AR 5 restoration

[Luxman]

Good morning,

Since I am new here I'd like to introduce myself. I am from holland and I am a collector of classic audio from the seventies.

Through the past decades a lot of different brands have come across my collection. At the moment I use a Luxman L505V Amp with different loudspeaker sets like the Elipson 1303, Translator Impact 5 AND Kef Cadenza.

Last summer at a yard sale I came across a set of Acoustic Research AR4xa speakers. Thought I'd restore them and sell them on.

I refoamed the woofers and placed a new cap. Original it came with a 6uf cap but because a 5.6uf was easier to come by I placed this one.

When they were finished I was impressed of the sound quality of this speakers and now they took place next to my other systems.

Several years ago I already bought a set of AR5 speakers witch are in a poor state, the cabinets were painted white and one of the tweeters do not work.

after my experience with the AR4's I now am very curious about the AR5's so I decided to restore them.

I stripped the white paint of the cabinets and removed the Fiberglass. Ordered new foam for the woofers and looked at the crossovers. Somebody had already switched out the pots but luckily they are still there. 

 

  

[Luxman]

Unfortunately after removing the white paint a lot of white remains in the wood grain. I don't think I can easily remove this so I think I will paint the cabinets black.

Opened the pots and they can still be saved

  

[Aadams]

Luxman

Welcome.  AR5s are among the very best ARs. Are you looking for information or telling us what you intend to do?

Adams

 

[Luxman]

I actually wanted to share the progress in my restoration and maybe someone who is reading it can help on some difficulties.

For example if there is a possibility to clean the white paint out of the cabinet (I would like to keep the original brown colour) and I also would like to know if the original tweeters can be repaired.

I have already found companies who can repair the tweeters but I really would like to do it myself to learn something fromit   

[lance G]

Hi Luxman. How did you initially strip the speakers ? Did you use a liquid paint stripper ?

[Aadams]

1 hour ago, Luxman said:

For example if there is a possibility to clean the white paint out of the cabinet (I would like to keep the original brown colour) and I also would like to know if the original tweeters can be repaired. 

I have already found companies who can repair the tweeters but I really would like to do it myself to learn something fromit   

White paint has been removed from cabs but I don't remember it being removed from walnut veneer.  I do remember it involves a lot of water, oxylic acid and time consuming hand work.  Those with better knowledge will be along later.

The AR5 and AR3a are very similar.  If you have not read the AR3a restoration guide now would be the time to do that, before you get deeper into the project. 

Regarding pots and tweeters:

Over the 20 year life of this forum the opinion regarding pot repair has changed.  Almost everyone who has fought pots now believes it is almost never worth the effort to restore pots when it is so much easier in the long run to install Lpads and resistors.  LPads give you better control, are trouble free and inexpensive.  There is also a new style pot available on ebay that is more expensive than lpads.

It is true your tweeter can be repaired by anyone who knows how to install a voice coil and new dome but it will not perform correctly at the crossover point when reinstalled.  The only two people in the world that we know of, who have the knowledge and proprietary materials to restore your tweeter to original performance are @RoyCand @Chris1this1.  Your alternative is a proven modification using a Hivi tweeter.

If you are particular about the woofer surrounds there are two correct choices. 

Adams

 

 

[Luxman]

How did you initially strip the speakers ? Did you use a liquid paint stripper?

I first tried it with a liquid stripper but since this did not remove all the white paint i did it with a hot air gun, this worked much faster but the result was the same.

Once I did a restoration on a set of translator Impact 5 speakers with the same problems. alse one of the cabinets had been painted white.

On a similar way I also removed the white paint and with a steel brush and a lot of sanding i managed to remove practicaly all of the white but the result was the soft wood grain was removed, only the hard grain left over which was good but not the way I should have wanted it.

This amount of work I would not like to do again, so if there is no more effective way I see no other possibility than painting themblack.

White paint has been removed from cabs but I don't remember it being removed from walnut veneer.

I understand my cabinets are walnut veneer?

 If you have not read the AR3a restoration guide now would be the time to do that, before you get deeper into the project. 

I have been reading a lot about repairing AR speakers on the internet, that is  how I came to this forum but this restoration guide is a good starting point, I wil start following this. thanks

There is also a new style pot available on ebay that is more expensive than lpads.

This is maybe a better solution because cleaning the first pot already took me some time and the result was not perfect yet.

Your alternative is a proven modification using a Hivi tweeter.

I have read about this tweeter too, this will probably be the solution I will follow. does this mean I have to change my crossover because this is a 6 Ohm tweeter?

I was thinking about replacing the fiberglass for another type of filling, since the original filling is kind a dangerous when inhaling and itchy to work with.

Is there another fiber which can be used as a replacement?

 

 

 

 

 

 

[Aadams]

12 hours ago, Luxman said:

I have read about this tweeter too, this will probably be the solution I will follow. does this mean I have to change my crossover because this is a 6 Ohm tweeter?

You need the parallel coil on the tweeter.  Most have installed the coil on the back of the tweeter.  I think the current advice is no cap changes. 

12 hours ago, Luxman said:

I was thinking about replacing the fiberglass for another type of filling, since the original filling is kind a dangerous when inhaling and itchy to work with.

If you have original glass fiber chunks put the material in a plastic bag and set it aside to reuse.

Is there another fiber which can be used as a replacement?  Not without experimentation.  Fiberfill works if you can get the weight right but it is so much easier to reuse the original 16oz to 18oz of fiberglass.  If you have rockwool in the boxes change to fiberglass.

Here is a recent thread that talks about the front wired mod for the Hivi tweeter,

Here is a very good AR5 restoration with Hivi

 

[lance G]

I appreciate the difficulty in removing the paint from the grain of the veneer, I suspect it may be water based paint that was originally applied ? Hence the difficulty in removal of same.

I have had some recent experience of the "new formula", allegedly improved paint strippers, probably better for the planet but not much good at properly stripping paint anymore. Resultantly I too have ended up resorting to the hot air gun, which can be a bit brutal on some finishes.

There may be a more expert wood finisher on the site with suggestions on how to soften the paint sufficiently to enable complete removal.

My ramblings aside, depending on how far you want to go, your abilities and what level of finish you would be happy to end up with, might you ultimately consider completely re-veneering the cabinets ? I have done so myself in the distant past, and recall it was not too onerous a task, with a highly satisfactory outcome.

[genek]

It appears that you still have paint haze on the surface and paint in the pores and grain. If you can dampen the surface with some mineral spirits and post a shot we can get a better idea of what you are dealing with.

Generally, the process is:

1. Apply stripper again. Scrub with a bristle brush rather than steel wool to try and get into the pores and grain.

2. Fill the pores and grain with tinted filler. You can get grain filler precolored for walnut, but you'll get better control of color by using plain filler and tinting it with stain. Use oil based products, not water-based. 

3. Apply sanding sealer

4. Stain. Use a pigmented oil-based stain rather than a dye or water-based stain.

5. Topcoat. You can't use a penetrating oil finish on filled, stained wood, so you'll need to apply lacquer, varnish or other clear coat. I'm not fond of poly, but a lot of people like it just fine.

[Luxman]

thanks everyone for the help for so far. tomorrow I will post a close up picture of the surface of the veneer.  I understand I have walnut veneer.

I've just looked at the restorations of the AR2 and the AR5. They surely look great and get a lot of information there. Thanks a lot !

Now one of my tweeters still works. is it possible to change just one of the tweeters or is it better to change both of them?

 

 

 

[genek]

Change them in pairs so the sound matches. Odds are that even the one that still works is not up to spec or will fail soon.

[ar_pro]

As Gene has advised, strip and fill the affected grain & pores; Minwax oil stains can then be mixed to achieve a near-perfect color match for the old AR oiled walnut finish.

Block-sanding with 400-600 grit paper should provide a nice smooth surface to receive the oil stain. 

I've seen a variety of sealers used to excellent effect, but I tend to prefer the protection that poly provides; with proper sanding & polishing, a well-applied poly finish can look just like oiled walnut. Avoid steel wool in favor of the 3M polishing pads.

On eBay, vintage-ar  sells replacement grille panels, cloth & badges that will make things look like new.

Since Chris and Roy offer excellent repairs of the AR-5 tweeters, it's now possible to keep your speakers in their original condition. The AR-5 is a very desirable & well-respected classic, and worthy of a careful restoration.

 

[Luxman]

I have taken some close up pictures of the veneer dampened with mineral spirit.

this is the underside of the cabinet. i'm planning to try and clean it with a liquid stripper to see what it does..

 

[genek]

Looks like you don't really have haze on the surface, just paint in the grain and scratches. Are those scratches only on the bottom panel, or are they on the sides and top as well?

[Luxman]

The scratches are only on the bottom side, the other sides look much better. the only problem is the paint in the grain.

Tomorrow i'm gonna try to remove it with liquid stripper and a copper brush. first on the bottom side, to see what it does..

[genek]

Wire brushes are probably not a good choice to use on veneer. You need something with finer, softer bristles, either natural or synthetic. You're trying to clean down into the grain, not scratch new lines into the wood. The brush needs to be softer than the wood. Try doing a small patch with an old toothbrush and see how that goes.

This is not something you can do in one easy pass. Doing it right will require making multiple passes on small areas with stripper and brush and then digging out some of the more stubborn bits of paint with tools like dental picks.

[Luxman]

At the moment i put the liquid stripper on the bottom of the cabinet to see what it does.. also I grabbed my wife's toothbrush for cleaning the veneer.

Not to worry about het missing it, I intend to put it back later without her noticing it😊

Another question about the tweeter, from a former project I still have 2 working AR tweeters from the AR19B speakers.

I just found out it is an 8 Ohm tweeter too.

Is there a possibility to use this one in the AR5 (Since this is an 8 Ohm also)?

[Aadams]

5 hours ago, Luxman said:

Is there a possibility to use this one in the AR5 (Since this is an 8 Ohm also)?

Will it connect and make noise?  Yes.

Will anyone here tell you to use it? No.

There was only one tweeter model made for the AR5 and it appears identical to an AR3a Classic tweeter but is not the same.  There are other AR tweeters that will exactly fit the hole but you will be experimenting with crossover modifications. Your mods may be spot on perfect for you but they will subtract value from the speakers and few if any here will be able to help you once you have cut your own path.

Regarding cost:  If DIY, in the U.S., the Hivi is the least expensive way to get close to the target.  Unless you get free parts, anything else will cost at least as much as getting your tweeters properly repaired.

Adams

[genek]

The AR-5 used the same tweeter as the 2ax. They're fairly common on eBay, but will still be old and probably out of spec. Either have yours rebuilt or use the HiVi alternative.

[Luxman]

In that case the HIVI is the best solution, I'd go for that. over here they are available for 30 euro a piece. so that's not that much.

Is it possible to buy the parallel coil in a webshop?

Today I have tried to make the cabinet look better, the liquid stripper did'nt do much. the white paint is in the small grains and these grains are about half a milimetre wide.

The only way to remove it is with a needle, that works but will take me hours. 

I repainted the front in black, that looks very nice, here are some pictures of the result:

 

[Luxman]

I also did some measurements on the capacitors. the original sprague compulytics are still in there.

the 24 uf gives 29.6

the 72 uf gives 73.3

the 72 uf is maybe still usable. is it sensible to reuse this one?

 

 

[Aadams]

32 minutes ago, Luxman said:

the 72 uf is maybe still usable. is it sensible to reuse this one?

I noticed the clamps and wasn't going to mention that there was probably no need to remove the Spragues. 

The Compulytics have proven to be durable.  Your meter may not be definitive in this case.   Our late member Carlspeak did a lot of testing on brands of old AR caps and concluded there was no need to change Sprague Compulytics.  I have 5s and 3as with Spragues and new NPEs.  You can't here the difference.

[Luxman]

ok, thats nice i can reuse the old ones. the 4uf is also the original one, does this mean i can leave this one there also?

[Aadams]

I you had not yet touched it I would say leave it but you are in deep now.  I think most here would advise you to replace the 4 with a new film cap.

Just in case you don't know;

Be careful with those mid range drivers.  They make the tweeter problem seem simple.