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Euro AR-6's arrived

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The two pair of Euro AR-6's arrived from flea bay today. They were almost packed well. One trim piece on the cabs with the raised grill lip broke off on one side and will need to be glued. I'm sure these will keep me busy for quite some time. The organic pilsner is to show scale and keep me happy :D

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Quick analysis revealed serials in the 27,000 and 37,000 range. The labels on these come off easily unlike the US versions. Three front wired tweeters and one rear wired. The rear wired tweeter has a break in the lead at the cone junction. I can probably fix that one since I did one the other day on a 4xa -- that is another story. Another has a dimpled cone -- been there recently so it should be easy to fix. One of the wax caps on the 27K pair was floating around inside the cabinet -- staple fail.

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One bad alnico woofer that it looks like someone put into overdrive without a surround. I'll have to cut the dust cap off and see if the coil lead is repairable. The voice coil looks okay from the side. The grills on the 27K cabs were hot-glued and had never been removed.

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One crossover board was entirely detached on the 37K speakers. No staples here only some type of hot glue. I just went ahead and pulled the other one as well. Not my favorite particle board for baffle and back as it is the coarse grain-type which is weaker in my opinion. I will probably coat the insides with epoxy to stabilize it.

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The 37K serial has ceramic woofers with the 2nd order resistor/cap combo. The cones on these are much stiffer than the rippled cones on the 27K pair.

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Here is the crossover with 3 position switch.

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The pots on the 27K crossover are not great but not all that bad either.

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The fiberglass l got a bit warm here. Whoever owned these obviously needed some JBLs.

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The ceramic woofers have gaskets under the surround attached to the baskets.

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Some AR marked caps.

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I've seen some people referring to this as a Zobel network but it is not the right set up for that. I think Zilch covered this circuit when he did his AR-4 mods.

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All and all it looks like a typical transaction on the auction site. I figured I'd get at least one pair and some spare parts out of this :)

Roger

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thanx for the update Roger. I have always been on the fence about that brown/gold grille cloth, up close I really like the detail, but somehow from a distance not so much. Will look for progress as you bring these back to life.

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thanx for the update Roger. I have always been on the fence about that brown/gold grille cloth, up close I really like the detail, but somehow from a distance not so much. Will look for progress as you bring these back to life.

My original AR-5's had the dark brown grill cloth. One advantage is they don't show the age discoloration the light cloths do. I imagine they are not as acoustically transparent as the light cloth though. Will probably be making haste slowly on these because of other time demands.

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Another has a dippled cone -- been there recently so it should be easy to fix.

Do you mean a pushed in cone?

My tweeter has the "dust cap" pushed in and I'm wondering how to fix that.

I've read it somewhere but cannot find it.

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Do you mean a pushed in cone?

My tweeter has the "dust cap" pushed in and I'm wondering how to fix that.

I've read it somewhere but cannot find it.

Here is Kent's technique: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8335&p=101775

Here is the before photo showing the dimpled cone:

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And here is the result using the tube shown before adding a light coat of watered-down pva glue to stabilize the dome. It is not perfect but it sounds fine. There are more details in the thread above.

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And here is the vacuum cleaner method. I may try this one using a battery vac which is easy to control suction while using: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=4956

Roger

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Was able to revive the dead woofer and tweeter today by bridging the breaks in the lead in wires. after removing the dust cap I found the woofer lead was open on the front of the cone and the tweeter was open near the post. They ohm out correctly anyway. I'd give about a 95% confidence rating on the tweeter fix and 98% on the woofer. Lot's of fun. Try soldering a wire the thickness of a hair with a lacquer coating :)

One of the cabinets with the raised grill lip was lacquer finished. It also had a sand colored back panel while the others were dark brown. I kind of like the lacquer finish as a wipe down with lacquer thinner pretty much removed all the blemishes. I'll see if I can track down some lacquer sticks in the correct shade to fill the rest of the blemishes and put a fresh coat of lacquer on that pair.

Life goes on :rolleyes:

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It's great to see that both pairs are largely intact, all-original, and in relatively good shape. The 27K pair with the ribbed cones have those great early woofers with the floppy cone and the massive alnico magnet, but from what I see, your pics do not show any obvious damage. Despite the small dent, the tweeters look good, too.

The 37K pair with the Euro-style cabinets also looks very good. If you look closer at the woofers, you'll see that the spider attachment also has the thin spacer ring similar to the surround-basket perimeter. I think this adjustment prevented the voice coil from bottoming out. Also, I believe you may be correct that the attached resistor and capacitor does not constitute a true Zobel circuit, but unless and until someone describes it more accurately, I think it's a fine term to describe this particular configuration. I suspect each woofer has a 24uf cap and a 10 ohm resistor?

Your speakers appear to have two types of caps - Industrial Condenser wax blocks and silver Sprague Royalitics. I am no expert, and it is definitely worth measuring just to know their current values, but I do not believe that the Royalitics have a similar track record for sustaining their original values the way that the Sprague Compulytic capacitors do. In other words, even though I tend to not be an automatic cap replacer with vintage speakers, both pairs here might well benefit from all new capacitors. Perhaps some others here have more extensive experience on this matter with actual aged measurements.

Perhaps this is a 'typical' auction site transaction, but when one is purchasing two pairs of 40 year-old AR's sight-unseen with no documentation of any of the eight drivers, I'd venture to say that you made out very well and have two very restorable pairs of terrific, vintage, real bookshelf speakers on your hands. Great purchase, keep us posted.

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It's great to see that both pairs are largely intact, all-original, and in relatively good shape. The 27K pair with the ribbed cones have those great early woofers with the floppy cone and the massive alnico magnet, but from what I see, your pics do not show any obvious damage. Despite the small dent, the tweeters look good, too.

The 37K pair with the Euro-style cabinets also looks very good. If you look closer at the woofers, you'll see that the spider attachment also has the thin spacer ring similar to the surround-basket perimeter. I think this adjustment prevented the voice coil from bottoming out. Also, I believe you may be correct that the attached resistor and capacitor does not constitute a true Zobel circuit, but unless and until someone describes it more accurately, I think it's a fine term to describe this particular configuration. I suspect each woofer has a 24uf cap and a 10 ohm resistor?

Your speakers appear to have two types of caps - Industrial Condenser wax blocks and silver Sprague Royalitics. I am no expert, and it is definitely worth measuring just to know their current values, but I do not believe that the Royalitics have a similar track record for sustaining their original values the way that the Sprague Compulytic capacitors do. In other words, even though I tend to not be an automatic cap replacer with vintage speakers, both pairs here might well benefit from all new capacitors. Perhaps some others here have more extensive experience on this matter with actual aged measurements.

Perhaps this is a 'typical' auction site transaction, but when one is purchasing two pairs of 40 year-old AR's sight-unseen with no documentation of any of the eight drivers, I'd venture to say that you made out very well and have two very restorable pairs of terrific, vintage, real bookshelf speakers on your hands. Great purchase, keep us posted.

I'll see if I can find the reference on the parallel RC woofer circuit.

I wasn't aware Sprague made the Royalitics. I don't have any way to measure the esr but I can check the capacitance values. The wax caps usually drift high.

I like the 6's and I imagine three pairs will produce quite a sound field :)

Besides that, I've never met a classic AR I didn't like. These are most probably GI bring backs although the two different finishes on the raised lip pair beg some questions -- one oil, one lacquer.

Making haste, slowly ...

Roger

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Take your time with the restorations, but you've definitely got the makings of two nice pairs there.

Roger, I think I may have mislead you about the Royalitic caps - - it's quite possible that, just like the wax blocks, the original manufacturer was Industrial Cond. Corp.

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Back on the Euro AR-6's today, well, one anyway.

Put an HK 25W 14 ohm (supposed to be 15) pot in to replace the AP pot that had seen better days. Used a Madisound surplus 10mfd to replace the ICC wax cap which had drifted up around 14mfd. Crimped everything together and made it so I can change it out easily if necessary. I don't think I will use these pots again -- L-pads look easier. Needed a cover so I used a pvc pipe cap that was laying around.

Fired her up with the pot set in mid position and she sounds great :) Will need to trim the stem on the pot and add a knob.

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Will have other distractions tomorrow so it may be awhile before I do the other one.

Roger

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Excellent.

40 years from now when someone goes to restore these again they will open it up, find that Lasco PVC cap and spend a bunch of time trying to figure out what this Lasco company is and why cant I find any info on them related to speakers or electronics! Cool. Keeping em on their toes.

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Ha, ha, ha, didn't think of that or I would have added a bogus AR part number :lol:

Finished the other one today complete with Lasco cap. This one had a break in the woofer leads on top of the cone repaired. Both speakers had been driven hard enough to scorch the fiberglass next to the pots.

They are sounding great once again. I'm really amazed how much bass these put out.

Roger

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Having some fun with the last pair of Euro AR-6's: ceramic magnets, "so-called" Zobel circuit and switched tweeter balance controls. I changed out the ICC Royalytic caps in one with Madisound surplus and Carli's and left the other one stock after refoaming the woofers with JBL surrounds and reattaching the crossovers. The fiberglass stuffing on this set was 15 and 10 ounces so I balanced them out in 12-13 ounce range.

The speaker with the new caps sounds brighter and bass thin while the stock speaker sounds rather dull. I am going to keep playing around with the caps since there is a distinct difference that is clearly audible. Hopefully it is not just the drivers. Need to wire up the other two sets of 6's and do so serious A/B time.

Roger

Added: Need to do a little more experimenting with stuffing volume. Carl gets into its effect on cabinet Q and bass extension here: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8427&hl=

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Interesting update, Roger. Most of that report sounds pretty good, except the comment about the weak bass output is a bit baffling - - my understanding is that the AR-6, even the later version with the ceramic woofer, was very well respected for its extraordinary low frequency performance from such a small driver and cabinet. Meanwhile, the improved, brighter sound of the re-capped speaker is good to hear but not surprising at all - - I suspect those original Royalitic caps are rather tired by now. Am looking forward to your further evaluations.

My experience with the JBL surrounds was that they are rather easy to install - - not quite foolproof, but no struggle at all. For the 24uF "zobel" cap, did you assemble a group of two or three caps to create this value, and if so, did you glue this bunch to the woofer magnet?

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Interesting update, Roger. Most of that report sounds pretty good, except the comment about the weak bass output is a bit baffling - - my understanding is that the AR-6, even the later version with the ceramic woofer, was very well respected for its extraordinary low frequency performance from such a small driver and cabinet. Meanwhile, the improved, brighter sound of the re-capped speaker is good to hear but not surprising at all - - I suspect those original Royalitic caps are rather tired by now. Am looking forward to your further evaluations.

My experience with the JBL surrounds was that they are rather easy to install - - not quite foolproof, but no struggle at all. For the 24uF "zobel" cap, did you assemble a group of two or three caps to create this value, and if so, did you glue this bunch to the woofer magnet?

Yes, some of it is puzzling but I will spend some time on this since I find it interesting and these speakers are easy to work on. It was fairly late when I finished yesterday and I only played one recording, so lot's of variables to weigh. The three sets of 6's all have some differences in construction so it will be interesting to A/B/C listen test them once the last crossover is finalized. The 7's will be arriving shortly. It's a AR kind of year :)

The three bundled caps were secured with a wire tie that acts as a stand-off from the magnet. The original cap was hanging in free-space so I didn't see any need to further secure them. Also I used the original foam basket gasket because I was planing on going back in. I'll eventually replace that to improve the seal.

I'm wondering if adding the spacer gaskets to the woofer spider and cone cut some of the low-end response. These are my first ceramic magnet woofers so no experience here. It is definitely impossible to bottom out these voice coils which would have saved AR money on warranty repairs.

There are differences in the tweeters. I'll have to check for numbers I'm thinking some of these are the same tweets used on the 8's.

If I had to bug-out with just a pair of AR-6's and a 60 watt amp I wouldn't feel deprived ;)

Roger

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I found a pair of AR-6 speakers. Are they worth the asking price of 175 Midwest dollars if the are in good condition?

Greetings and welcome to the AR Diaspora club .... I'd say if you like them, yes. I paid more for my first pair but they had unmolested "unfinished pine" cabs. Back in "AR Land" you can probably find them for quite a bit less if you have the patience.

Roger

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Thank you, Roger – I will have to give them another look. The good thing is they are 5min away from where I live so no shipping.

In the meantime, I am starting to get overwhelmed so it is time to put your good sense to practice “Making haste, slowly “

Huge ACW buff by the way. Our group, sadly, made what could be our last hurrah at Vicksburg last summer – ending our 6 year run at the Trans-Mississippi/Western Theater.

Festina lente…

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They should sound great with your 2ax's through your 555 amp. I'm listening to them with a set of 5's at the moment and it is impressive. I plan on powering three sets of each at the same time before the year is over. Just need a little more time to work out the logistics. Not quite in the middle of the orchestra with two sets.

A thought comes to mind about those old electrolytic crossover capacitors that have been sitting idle for years, perhaps, it may take them awhile to reform.

ACW, never thought much about it since my childhood days of collecting bubble gum cards. Last time I was visiting my ancestral homeland I spent some time in the cemetery at Salisbury, NC. It was hard not to be overcome by the emotion though. It made a strong impression.

Roger

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Thanks for the kick on the AR-6. I really could not believe how close they sounded to the AR-2ax speakers. They are in ugly shape cosmetically (Marker and engraved name and phone# on the side and top) but they more than make up for it in sound they produced on that day. I figure if I make it through the AR-2ax repair this one should not be as painful...

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AR-6 Front

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AR-6 Back

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Thanks for the kick on the AR-6. I really could not believe how close they sounded to the AR-2ax speakers. They are in ugly shape cosmetically (Marker and engraved name and phone# on the side and top) but they more than make up for it in sound they produced on that day. I figure if I make it through the AR-2ax repair this one should not be as painful...

Knew you would like them :)

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Having some fun with the last pair of Euro AR-6's: ceramic magnets, "so-called" Zobel circuit and switched tweeter balance controls. I changed out the ICC Royalytic caps in one with Madisound surplus and Carli's and left the other one stock after refoaming the woofers with JBL surrounds and reattaching the crossovers. The fiberglass stuffing on this set was 15 and 10 ounces so I balanced them out in 12-13 ounce range.

The speaker with the new caps sounds brighter and bass thin while the stock speaker sounds rather dull. I am going to keep playing around with the caps since there is a distinct difference that is clearly audible. Hopefully it is not just the drivers. Need to wire up the other two sets of 6's and do so serious A/B time.

Roger

Added: Need to do a little more experimenting with stuffing volume. Carl gets into its effect on cabinet Q and bass extension here: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8427&hl=

Well, the AR-6 triumvirate is up and running. I replaced the caps in the crossover of the final speaker of a set that originally had Royalytics and the sound evened up on that set. I think I had originally made a comment somewhere that cap esr was of no merit on these old npe's and no one called me on it. That was certainly not the case here where the cap esr is in series with the tweeter voice coil thereby lowering the output of the tweeter.

The three sets playing together makes for a decent show. You can change the sound stage by changing the angle to reflecting surfaces and listening position of each speaker in the stack. Will have to spend some more time with them.

Meanwhile, back to the AR-5 triumvirate :) Seems like I need to consider replacing the Sprauge caps at this point.

Roger

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You sure these are Euro models? They have Cambridge addresses on their labels and no fluting on the face frames.

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You sure these are Euro models? They have Cambridge addresses on their labels and no fluting on the face frames.

Yes, Dutch versions with HG serial prefixes. One set has fluting the other doesn't. Then I have a Cambridge Unfinished Pine set to round out the bunch.

Here is the original photo in post #1: http://www.classicspeakerpages.net/IP.Board/uploads/monthly_03_2015/post-173498-0-74351000-1427598609.jpg

The fluting was broken and dented on the set that had it and I was it expecting it to be a solid piece of walnut. Surprise, it looks like birch veneered with walnut. The finish doesn't match on this set at all and I expect I will end up putting a Minwax polyshade color coat on them at some point.

Roger

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