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Restoring my 3's


DavidDru

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Sounds like the mids are the weak point (other than the pots) in these aging speakers. Thank goodness someone like Roy is around to restore them if possible, but makes you wonder if the tweeters are really up to snuff even if you think they sound good.

I used that Duct seal on my Speakerlab 2's with good results. Whats the difference between it and the stuff vintageAR sells? (Boy those mids were kinda hard to get out that old stuff works so well.) I just took out my woofer on one of my KLH fives and they used a rather simple piece of thin foam that I am surprised worked well enough. Good thing though I used the acoustic speaker seal foam tape from Parts Express on these AR3's since I have had to go back in.

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Use the foam tape on the Fives too. Those foam gaskets were OK but after 50 years of compression they'll lack the sponginess you need.

-Kent

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Hi guys, and thank you for the kind words...

Below are just some rambling thoughts and opinions regarding some topics of conversation in this thread.

I'm with my pal Kent regarding the use of PE's foam tape. I use it whenever possible on woofers, and mids. It is a bit too thick for thinner plastic flanges (as found on many tweeters). Hardware department store "duct seal" works best on thin flanges and very rough surfaces, though I prefer the black sealant/putty sold by Parts Express. "Vintage AR's" AR putty is the same duct seal shown in the Home Depot link posted earlier in this thread, and can also be found in Lowes. He now uses PE gasket tape and PE sealant/putty, however, for his own restorations.

Many (perhaps most) AR-3's are now suffering from one or more of 3 significant issues having a direct impact on sound and functionality:

-degraded woofer glue

-stiffened midrange suspensions

-typical level control/pot corrosion.

Frankly, the easiest to install, most cost effective, and most reliable replacement controls to use are 15 watt 8 ohm L-pads sold by PE, Madisound, and Erse, among others. Vintage AR installs them in all of his restorations, and has sold many hundreds of these without issue. I recommend using a parallel 25 ohm resistor with the midrange to make the L-pad act like the original pot. Old AR tweeters can use all the help they can get, so there is no need to use the resistor with the tweeter control. If maximum re-sale value is of concern, however, the use of original, not Ohmites, etc, pots are more likely to bring about the desired outcome.

Due to the use of very reliable oil-filled caps in early AR-3's, not all 3's require cap replacement.

Relatively insignificant issues mentioned in this thread would be the need to re-seal the woofers' cloth surrounds (the large AR woofer seldom needs it), the type and implementation of zip ties used to secure caps (they all work just fine), and the use of crimps vs solder (I personally prefer solder and wire nuts). Goop brand glue can also be used to secure caps. It works better than hot glue if you have the time to let it dry.

For crossover wire I prefer tinned 18ga or 16ga copper wire, just like the original AR wire. It is available in the appropriate colors from sellers such as Parts Express and MCM Electronics as "hook-up" wire, and is also sold as "marine wire" from other online sources.

It has been theorized, but never proven, that AR stuffing causes the ubiquitous pot corrosion. I have seen the same Aetna-Pollack pot corrosion in all eras of AR speakers with both types of stuffing, as well as some other speaker brands equipped with A-E controls. I have also seen a number of AR's with original stuffing, which has had no apparent effect on rather old L-pad type replacement controls. With that said, the batts of stuffing used in the AR-3 and earliest versions of later AR models is very nasty stuff, and I routinely replace it (outdoors, wearing a dust mask). The later clumpy yellow fiberglass stuffing, introduced around 1970, however, is excellent and can easily be re-used.

The AR-3 tweeter sometimes suffers from one of two issues:

-stiffened voice coil gap coating reducing output. This is usually not as bad as the mid issue. Careful scraping and removal with something non-magnetic (like a toothpick or Exacto blade) can improve response if this is the case. If it sounds OK, leave it as is.

-"popped" dome...not an easy repair, if at all, depending on degree. Reduction or removal of the above mentioned coating could increase the chance of a "popped" dome, though I've never seen it happen as a result of the procedure. The orange suspension blobs of foam are much more important.

Anybody dealing with the AR-3 dome tweeter and mid must be aware of their fragile aluminum leads requiring special solder. AR's use of A-E pots, delicate aluminum wire for early voice coils, and apparent preoccupation with "foam everything" has proven to be a restoration challenge. Typical KLH specimens may have crappy caps, but are usually easier to restore closer to original specifications. Imo, KLH is still flying under the radar, provides excellent bang for the buck, and often provides more satisfying restoration results than AR.

Roy

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That's a really great update summary, Roy, and once again many thanks to you and many others for all the assistance and advice you all continue to offer for these various restoration efforts.

You're welcome, ra.ra...I've been doing this for so long it's people like you who help keep it interesting. Besides, we can't do much else with this crazy winter we're having here in the Northeast! I'm sure you agree, Boston. :)

Roy

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Roy, do you like the connector wire to be tinned because of the soldering benefits? I was reading about tinned vs non-tinned and apparently non-tinned is a better conductor (although probably nothing we would notice in our application because of the relatively low frequency of audio signal)

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Roy, do you like the connector wire to be tinned because of the soldering benefits? I was reading about tinned vs non-tinned and apparently non-tinned is a better conductor (although probably nothing we would notice in our application because of the relatively low frequency of audio signal)

Hey Dave,

That, and resistance to corrosion...which is why it is used in marine applications. There is absolutely no downside to using it in kind in crossovers. Significantly more tinned wire has been used in speaker crossovers (and computers) than not. Be careful, internet audio forum reading can be detrimental to sanity. :)

I should add that with a speaker like the AR-3 where two out of the three drivers are equipped with fragile, oxiidized, aluminum leads and voice coils, tinned vs bare copper wire can never be the subject of any serious discussion.

Roy

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Roy....I did the KLH thingy and found then to be a worthy speaker...in fact...the cabinet is really nicely done and the sound very nice. But I sold them......and kept the AR's. A personal choice I know but thru the AR speakers I have had and meeting you, I found out way more than I could ever have on my own on the science behind speakers. I just never knew what was involved and through your kind involvement, I became very attached to the AR sound. The sound, the history, and especially you have enabled me to have a collection of AR's that I love. You did tremendous work on finding a tweeter replacement for the 3a. What would be ideas on the 3 tweeter if it fails in the future and one wanted to keep it?

And I know I have personally made some entertainment for you with my crazy ways sometimes....:)

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Heck, a few years from now we will be able to use our 3D printers to fabricate all these unobtainium parts. Roy will be able to take it easy at that point.

Sanity? Heck I lost that a few months into this hobby. Proof is in the too many speakers I have around the house. Ask my wife. On second thought, no, don't ask my wife.

I just need to hurry up and finish cleaning up my Altec Valencias and Pioneer HPM-100's to sell off and all will be better. I know it will. (BTW, those are the only 2 sets of speakers I have purchased with the intent of flipping - to help pay for all the other stuff)

Lakecat, Of KLH, I am also in the midst of assessing my Model Fives for crossover improvement with the good doctor JKent providing some thoughts and wise input. Mine are in pretty darn good shape so there is no hurry. I just don't know if what I am hearing out of them now is as good as they get.

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Well, there is a nice pair of KLH Model 23's available out here in the unseasonably warm climes of western Nevada, $200. Tempting but need to put the money to work elsewhere :) I am leaning towards some 4x's in the 2-way department.

Roger

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DavidDru, on 16 Feb 2015 - 10:00 PM, said:

Heck, a few years from now we will be able to use our 3D printers to fabricate all these unobtainium parts. Roy will be able to take it easy at that point.

Sanity? Heck I lost that a few months into this hobby. Proof is in the too many speakers I have around the house. Ask my wife. On second thought, no, don't ask my wife.

I just need to hurry up and finish cleaning up my Altec Valencias and Pioneer HPM-100's to sell off and all will be better. I know it will. (BTW, those are the only 2 sets of speakers I have purchased with the intent of flipping - to help pay for all the other stuff)

Lakecat, Of KLH, I am also in the midst of assessing my Model Fives for crossover improvement with the good doctor JKent providing some thoughts and wise input. Mine are in pretty darn good shape so there is no hurry. I just don't know if what I am hearing out of them now is as good as they get.

Hi David.....sorry to hear about your mid. Even if you find a replacement, it may be on a short history list and one will pay big for it. I already have later model replacements for mine in case.

The KLH won't come alive until all updating is done...and Kent is excellent help for those. THey were made to take on the mighty 3a so sound is close and some prefer it over the 3a. I learned the weak link on those is the leads on tweeter if I remember correctly...but fixable. I really liked them but me heart is in the AR's I guess...... but certainly get the 5's much cheaper!

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Roy....What would be ideas on the 3 tweeter if it fails in the future and one wanted to keep it?

And I know I have personally made some entertainment for you with my crazy ways sometimes.... :)

Hey Jeff,

It is always entertaining to hear from you! :)

There is no reason the HiVi Q1R tweeter, with the added coil, should not work as well, or better, for the AR-3 as the AR-3a. In fact, the HiVi's larger dome is more like the AR-3 tweeter than the smaller 3/4" dome tweeter found in the 3a. I have not tried it in the AR-3 but I have in the AR-2a and early AR-2ax, which used the same tweeter as the 3, with good results. Fortunately, the AR-3/2a/early 2ax tweeter has held up relatively well. ..and lots of them were made, resulting in decent availabilty and pricing at the moment.

Roy

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David's deceased midrange brings up another issue befalling AR-3 and AR-3/3a 12" woofers with alnico magnets.

His AR-3 mid's voice coil was pinched in the gap due to shifting of the pole piece. I have seen this only once before in an AR-3 mid, but have seen it a number of times in woofers. These magnets are bolted on and can be jarred out of alignment.

I believe this happens when the entire speaker is jarred during shipping. I have also seen front-wired AR-3a and AR-5 mid magnets broken off at the bottom of the cabinets. (The front-wired 3a and 5 mids have glue rather than bolts holding the magnets in place.)

Attached is a photo of David's mid with arrows showing the irregular voice coil gap which had pinched and damaged the voice coil. A center screw can be seen, which was used to adjust the gap when the mid was being manufactured.

Roy

post-101150-0-95864700-1424411912_thumb.

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  • 1 month later...

Does anybody have a success story and experience to share with me/us on how they were able to fix the plastic version of the grille frame? Each of mine were broken on one end before I got them. Not broken thru but just cracked enough to be bent and sagging. The saran plastic fabric is still attached and I am hoping to keep it that way since it looks pretty good since cleaning it.

My first thought is a combination of epoxy and a splint of some sort. I am afraid the torque on it applied by the saran fabric being taught, combined with how tight it fits will challenge it's integrity.

Current project status:

1. Cabs at finishing shop

2. Broken mid replaced (thanks roy)

3. Recapped (but thinking about replacing the 6uf with some oil filled versions)

4. Still pondering if I should just replace the rough feeling original pots with L Pads.

post-173623-0-32018200-1428673684_thumb.

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Does anybody have a success story and experience to share with me/us on how they were able to fix the plastic version of the grille frame? Each of mine were broken on one end before I got them. Not broken thru but just cracked enough to be bent and sagging. The saran plastic fabric is still attached and I am hoping to keep it that way since it looks pretty good since cleaning it.

My first thought is a combination of epoxy and a splint of some sort. I am afraid the torque on it applied by the saran fabric being taught, combined with how tight it fits will challenge it's integrity.

Current project status:

1. Cabs at finishing shop

2. Broken mid replaced (thanks roy)

3. Recapped (but thinking about replacing the 6uf with some oil filled versions)

4. Still pondering if I should just replace the rough feeling original pots with L Pads.

Not sure epoxy will stick to that frame. May be able use a section of an old fishing rod and some Goop for that.

I ordered a pair of pots from HK on the auction site just to see what they look like. Here is another option I stumbled on yesterday. Carl thought it was overkill. He hasn't responded to my email yet so I'm not sure if he is still producing these:

post-173498-0-12294200-1428676838_thumb.

http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=7517&p=94994

I don't see any reason for using NPE's for low-value caps. Am I missing something?

Update: Joe Breen still has his attenuator kits and or boards available. Price would be $21 for boards and $72 for kits to do a pair of speakers which is probably why you are not hearing much about it.

Roger

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DavidDru, on 10 Apr 2015 - 09:40 AM, said:

Does anybody have a success story and experience to share with me/us on how they were able to fix the plastic version of the grille frame? Each of mine were broken on one end before I got them. Not broken thru but just cracked enough to be bent and sagging. The saran plastic fabric is still attached and I am hoping to keep it that way since it looks pretty good since cleaning it.

My first thought is a combination of epoxy and a splint of some sort. I am afraid the torque on it applied by the saran fabric being taught, combined with how tight it fits will challenge it's integrity.

Current project status:

1. Cabs at finishing shop

2. Broken mid replaced (thanks roy)

3. Recapped (but thinking about replacing the 6uf with some oil filled versions)

4. Still pondering if I should just replace the rough feeling original pots with L Pads.

When I was removing my grills, I broke one grill in about the same place. I used Gorilla plastic glue on it, put the pieces together, and then clamped it with a piece of coat hanger to keep it straight until it dried. Came out strong and never knew it had been broken.

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When I was removing my grills, I broke one grill in about the same place. I used Gorilla plastic glue on it, put the pieces together, and then clamped it with a piece of coat hanger to keep it straight until it dried. Came out strong and never knew it had been broken.

Thanks LC, Was the fabric still attached?

And another question, when reattaching the grilles is everyone just adding some velcro?

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  • 2 weeks later...

So now that the cabs are back from the finishing shop and all drivers are are in hand, time to put all the pieces back together. Last thing I am debating is weather or not just to swap out the old original pots for the LPads I have for them. Give me some thoughts.

The originals are still very scratchy when you turn them but seem to measure in the full range. Now when I put them in will there be the possibility of spots that just don't work.

I think I am leaning towards using the LPads.

04241510.jpg

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I worked with my old pots and never did get them to my liking. I think at least a couple of the wipers were distorted. I finally ended up replacing all four with new L-pads and I am fine with that. The L-pads have been in about 2 1/2 years now without issue. I spent a lot of time on the originals in my 4x's as well and thought they were both perfect. After a couple of months one of them has a dead spot now.

der

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So now that the cabs are back from the finishing shop and all drivers are are in hand, time to put all the pieces back together. Last thing I am debating is weather or not just to swap out the old original pots for the LPads I have for them. Give me some thoughts.

The originals are still very scratchy when you turn them but seem to measure in the full range. Now when I put them in will there be the possibility of spots that just don't work.

I think I am leaning towards using the LPads.

I'm in the same sort of position. Do I rework the original Pots or do I replace them with L-pads.

Purists will hunt you down for replacing them ^_^ , but the reason why I bought AR's are for the sound and with reworked pots that could be an issue in the future.

So I will probably go for L-pads.

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  • 1 month later...

Well folks, success!

I have been able to finish up one of my 3's this weekend and am listening to her now. I will say she sounds really good, even with just one. I started slowly with a little Bill Evans jazz and then to see how vocals sound I went to Norah Jones. Testing those rebuilt and acquired mids of Roys. Wonderful! Played numerous other types of music including putting it through the ringer (albeit not turned up loudly yet) with a little Hiromi. Now the fantastic bass lines and drums of Phronesis, Love Song. Nice. Cant wait for both.

Here are a couple photos. Including the previously wired pots. I had restored them with the original pots up to the point that it became apparent that the mids needed work. Well, that waiting time allowed me to reassess those still rough original pots and I decided to go with LPads. I didn't want deteriorated pots, even though they measured in the full 0-16 range, being an issue sooner than later. So out came all my re-wiring from previous and in went the LPads.

The lPads are larger and the resistors are pretty wide as well so wire lengths had to change as well as orientation. Plus I used crimp connectors and the size of the male ends on the LPads are smaller (110) than those on the pots so all those had to be changed anyway. I only got the one speaker done because I don't have enough of the smaller connectors to finish until the proper stores are open after the holiday weekend. With the resistors being large they don't reach to the correct post on the LPad so I had to work around that with a pigtail on the yellow position 2 connections. Adding the gauge of the resistor to the other wires also made it challenging initially and some of the connections barely fit into the crimp connectors. Most of my wire is already 16 gauge. With all that now learned, the 2nd speaker should go quickly.

Off to a BBQ!

ar_pot10.jpg

lpad_c10.jpg

ar_com10.jpg

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