AR-6 crossover

[grish]

Hello From Maisons-Laffitte; near Paris, France.

I've found two blond AR6 this WE. SN 39801- 39777.  Once undress... here are  the pics. I need your expert advices.

For the woofer do I need to replace the two component behind ? 

And for the crossover Is replacing the blue cap enough ? what do I need to buy ?

The tweeter seems to be a little shy. Do you think this one can respect the original design ?

https://www.simplyspeakers.com/replacement-speaker-tweeter-t-135.html

Thank you for youre help. I promised dress pics when i'll finished to oil the box. 

The sound, despite the current shape, is astonishing. I 'm curious to hear the voice as is has been design.

Grish

KEF C25, C75, Martin Logan Script, JBL HP580

 

 

[ra.ra]

Bonjour and bienvenue, Grish. All of the components in your AR-6's appear totally original, and included here is the schematic of your speaker circuitry. I will suggest that those speakers are fully restorable, but do go slowly with the project and don't try to overwork any step of the process.

The tweeter you have provided in the link is not a good idea for this speaker. Although it is a decent tweeter and it has often been used as a replacement in the AR-4x, it will not fit the cabinet holes and prep of your current tweeter. Your tweeters are originals, and if they are both functional, should be re-used in your re-build project. Your comment about them being "shy" is curious, however, because this is normally a tweeter that has a pretty substantial personality, or presence, in my opinion. The other components in the tweeter circuit are also original and normally stable. I cannot read the resistor values, but they appear identical to 3 ohm resistors I've found in a similar AR-6, and the blue can 10uF cap is also very familiar. Typically, these caps are often very stable even 45 years later, but it is possible that this cap value has drifted and might benefit from replacement. The three-position switch is also usually trouble-free, but perhaps some electronic circuit cleaner can be sprayed into the switch from the backside.  You should hear some difference in tweeter output between the various switch settings.

I am unfamiliar with parts suppliers in Europe, but these might be good places to begin shopping.

http://www.falconacoustics.co.uk/alcap-claritycap-solen-audio-capacitors.html

http://www.mundorf.com/english 1.1/handelliste/fachhandel/Revendeurs.pdf

Regarding the woofers, you will obviously need to locate, order, and install new foam suspension surrounds. The green component attached should be a 10 ohm resistor and should not require replacement. The larger silver can is a 24uF capacitor and probably should be replaced, although this value is often difficult to locate.

And the cabinets, which you have mentioned are "blonde". Please provide some pics of these (grilles, too!). If your cabinets are unfinished pine, as I suspect, an oiled finish might not be your best choice, so my advice is to proceed slowly. 

[grish]

Thank you for your detailed answer.

So I will give a try to the circuit cleaner tricks. I've already order https://www.simplyspeakers.com/acoustic-research-speaker-foam-edge-repair-kit-fsk-8.html

never done that before. any advice are welcome :-)

The larger silver can 24uF capacitor will be replaced.

For the cabinet I though it has dry, but it's perhaps his natural state. Seem's to be birch.

[JKent]

Bienvenue Grish

If you have never done a foam job before, I would advise that you NOT use the glue that comes with the Simply Speakers kit. It is solvent based and very unforgiving. You can use Aleene's Tacky Glue https://www.amazon.fr/Aleenes-Tacky-Colle-usage-Royaume/dp/B00178KLEY/ref=sr_1_1?ie=UTF8&qid=1508193112&sr=8-1&keywords=aleene's+tacky+glue

The Tacky Glue is white, water-based and dries clear. If you make a mistake you can wash it off. You can spread it around with a finger if you want. Clean off any excess with water. If you don't align the foam correctly just pull it apart (before it dries). Some re-foam kits come with white PVA glue, which is virtually identical to Aleene's.

Those cabinets may be birch. Don't know what the green stains are but maybe you can get them off with lacquer thinner or maybe very light and careful sanding. 

-Kent

[ra.ra]

Thanks for those pics - - - the grilles and badges look terrific, and.... WOW... those cabinets have huge potential. I have never seen a veneer like that on AR speakers and it definitely does not resemble the Ponderosa pine found on U.S. "blondies". Thinking about the Euro market, to my eye the grain looks too tight and linear to be birch, but also too light to be teak ..... could it possibly be beech?  

Very nice speakers you've got there - - after clean-up, they just might look best with an oil finish. Check out the falcon acoustics link - - just trying to save you from unnecessary  international shipping charges.

[ra.ra]

On October 16, 2017 at 4:46 PM, grish said:

never done that before. any advice are welcome :-)

Are you saying you need some assistance with your first re-foam project? Regarding glue type, I would agree with JKent that a good quality water-based white hobby glue should work best - - - it sets up slowly and gives the installer some necessary time to ensure that parts are properly aligned and bonded.    

Just one other thought - - I would expect that your woofers have these two rings shown in this first pic. If so, be sure to leave in place the outer "basket ring" when you begin to re-foam the woofers - - you need to glue the new surround to this surface. Also attached are 'before' and 'after' pics of my restored pair which is the same version of AR-6 that you have.  

[grish]

Thank's a lot for all this good advices, the good glue will help me.

I would expect that your woofers have these two rings shown in this first pic. If so, be sure to leave in place the outer "basket ring"

What if some come new with the kit ? can I keep the old one ?

I will search more for tutos on youtube. First, foam and cone, and secondly, foam an metallic circle.

I've understood that the sound design require a tight seal. I hope that will balance the tweeter .

[ra.ra]

4 hours ago, grish said:

What if some come new with the kit ? can I keep the old one ?

Not quite sure how to respond to this question yet. Maybe you can show us a pic of your woofer after it has been cleaned and ready for re-foam, and after you've received your repair kit.

YouTube tutorials can be very helpful to give you added confidence, but feel free to ask questions as they arise. The biggest issue that is forever debated with a typical re-foam project was first penned by William Shakespeare: "To shim, or not to shim, that is the question." Pic attached shows an AR-6 woofer with a new foam being loose-fit to the speaker cone after the dust cap has been cut (and removed) and is sitting atop the clear plastic shims that have been installed. When possible, I like to re-use the original dust caps after the shims are removed.

 "First, foam and cone, and secondly, foam and metallic circle."  Yes, this is the correct sequence.

".....the sound design require a tight seal."  Yes, this is also correct, and your woofers may require new material to seal them properly, but this is an easy step.

"I hope that will balance the tweeter." Airtight assembly is important, but this should not have significant effect on tweeter output. Are you planning to replace the original blue capacitors?

[grish]

Ok for changing the Blue crossover cap. can I mesure something ? What do I need to buy ? 

What is the interest to change the dust cap ? for me it's like cutting in an eye 

Can I do it after a "refoaming" ? or is it a step to do before ?

do I need to shim if I don't recap ? 

[grish]

Ok for changing the Blue crossover cap. can I mesure something ? What do I need to buy ? 

What is the interest to change the dust cap ? for me it's like cutting in an eye 

Can I do it after a "refoaming" ? or is it a step to do before ?

do I need to shim if I don't recap ? 

Work in progress, The two speakers are now operational and in break in. I haven't buy the electronic parts for the moment. The balance between the woofer and the tweeter is now totally different because the woofer evolve with the contraints of the air pression and depression limits. I've even set the tweeter to normal. The contract cleaner tricks has certainly help. They go deeper but never buzz.

[JKent]

On 10/22/2017 at 4:58 AM, grish said:

What is the interest to change the dust cap ? . . . Can I do it after a "refoaming" ? or is it a step to do before ?

The point of replacing the dust cap is to allow you to shim the voice coil during the refoam process. It keeps everything centered and allows you to raise and lower the cone while working on it. Since you have done the refoam job already, leave the dust cap alone and hope nothing rubs.

By the way, we usually say "re-cap" to mean replace the capacitors (not the dust cap). And if you do decide to re-cap you'll want to consider Solen capacitors. Very good quality, fabriqué en France.

For the 10uF capacitor use a film cap. Solen makes metalized polypropylene (that’s what we usually use here) but also Film & Foil Teflon, Metalized Teflon, Foil & Teflon, and Polyester. 

For the 24uF you can use foil if you wish but non-polarized electrolytic caps are fine and much less expensive. If you can’t find 24uF, 25uF is fine or you can put 2 caps in parallel to make the correct value. For example, two 12uF caps = 24uF. Don’t worry about the voltage rating on any of the capacitors—as long as they are 50 VDC or greater.

-Kent

[meta_noia_fot]

Hi everyone.

This thread has been an incredible resource for me so far. I was lucky enough to pick up a free pair of AR-6s from a local couple. The only other minor speaker restoration I've done in the past was refoaming a pair of Advent Legacy 1s, so the work on this project is much more significant...I could use some help.

All of the parts present appear to be original. I have taken a picture of the insides...it appears that I have a US Crossover A configuration (yellow fiberglass not pictured) with the early alnico woofers. One of the woofer stamps (pictured) shows a date of Jul 19 1971.

I am performing many of the recommended procedures suggested by this thread and others (replacing the capacitors, cleaning the pots, refoam, etc.), but need some advice on the woofer. As pictured, you can see that one wire connected to the cone is severed midway up. What would be the best way to fix this?

Keep in mind, this is my first lengthy speaker restoration. I'm relatively handy (used to repair woodwind instruments for a decade), but audio electronics are new to me. Any advice would be greatly appreciated.

-George

[Aadams]

Nice catch.  That appears to be the early long throw woofer. Be careful, they are rare and practically irreplaceable. 

[Aadams]

4 hours ago, meta_noia_fot said:

As pictured, you can see that one wire connected to the cone is severed midway up. What would be the best way to fix this?

Don't reconnect the broken wire by simply soldering because it will reduce the mobility of the connection between terminal and cone.   Wait for expert advice on how to handle.   Even with the broken wire you should be able to use a D cell battery to test if the speaker coil has continuity and moves freely.  If it checks ok, you can go to the trouble of repairing the wire.

[meta_noia_fot]

3 hours ago, Aadams said:

Don't reconnect the broken wire by simply soldering because it will reduce the mobility of the connection between terminal and cone.   Wait for expert advice on how to handle. 

That was my thought too and has me scratching my head. I'm trying to do this restoration the right way, so I'm taking everything slow and trying to do my research correctly.

[ar_pro]

The tinsel doesn't appear to have been snagged, or otherwise pulled away from the cone, but instead clipped. I wonder why someone would just cut it like that...what could have been the reason?

It should be simple enough to solder a slight additional length of tinsel to what's still attached to the cone, remove the remaining tinsel from the solder post, and then solder in the replacement. As Adams mentioned, it's important to avoid having too short a length of tinsel that could restrict cone movement.

The AR-6 is a nice speaker - do you have any photos?

[meta_noia_fot]

2 hours ago, ar_pro said:

The tinsel doesn't appear to have been snagged, or otherwise pulled away from the cone, but instead clipped. I wonder why someone would just cut it like that...what could have been the reason?

Inexperience possibly. I think the guy I got them from may have opened them up initially. He told me the "cones" needed work (I assumed he meant surrounds) but that the capacitor was good. The capacitors were the old wax block kind, and with this snipped tinsel, I'm assuming maybe he didn't know what he was talking about.

Still, no complaints from me. It's all original parts and has apparently been sitting in storage since the mid-90s.

2 hours ago, ar_pro said:

The AR-6 is a nice speaker - do you have any photos?

I forgot to take 'before' photos. It seems people on here like seeing process photos, so I'll take some as I work on them and post them here. I've never heard classic ARs but I'm excited from everything I've read. Currently using AR5 Hi Res speakers from 2000 or so. Very nice speakers but I'm looking forward to the vintage equipment.

[RoyC]

I've increasingly been seeing compromised tinsel lead due to wear at the cone or woofer terminals, but this would be the first I have seen in the middle...weird. It almost looks like it was cut. 🤔

The best repair is to dissolve the adhesive at the cone, de-solder the voice coil leads at the juncture, and reconnect/solder new tinsel lead accordingly. I've done a number of these repairs of late.

Roy

[meta_noia_fot]

I finally have some time to work on these this week now that some parts have come in. Thanks for weighing in. I think I am going to try to do the repair you suggested, @RoyC. What would you recommend using to dissolve the adhesive that is safe for the cone? And what adhesive would you use when gluing them back down again?

Thanks

[RoyC]

6 hours ago, meta_noia_fot said:

I finally have some time to work on these this week now that some parts have come in. Thanks for weighing in. I think I am going to try to do the repair you suggested, @RoyC. What would you recommend using to dissolve the adhesive that is safe for the cone? And what adhesive would you use when gluing them back down again?

Thanks

I (sparingly) use toluene to remove the old adhesive. Madisound sells "neoprene seal cement", which works well to glue them back down. It is toluene soluble as well. https://www.madisoundspeakerstore.com/adhesive/seal-cement-2fl-oz/

Roy

[meta_noia_fot]

Thanks @RoyC. I'll post updates once I have them.

[meta_noia_fot]

Finally got to work on the AR-6s this week.

First, the good news. I got one speaker completely reassembled and working. Capacitor and surrounds replaced, pots cleaned. I spliced in some extra wire to make reassembly and service easier in the future. And of course I replaced the cut tinsel wire on the woofer. I was able to play test some music in mono mode on my amp and I'm really impressed with the sound on the single AR-6.

As for the bad news. The tweeter on speaker number 2 didn't work after reassembly (and I didn't test before disassembly). I discovered that the tinsel wire connecting the tweeter is severed. After pulling back the duct tape (and making the problem slightly worse), there is about a 1/2" wire missing.

Is it possible to save this tweeter by rewiring it? Should I attempt to source an original replacement woofer instead?

-George

 

 

[RoyC]

Nice job on the woofer.

It is delicate work, but if you are able to clean the broken lead from the tweeter cone (MEK will dissolve the enamel coating), it is possible to extend it with a single strand of tinned wire. It does not have to be tinsel lead, but you will need an extremely steady soldering hand!

Roy

[meta_noia_fot]

Thanks @RoyC. I'll give it a go this weekend. Fingers crossed this will be the last work I need before the pair is functioning.

[meta_noia_fot]

Well after family left following Thanksgiving, I got back on the AR-6s. After a couple hours, I was able to resolve the remaining issues with the electronics. (I still can't fathom that I got the voice coil lead soldered to a single strand.) They sound terrific and today is mostly going to be me enjoying these.

There are still some lingering issues--for instance, the old foam gaskets aren't sealing well and need to be replaced--but nothing that prevents them from functioning. I'll slowly work on resolving these issues and later the grills/badges (which are just about toast as you can see in the pics below). Please excuse the rudimentary wedges but I don't have any real stands (or bookshelves) in my listening room. Thanks again for all your help @RoyC.