought went with the Absolute Sound article....but maybe it's part of the above? I never throw anything away, as I’m the ultimate packrat although stuff has gotten destroyed or stolen.

Anyway, I can't scan (no scanner)...but I think I loaded this all on CD at Staples and posted it at another speaker site ages ago. If anyone is interested and I can find it, I'll email the whole thing and then it can be uploaded here....I don't think you want me to try and upload it here myself.;-)

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  • 4 months later...

I am currently running stacked double New Large Advents with two Phase Linear 400 amps. I have refrained from playing anything too loud for fear of blowing a tweeter pushing 200 Watts RMS into each speaker. I just finished fusing the speakers with Philmore H108A fuse holders and AGC 3 fuses. The fuse holders are attached to the cabinets and soldered inline to the speaker wires. So far there is no noticable diminishment in sound and I have played various music tracks much louder than I can listen to for an extended period of time.

I went the route I did due to the classic Absolute Sound article from 1973 which states, "In fusing the Double Advent System, we ignored Advent’s recommendation and used AGC 3s. These fuses, used in conjunction with the Phase Linear 700, do not blow until the speaker is being fed 60 watts rms steady loads (that represents zero on Phase Linear’s averaging meters). Any sudden transient through the system (a dropped tone arm, a faulty switch) will blow the fuses and protect the Advents. With the Phase Linear 700 and the Double Advent System, you seldom have to worry about hitting the “zero” meter reading mark; few records will even push the Phase Linear meters past the “minus 20 kdB” point". This article does not say how the stacked double Advents are hooked up (series or parallel, but most likely in parallel) to the Phase Linear 700 or how they connected the fuses. I just assumed that one fuse per positive speaker lead (8 Ohm designation) would do the trick. Without knowing the electronics behind it I am hoping that each speaker will not be fed much over 60 watts RMS from the 200 watts RMS channel of the Phase Linear 400 before a fuse will blow.

Whadaya think?

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>I am currently running stacked double New Large Advents with

>two Phase Linear 400 amps. I have refrained from playing

>anything too loud for fear of blowing a tweeter pushing 200

>Watts RMS into each speaker.

Always remember that we own hifi not disco speakers.

They were never meant to be driven at disco sound level's.

I just finished fusing the

>speakers with Philmore H108A fuse holders and AGC 3 fuses.

This was the size fuses they wrote that they used in that review.

That was many decades ago.

Now we need to look at fusing from a different perspective.

A very kind member downloaded Advent fusing information to our site.

They recommended the same size slow blow fuse for The Smaller and The Larger Advents.

Buss FNM 8/10 amp slow blow fuse, or, of the FLM slow blow Littlefuse brand, if I remember correctly was the fuse that Advent recommended, THEN.

With this particular fuse, it offers very little protection to the tweeters.

If I could experiment, I would quite likely use a downsized FNM-6/10 fuse for the woofer and a 3/4 or 1 amp, in that range at least, fast blow fuse for the tweeter.

Yes, this would require 2 external fuseholders, and the related wiring mods, or even two chassis mount style fuseholders.

>The fuse holders are attached to the cabinets and soldered

>inline to the speaker wires.

This is what James took a photo of last year, on his speakers.

He did a very professional job of mounting the fuseholder and the crimp type connectors.

He used an open style fuseholder, which also allows the fuse to cool, and mounted it to the rear of his speaker.

This may be the better location or at the rear of the amplifier, whichever is easier to get at when the fuses blow, and also not short.

So far there is no noticable

>diminishment in sound and I have played various music tracks

>much louder than I can listen to for an extended period of

>time.

Many moons ago there was controversy regarding fusing and the effects of the damping factor.

The fuse is actually a small inline resistance which does affect the damping factor.

But, to be realistic today, decades after our manufacturers have gone out of manufacturing our original drivers.

We must consider, just in the case of the tweeters, if a 25 cent fuse will blow protecting my $20 - $50.00+ tweeter, I see no problem fusing my tweeters with a fast blow fuse.

The woofer on the other hand, needs a slow blow fuse, I will stick my neck out and say that the FNM 8/10 amp fuse may be adequate for the woofer alone.

It would not hurt to reduce it to FNM 6/10 amp.

The cost of the slow blow fuses are considerably higher than the original 3 fuses for $1.00 parcel post paid.

You want probably at least two fuses in use, and 4 pairs as spares, in other words, 10 fuses on hand, of the slow blow, and likewise of the fast blows.

We won't condone disco levels, but for the higher level passages that do exceed the norm, fuses should be great.

>

>I went the route I did due to the classic Absolute Sound

>article from 1973 which states, "In fusing the Double

>Advent System, we ignored Advent’s recommendation and used AGC

>3s.

This size fast blow fuse does not protect the tweeters from damage.

At the very least each speaker cabinet should have been fused separately.

These fuses, used in conjunction with the Phase Linear

>700, do not blow until the speaker is being fed 60 watts rms

>steady loads (that represents zero on Phase Linear’s averaging

>meters). Any sudden transient through the system (a dropped

>tone arm, a faulty switch) will blow the fuses and protect the

>Advents. With the Phase Linear 700 and the Double Advent

>System, you seldom have to worry about hitting the “zero”

>meter reading mark; few records will even push the Phase

>Linear meters past the “minus 20 kdB” point".

This

>article does not say how the stacked double Advents are hooked

>up (series or parallel, but most likely in parallel)

They were in parallel to load the amps with a 4 ohm load.

to the

>Phase Linear 700 or how they connected the fuses. I just

>assumed that one fuse per positive speaker lead (8 Ohm

>designation) would do the trick. Without knowing the

>electronics behind it I am hoping that each speaker will not

>be fed much over 60 watts RMS from the 200 watts RMS channel

>of the Phase Linear 400 before a fuse will blow.

>

>Whadaya think?

Hi there;

I am going to also suggest that you goto the, "other forum", to Nov/06 I believe, "fast blow fuses" and follow all of the threads, if you haven't already done so.

Good luck.

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Always remember that we own hifi not disco speakers.

They were never meant to be driven at disco sound level's.

I never meant that I listen to music at disco levels, but am leary of peaks damaging the speakers when listening to fairly loud music. I doubt I ever listen to music much over 90 dB.

This was the size fuses they wrote that they used in that

review.

That was many decades ago.

Now we need to look at fusing from a different perspective.

A very kind member downloaded Advent fusing information to our

site.

They recommended the same size slow blow fuse for The Smaller

and The Larger Advents.

Buss FNM 8/10 amp slow blow fuse, or, of the FLM slow blow

Littlefuse brand, if I remember correctly was the fuse that

Advent recommended, THEN.

With this particular fuse, it offers very little protection to

the tweeters.

If I could experiment, I would quite likely use a downsized

FNM-6/10 fuse for the woofer and a 3/4 or 1 amp, in that range

at least, fast blow fuse for the tweeter.

Yes, this would require 2 external fuseholders, and the

related wiring mods, or even two chassis mount style

fuseholders.

So you are saying that a 3 amp AGC3 is insufficient to protect the tweeters? It is my understanding that it is the tweeters that need protection, not the woofers, and if the tweeters are protected from excessive power the woofer should be also. Perhaps, a different fuse amperage should be selected, say 2 or 1.5 amps, but I would think the AGC fast blow fuse would be adequate to protect the tweeters.

This is what James took a photo of last year, on his

speakers.

He did a very professional job of mounting the fuseholder and

the crimp type connectors.

He used an open style fuseholder, which also allows the fuse

to cool, and mounted it to the rear of his speaker.

This may be the better location or at the rear of the

amplifier, whichever is easier to get at when the fuses blow,

and also not short.

I could always leave the cover off the fuseholder if cooling becomes an issue.

I have a fuse holder mounted on the back of each speaker near the input leads.

Many moons ago there was controversy regarding fusing and the

effects of the damping factor.

The fuse is actually a small inline resistance which does

affect the damping factor.

But, to be realistic today, decades after our manufacturers

have gone out of manufacturing our original drivers.

We must consider, just in the case of the tweeters, if a 25

cent fuse will blow protecting my $20 - $50.00+ tweeter, I see

no problem fusing my tweeters with a fast blow fuse.

The woofer on the other hand, needs a slow blow fuse, I will

stick my neck out and say that the FNM 8/10 amp fuse may be

adequate for the woofer alone.

It would not hurt to reduce it to FNM 6/10 amp.

The cost of the slow blow fuses are considerably higher than

the original 3 fuses for $1.00 parcel post paid.

You want probably at least two fuses in use, and 4 pairs as

spares, in other words, 10 fuses on hand, of the slow blow,

and likewise of the fast blows.

We won't condone disco levels, but for the higher level

passages that do exceed the norm, fuses should be great.

Again, why worry about the woofer if the tweeter is protected and anything that would trip the fuse to protect the tweeter would not harm the woofer anyways. Please forget about disco levels, that's not what we are talking about here. But we are about the higher level

passages that do exceed the norm.

This size fast blow fuse does not protect the tweeters from

damage.

So would a AGC2 or AGC1.5 fast blow fuse be adequate?

At the very least each speaker cabinet should have been fused

separately.

They are, each with a Philmore H108A and a AGC3. If the AGC3 is inadequate, is there a AGC fast blow fuse that is?

They were in parallel to load the amps with a 4 ohm load.

That is my understanding from what I have read. Does that mean under the 1973 Absolute Sound scenario each speaker could receive at least as much power as I am using, 200 watts RMS per speaker at 8 Ohms? They were using one AGC3 for two speakers in parallel at 4 Ohms with the Phase Linear 700, what about 600 watts RMS into 4 Ohms? Does that equate to 300 watts RMS per speaker? I guess I don't know the relationship there. But it would seem a PL 700 could potentially be delivering more power to stacked double Advents in parallel at 4 Ohms than two PL400s with a separate channel at 8 Ohms for each speaker.

Hi there;

I am going to also suggest that you goto the, "other

forum", to Nov/06 I believe, "fast blow fuses"

and follow all of the threads, if you haven't already done

so.

Good luck.

And the "other forum" is which?

Thank you for your help. Just trying to sort it out.

Edited: I see the "Other" forum now and will research further there. Thanks!

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>Always remember that we own hifi not disco speakers.

>

>They were never meant to be driven at disco sound level's.

>

>

>I never meant that I listen to music at disco levels, but am

>leary of peaks damaging the speakers when listening to fairly

>loud music. I doubt I ever listen to music much over 90 dB.

Disco levels or just plain loud, 90db is loud.

Every member here will have their own idea how loud, loud is.

>This was the size fuses they wrote that they used in that

>review.

>

>That was many decades ago.

>

>Now we need to look at fusing from a different perspective.

>

>A very kind member downloaded Advent fusing information to

>our

>site.

>

>They recommended the same size slow blow fuse for The Smaller

>and The Larger Advents.

>

>Buss FNM 8/10 amp slow blow fuse, or, of the FLM slow blow

>Littlefuse brand, if I remember correctly was the fuse that

>Advent recommended, THEN.

>

>With this particular fuse, it offers very little protection

>to

>the tweeters.

>

>If I could experiment, I would quite likely use a downsized

>FNM-6/10 fuse for the woofer and a 3/4 or 1 amp, in that

>range

>at least, fast blow fuse for the tweeter.

>

>Yes, this would require 2 external fuseholders, and the

>related wiring mods, or even two chassis mount style

>fuseholders.

The usual fuseholders are clips with no cover.

There is also chassis type which are round and only the screw cap is exposed to the user.

The heat of the fuse can build up inside that type and blow at a lower rating.

Heathkit used one in one of their models and even included an o-ring to seal the screw cap.

>So you are saying that a 3 amp AGC3 is insufficient to protect

>the tweeters?

Yes

It is my understanding that it is the tweeters

>that need protection, not the woofers, and if the tweeters are

>protected from excessive power the woofer should be also.

They both need protection, the woofers suffer mostly from thermal damage and the tweeters from transient overloads.

That is why the more expensive but best route to go is slow blow for the woofers and fast blow for the tweeters.

The fast blow are not the special extra fast ones often used in test meters, these would likely blow way too soon.

>Perhaps, a different fuse amperage should be selected, say 2

>or 1.5 amps, but I would think the AGC fast blow fuse would be

>adequate to protect the tweeters.

Re-read this all over again.

>This is what James took a photo of last year, on his

>speakers.

>

>He did a very professional job of mounting the fuseholder and

>the crimp type connectors.

>

>He used an open style fuseholder, which also allows the fuse

>to cool, and mounted it to the rear of his speaker.

>

>This may be the better location or at the rear of the

>amplifier, whichever is easier to get at when the fuses blow,

>and also not short.

>

>I could always leave the cover off the fuseholder if cooling

>becomes an issue.

I would not have any covers over the glass type fuses, they are probably illegal for typical use, and it retains the heat.

>I have a fuse holder mounted on the back of each speaker near

>the input leads.

>

>Many moons ago there was controversy regarding fusing and

>the

>effects of the damping factor.

>

>The fuse is actually a small inline resistance which does

>affect the damping factor.

>

>But, to be realistic today, decades after our manufacturers

>have gone out of manufacturing our original drivers.

>

>We must consider, just in the case of the tweeters, if a 25

>cent fuse will blow protecting my $20 - $50.00+ tweeter, I

>see

>no problem fusing my tweeters with a fast blow fuse.

>

>The woofer on the other hand, needs a slow blow fuse, I will

>stick my neck out and say that the FNM 8/10 amp fuse may be

>adequate for the woofer alone.

>

>It would not hurt to reduce it to FNM 6/10 amp.

>

>The cost of the slow blow fuses are considerably higher than

>the original 3 fuses for $1.00 parcel post paid.

>

>You want probably at least two fuses in use, and 4 pairs as

>spares, in other words, 10 fuses on hand, of the slow blow,

>and likewise of the fast blows.

>

>We won't condone disco levels, but for the higher level

>passages that do exceed the norm, fuses should be great.

>

>

>Again, why worry about the woofer if the tweeter is protected

>and anything that would trip the fuse to protect the tweeter

>would not harm the woofer anyways. Please forget about disco

>levels, that's not what we are talking about here. But we are

>about the higher level

>passages that do exceed the norm.

>

>This size fast blow fuse does not protect the tweeters

>from

>damage.

>

>So would a AGC2 or AGC1.5 fast blow fuse be adequate?

You're on your own with that one.

>At the very least each speaker cabinet should have been

>fused

>separately.

>

>They are, each with a Philmore H108A and a AGC3. If the AGC3

>is inadequate, is there a AGC fast blow fuse that is?

>

>They were in parallel to load the amps with a 4 ohm

>load.

>

>That is my understanding from what I have read. Does that

>mean under the 1973 Absolute Sound scenario each speaker could

>receive at least as much power as I am using, 200 watts RMS

>per speaker at 8 Ohms? They were using one AGC3 for two

>speakers in parallel at 4 Ohms with the Phase Linear 700, what

>about 600 watts RMS into 4 Ohms? Does that equate to 300

>watts RMS per speaker? I guess I don't know the relationship

>there. But it would seem a PL 700 could potentially be

>delivering more power to stacked double Advents in parallel at

>4 Ohms than two PL400s with a separate channel at 8 Ohms for

>each speaker.

>

>Hi there;

>

>I am going to also suggest that you goto the, "other

>forum", to Nov/06 I believe, "fast blow fuses"

>and follow all of the threads, if you haven't already done

>so.

>

>Good luck.

>

>And the "other forum" is which?

>

>Thank you for your help. Just trying to sort it out.

>

>Edited: I see the "Other" forum now and will

>research further there. Thanks!

A point of interest from the Absolute Sound review.

There was a comment on how many tweeters they went through because they weren't protected with the screens.

Unless one was moving them all around and puting their fingers all over that particular area, and pushing them in, the tweeters should not have been touched or damaged.

Because my servicing never included the Larger Advent's, I do not know the Achilles heel of that speaker system, be it the woofers or the tweeters.

I can't even make a guess.

I do know, the Dynaco A-25's was their woofer, with a few hundred dead ones replaced, and zero tweeters.

The AR-LST's weakness was their tweeters, oodles and oodles.

I always wondered why they did not engineer in the extra fuseholders, instead of just the one for the system.

I do hope you went to the Crown site.

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Guest One-Shot Scot

>Hi there;

>

>Unfortunately, I have yet to find an article regarding an

>Advent recommended fast or slow blow fuse for the Larger

>Advent.

>

>I am sure there was one and maybe a new member may have a copy

>they can download to our site for our future referrence.

This information is taken directly from the Advent brochure entitled, "Using the New Advent Loudspeaker", which was packed in the boxes containing my New Advent Loudspeakers which I purchased in 1978. This information may or may not apply the original Advent Loudspeaker.

POWER HANDLING

As with any product, the New Advent Loudspeaker has operating limits, and consistently exceeding those limits will damage the speaker. Fortunately, there is an audible warning when those limits are approached: distortion, such as "fuzzy" or "gritty" sound, which is usually the result of driving an amplifier beyond it's undistorted power capability. Overdriving an amplifier or receiver -- including one with a modest power rating -- in turn overdrives the speaker so that permanent damage results. Should you encounter the warning of distortion at loud volume levels, no harm will be done if you immediately turn down the volume to a point where the distortion disappears. However, prolonged operation at distorted volume levels can damage the speaker system, and such damage is not covered by the warranty.

FUSING THE SPEAKER

To help protect against such damage, the speaker may be fused with a one-amp, slow-blow fuse inserted in either of the two leads connecting the speaker to the amplifier, as illustrated.* This type of fuse will blow if sustained power sufficient to damage the speaker is present, but usually will not interfere with instantaneous musical peaks: it will pass 400 watts for one second, 25 watts for 30 seconds and 12 watts continuously. However, it will not protect the speaker from sudden non-musical transients, so keep volume low when changing records or FM stations. The correct fuse designations are MDL-1, 3AG 1 amp Slo-blo, or FNM-1; they are readily available under such brand names as Littlefuse and Fusetron. If you have any difficulty obtaining fuses and holders locally, write Advent's Customer Relations Department for information on ordering them from the factory.

* The illustration shows a cylindrical glass fuse in a holder which has been inserted in the wire connecting the negative terminal of the amplifier to the negative connector labeled "0" on the back of the New Advent Loudspeaker. The notation above the fuse holder reads, "Fuse holder may be located anywhere along speaker line.

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>>Hi there;

>>

>>Unfortunately, I have yet to find an article regarding an

>>Advent recommended fast or slow blow fuse for the Larger

>>Advent.

>>

>>I am sure there was one and maybe a new member may have a

>copy

>>they can download to our site for our future referrence.

>

>

>This information is taken directly from the Advent brochure

>entitled, "Using the New Advent Loudspeaker", which

>was packed in the boxes containing my New Advent Loudspeakers

>which I purchased in 1978. This information may or may not

>apply the original Advent Loudspeaker.

>

>POWER HANDLING

>

>As with any product, the New Advent Loudspeaker has operating

>limits, and consistently exceeding those limits will damage

>the speaker. Fortunately, there is an audible warning when

>those limits are approached:

After seeing hundreds of burnt voice coils and slightly burnt voice coils, I can vouch that you will hear distortion, but by then it is usually too late.

Don't let anyone tell you that it is either burnt or not, there is in between while it is in transition.

Voice coils can generate and pump 150 deg cel air out of their woofer dust covers.

Dynaco woofers voice coils were sometimes coated with a bad batch of varnish or whatever.

They would bubble when heated and the bubbles would touch the housing in the gap and sound like a faint buzz when they were small.

The larger the bubble became the louder the buzz.

With my knowledge, I would attempt to repair them, but for most everyone it is a goner, there may be a few members that may be successful repairing them as well.

distortion, such as

>"fuzzy" or "gritty" sound, which is

>usually the result of driving an amplifier beyond it's

>undistorted power capability.

Overdriving an amplifier or

>receiver -- including one with a modest power rating -- in

>turn overdrives the speaker so that permanent damage results.

Should you encounter the warning of distortion at loud volume

>levels, no harm will be done if you immediately turn down the

>volume to a point where the distortion disappears.

Sure, if you are, The Flash.

However,

>prolonged operation at distorted volume levels can damage the

>speaker system, and such damage is not covered by the

>warranty.

>

>FUSING THE SPEAKER

>

>To help protect against such damage, the speaker may be fused

>with a one-amp,

This was changed to FNM 8/10 amp at some point in time, but now it may be, that we are talking of two different Advents.

slow-blow fuse inserted in either of the two

>leads connecting the speaker to the amplifier, as

>illustrated.* This type of fuse will blow if sustained power

>sufficient to damage the speaker is present, but usually will

>not interfere with instantaneous musical peaks:

it will pass

>400 watts for one second, 25 watts for 30 seconds and 12 watts

>continuously.

These numbers should not have been published as they leave the wrong impression of what a hifi speaker is to be used for.

However, it will not protect the speaker from

>sudden non-musical transients, so keep volume low when

>changing records or FM stations. The correct fuse designations

>are MDL-1, 3AG 1 amp Slo-blo, or FNM-1; they are readily

>available under such brand names as Littlefuse and Fusetron.

>If you have any difficulty obtaining fuses and holders

>locally, write Advent's Customer Relations Department for

>information on ordering them from the factory.

>

>* The illustration shows a cylindrical glass fuse in a holder

>which has been inserted in the wire connecting the negative

>terminal of the amplifier to the negative connector labeled

>"0" on the back of the New Advent Loudspeaker.

I have never read anything regarding whether the plus or minus is or is not recommended, even though we can consider one lead hot and one ground.

From my background, I would suggest the plus or hot lead, as opposed to the minus or ground leads.

Another consideration is where to place or mount the fuseholders.

The speakers may be at their most accessible location, with them being screwed to the rear of the enclosure.

Another issue that I have never discused before is, if the speaker leads are shorted between the amp and the fuses the amplifiers circuits may be damaged.

There was an example of that when cables were run under a bed frame, as per W. Marshall Leach Jr.

In my own case, I had run the wires under our bed chesterfield and carpet and when we sat down, they shorted.

A trip down to the service shop was necessary, as they were internal amplifier fuses.

The

>notation above the fuse holder reads, "Fuse holder may be

>located anywhere along speaker line.

>

>

Hi there;

Thank you for this information.

Are you able to download the booklet here, please?

The original Large Advent did not have any fusing recommendation at all, initially.

The Smaller Advent had it's recommended fuse size published and the fuses and fuse holders were available direct from Advent at a very reasonable price.

AR sold their fuses and holders to customers at their cost.

Somewhere in time there was a letter or statement, that they used the same fuse size, even though The Larger Advent was 8 ohms and The Smaller Advent was 4 ohms.

With the end of production of, The Larger Advent, and newly introduced The New Advent, I assume, they felt it was time to address the fusing.

This topic would have been better in the, "Other Forum", under the Fast Blow Fuses topic, for continuity of information.

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