Patagorda Posted January 3, 2017 Report Share Posted January 3, 2017 Hi all, I've bought a pair of AR 10pi which I believed to be genuine, but now I'm having some severe doubts. - The logos are copper/brass, like on the first series. - There is no AR sticker on the speaker front or back - On the inside of the lid there is a little shield that says AR 10pi and a serial number, plus, in the center, a small circular metal logo that reads "Varec Milano". - I've read posts about Italian replicas but they're from different firms, not Varec. Any tips on how to determine whether these are genuine or not are greatly welcomed. Jasper Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 3, 2017 Report Share Posted January 3, 2017 Hello Jasper, Please, post some good pictures of your 10 Pi. Luigi Quote Link to comment Share on other sites More sharing options...
Patagorda Posted January 3, 2017 Author Report Share Posted January 3, 2017 Hi Luigi, For some reason I'm unable to upload photos. I've tried all methods available. I could mail them to you if you can share your email address. Cheers, Jasper Quote Link to comment Share on other sites More sharing options...
Patagorda Posted January 3, 2017 Author Report Share Posted January 3, 2017 Hope this works: https://drive.google.com/open?id=0BwjNgbnEmlG2cnhNMmxaNVZqMFlGS2M2S3dZeGlvdjdtb3Bz https://drive.google.com/open?id=0BwjNgbnEmlG2eUg3QnY4a1E0OE03SmFpQzZmOXNsYWFiRzgw https://drive.google.com/open?id=0BwjNgbnEmlG2V081ZzFRemZlR0l0QW52bjhjN1lPRmFiTVNV https://drive.google.com/open?id=0BwjNgbnEmlG2aV9IdE5zektrdzNOZlk2cTliYWZjZENjN19z Quote Link to comment Share on other sites More sharing options...
ra.ra Posted January 3, 2017 Report Share Posted January 3, 2017 Yes, your images are viewable, and it appears that all drivers are original. I am no expert on the 10-pi, but according to the various drivers pictured in the AR-3a restoration manual, all of your drivers are from an early version (Mk. I ???): woofer (A.4); midrange (A.13) and tweeter (A.21). I may be mistaken, but I always thought that little (Varec) button was simply a magnet to keep the wooden door closed, and if you view this attached thread, you'll see a pair of 10-pi's with the ID sticker inside the door flap like yours. You've got yourself some very nice speakers there. http://www.classicspeakerpages.net/IP.Board/index.php?/topic/1520-ar10pi-crossover-schematics/ Quote Link to comment Share on other sites More sharing options...
Patagorda Posted January 3, 2017 Author Report Share Posted January 3, 2017 Phew! This means a lot. The sound is awesome, but to know I've got the genuine article is fabulous. Thanks! Quote Link to comment Share on other sites More sharing options...
ra.ra Posted January 3, 2017 Report Share Posted January 3, 2017 If you read up some more and look at additional images, you'll find a few variations of this speaker model, but there is nothing obvious to suggest that any part of yours are not original. Quote Link to comment Share on other sites More sharing options...
genek Posted January 3, 2017 Report Share Posted January 3, 2017 http://www.varec.it/home-ENG.aspLNG=ENG&art=CHI.html Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 3, 2017 Report Share Posted January 3, 2017 The single loudspeaker picture you linked is definitely an original AR 10 Pi MKI (year 1975-76). Check accurately both loudspeakers are completely identical (drivers and furnitures). Also the magnetic lock "VAREC MILANO" is original. In the attached link you can see some pictures of the AR 10 Pi (Pi Greco in Italian) Replica: Luigi Quote Link to comment Share on other sites More sharing options...
tysontom Posted January 3, 2017 Report Share Posted January 3, 2017 4 hours ago, Patagorda said: Hope this works: https://drive.google.com/open?id=0BwjNgbnEmlG2cnhNMmxaNVZqMFlGS2M2S3dZeGlvdjdtb3Bz https://drive.google.com/open?id=0BwjNgbnEmlG2eUg3QnY4a1E0OE03SmFpQzZmOXNsYWFiRzgw https://drive.google.com/open?id=0BwjNgbnEmlG2V081ZzFRemZlR0l0QW52bjhjN1lPRmFiTVNV https://drive.google.com/open?id=0BwjNgbnEmlG2aV9IdE5zektrdzNOZlk2cTliYWZjZENjN19z As others have indicated, these are definitely AR-10π speakers—the original version—sometimes unofficially called the "Mark I" version. The original version is characterized by the use of the brass logo plate, the yellow-orange ¾-inch soft-dome tweeter, the earlier AR-3a-style woofer and the solid-veneer back panel (which easily delaminated in use and was later changed). Serial Numbers in the 4600 range. I think this particular pair are European (Holland) versions and judging by the serial number, this pair was likely built in October or November, 1976. In the US, AR began using Ferrofluid tweeters on September 22, 1976, beginning with serial number 6278, and this pair has a later serial number; however, most of the Ferrofluid tweeters were black rather than orange, so this might have had the earlier tweeters, perhaps shipped to Europe. The second version of the AR-10 with the "new look" came in June, 1977. —Tom Tyson Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 3, 2017 Report Share Posted January 3, 2017 @tysontom Thank you Tom for all the precise information you provide us. I've always thought that probably the "H" and "E" printed before the loudspeaker serial number meant Holland and England respectively but I'm not sure. Do you know anything about it? Do you know if there was any relationship between American and European serial numbers or they were completely independent? Luigi Quote Link to comment Share on other sites More sharing options...
tysontom Posted January 4, 2017 Report Share Posted January 4, 2017 22 hours ago, fedeleluigi said: @tysontom Thank you Tom for all the precise information you provide us. I've always thought that probably the "H" and "E" printed before the loudspeaker serial number meant Holland and England respectively but I'm not sure. Do you know anything about it? Do you know if there was any relationship between American and European serial numbers or they were completely independent? Luigi Hi Luigi, I'm unsure of the details of the England and Holland production protocol; I do know that the drivers were originally produced in Cambridge, Massachusetts (and later in Norwood) and shipped to Europe. Later, some drivers were produced in Europe along with cabinets. I need to research this a bit to find out what happened. However, I honestly don't know how Teledyne AR worked the serial-number range. For example, I always understood that the orange tweeters were non-Ferrofluid drivers and that the black tweeters were Ferrofluid, yet the serial number of Jasper's (Patagora's) AR-10s fall into the Ferrofluid-tweeter range, another mysterious thing in the world of high-fidelity loudspeakers! I do agree with you that the "E" and "H" preceding the number indicated England or Holland production. Veering off topic a bit, Acoustic Research at first used an export service, Delrama, Inc., to ship products across the globe, but later expanded production and testing into Europe. Delrama became unnecessary, and I acquired quite a lot of NOS products that came from Delrama inventory, including the last existing AR-3a "cutaway" speaker. It was number 2 of 2 made, I believe; the first two were dismantled after the AR Music Room was discontinued in 1973. The AR-3a "cutaway" was a hand-made work of art made by Sumner Bennett with the help of AR's cabinet-maker. After this one, the "cutaway" AR-3a is extinct, but it will be protected. The AR-3a "cutaway" is similar to the AR-11 "Visible Speaker," another rare item. The AR-3a "cutaway" was used in Italy, Germany, England, France and Holland as well as in shows in Australia and China from time to time. It traveled the earth.for several years, starting in 1968, accompanying executives from Acoustic Research, such as Roy Allison, Sumner Bennett, Martin Borish and Gerald Landau. After AR went to internal, self distribution, Delrama was out and didn't know what to do with the AR-3a "visable," so I acquired it from them along with their existing inventory of NOS AR-3, AR-3, AR-3a and AR-1 service-replacement parts. I've given most of those parts to AR friends in need. The AR-11 "Visable" was an attempt by Teledyne AR to do the same thing with their Advanced Development Division speakers, and several (probably a dozen or more) of the "Visable" speakers were made available for franchised Teledyne Acoustic Research dealers in the US (and perhaps Europe, too). It could be purchased with a small sine-wave generator and amplifier and an AR metal speaker stand, but only a few dealers opted for this interesting sales aid. I apologize for straying off topic (original topic was the AR-10). --Tom Tyson Quote Link to comment Share on other sites More sharing options...
JKent Posted January 4, 2017 Report Share Posted January 4, 2017 1 hour ago, tysontom said: I acquired quite a lot of NOS products that came from Delrama inventory, including the last existing AR-3a "cutaway" speaker. So this IS you! Quote Link to comment Share on other sites More sharing options...
tysontom Posted January 5, 2017 Report Share Posted January 5, 2017 19 hours ago, JKent said: So this IS you! Yes, yes. There I am explaining the intricacies of the Electro-Voice Interface A. That is Steve F "glazing over." Quote Link to comment Share on other sites More sharing options...
Steve F Posted January 5, 2017 Report Share Posted January 5, 2017 Now Tom, I would never glaze over at one of your fascinating explanations! Steve F Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 6, 2017 Report Share Posted January 6, 2017 On 04 gennaio 2017 at 10:10 PM, tysontom said: Hi Luigi, I'm unsure of the details of the England and Holland production protocol; I do know that the drivers were originally produced in Cambridge, Massachusetts (and later in Norwood) and shipped to Europe. Later, some drivers were produced in Europe along with cabinets. I need to research this a bit to find out what happened. However, I honestly don't know how Teledyne AR worked the serial-number range. For example, I always understood that the orange tweeters were non-Ferrofluid drivers and that the black tweeters were Ferrofluid, yet the serial number of Jasper's (Patagora's) AR-10s fall into the Ferrofluid-tweeter range, another mysterious thing in the world of high-fidelity loudspeakers! --Tom Tyson Thank you Tom for answering and also for your "off topics" as they always are very accurate, instructive and informative for all of us. As you have said and as far as I know the yellow-orange 3/4-inch soft-dome tweeters never had ferrofluid. As far as I've seen the yellow-orange tweeters were manufactured until, at least, the first months of 1976. If I remember correctly, before the biginning of production of the black 3/4-inch soft-dome tweeter with ferrofluid, I think there was a brief production of black 3/4-inch soft-dome tweeters without ferrofluid very similar in construnction as the yellow-orange ones ( with the terminals crossing tweeter plasic flange still having a shape of "I" and not "L"). In other words they look like a 4 Ohm version (without ferrofluid? ) of the early 8 Ohm AR 12 tweeters. I never disassembled them ( they were functioning) and unfortunately I didn't note and do not remember their date of manufacturing. These black domes tweeters are rather rare. So I think that if Jasper's (patagorda's) 10s were assembled at the end of 1976, they could now have an "older" no-ferrofluid yellow-orange tweeter for some unknown reason (maybe the yellow-orange tweeter were used later as "replacement parts" for blown black ferrofluid tweeters that originally were used in the factory assembly). Jasper (patagorda) could check the date of manufacturing printed on the back of his 10s tweeters (and the other drivers) so we could learn more about the history of AR speakers. Unfortunately, today it is very hard to know exactly all that happened at AR during the seventies. It seems to me that (maybe I'm wrong and if so, I apologize) unfortunately none of the numerous engeneers or workmen that worked at AR in USA or Europe in the '70s writes or has written in these pages providing all of us with useful and instructive information about AR. It seems that they are not so enthusiastic about AR speakers as we are. So, unfortunately, a lot of precise historical information about those years will be lost forever. Luigi Quote Link to comment Share on other sites More sharing options...
Patagorda Posted January 6, 2017 Author Report Share Posted January 6, 2017 Hi Luigi, I'd be happy to - as long as I don't have to take anything apart. Not too comfortable with messing with these beauties. Where can I find these dates? best, j Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 7, 2017 Report Share Posted January 7, 2017 On 06/01/2017 at 7:30 PM, Patagorda said: Hi Luigi, I'd be happy to - as long as I don't have to take anything apart. Not too comfortable with messing with these beauties. Where can I find these dates? best, j Hi Jasper, Unfortunately you should dismantle your AR 10s in any case. In my opinion, in a vintage loudspeaker it is obligatory to check carefully that everything is OK especially the crossover capacitors. After more than 40 years the original bipolar electrolytic capacitors could very probably be out of specs (abundantly) . For example I have often found the 10 uF industrial cap (used in the tweeters crossover network of AR 10 Pi and 11) more than 300% out of specs (I found some that measured more than 35 uF!) . This is very dangerous to tweeters and they can easily burn out. If you are not used to disassemble and check a loudspeaker you'd better not to do it as you could damage it. You could ask some of your friends that are skilled in this kind of works to help you. Anyway I recommend that you check your 10 Pi crossovers. There are lot of threads about recapping a crossover with bipolar electrolytic or film capacitors. I don't want to discuss about the sound of capacitors but I only recommand that you use not out of specs fresh bipolar electrolytic or film capacitors (always measure their capacitance before using. Voltage: 63V or more). Check also the crossover bobbins as I sometimes found some mistakes made during factory assembly (at least in Europe). As regards driver date of manufacturing it is usually printed on each driver back (in more recent drivers it is printed on their paper labels). With reference to tweeters, you should unscrew the 3 screws of each one. Then you can carefully remove the tweeter. It's not always necessary to disconnect the wires (although it would be very useful to clean the tweeter and wire terminals: The high notes will improve) to see the back of these tweeters. On the back of the driver you can read the tweeter part number (200011-1 but on early versions it was omissed), the number 561 and others digits that indicate the year ( in your case 75 or 76) and the week of manufacturing. For instance 7544 means the 44th week of 1975. It is very simple to remove a tweeter from the cabinet but you should pay attention to the following aspects: 1) the fabric dome is delicate and you should not damage it with the screwdriver tip and/or the screws because of the tweeter magnetsism that is very high (maximum) just in correspondence to the yellow fabric dome. 2) so you should carefully touch only the screw head by the screwdriver bit paying attention not to move close to the fabric dome. 3) after unscrewing one single screw, carefully move it away from the tweeter dome holding it firmly and when you have to screw it again be careful to hold it between you fingers firmly until it begins to screw in. If it slips out of your fingers it could be attracted towards the fabric dome damaging it. Should you decide to check your AR 10s (and as I said I recommend that you check them: your AR 10s and your ears will thank you) please let us know more about the history of these AR speakers informing us about the date of manufacturing of tweeters (and if possible of the other drivers). Luigi Quote Link to comment Share on other sites More sharing options...
JKent Posted January 7, 2017 Report Share Posted January 7, 2017 Jasper, Be sure to look at the excellent restoration guide for the AR-3a: Your 10pi speakers are more modern versions of the 3a and much of the information in the restoration guide is relevant. Removing the woofer and the fiberglass stuffing to gain access to the crossover capacitors may seem daunting but if you have some experience using tools, maybe soldering, and have a place to work on them it's not really difficult. And there are lots of guys here to help. OTOH... Those are beautiful speakers and I'm inclined to say "if it ain't broke don't fix it." -Kent Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 7, 2017 Report Share Posted January 7, 2017 On 07/01/2017 at 5:12 PM, JKent said: Jasper, Be sure to look at the excellent restoration guide for the AR-3a: Your 10pi speakers are more modern versions of the 3a and much of the information in the restoration guide is relevant. Removing the woofer and the fiberglass stuffing to gain access to the crossover capacitors may seem daunting but if you have some experience using tools, maybe soldering, and have a place to work on them it's not really difficult. And there are lots of guys here to help. -Kent Excellent advise Kent! I did forget to recommend that Jasper read the excellent work "restoring the AR-3a" . Although it only refers to 3a, he could find useful and general information about dismantling and checking a loudspeaker. Luigi Quote Link to comment Share on other sites More sharing options...
Patagorda Posted January 7, 2017 Author Report Share Posted January 7, 2017 Hi Luigi & Kent, I'm not 100% sure but I don't believe the caps have been renewed. The speakers came with receipts of repairs and apart from reforming and rekoning I don't believe they've had any work done. I'm not adept at soldering or anything beyond IKEA DIY, so I'm reluctant to dig into them myself. There is someone in the neighbourhood who is an experienced speaker restorer who already did a fab job on reforming my previous AR92s (which I traded in for these) whom I could ask. Still, the key question is: should I leave them as is - they sound just great - or do this essential maintenance before something breaks down and I kill my tweeters. Any tips much appreciated! Cheers, jasper best, j Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 7, 2017 Report Share Posted January 7, 2017 24 minutes ago, Patagorda said: or do this essential maintenance before something breaks down and I kill my tweeters? As I said, in my experience a crossover check (carried out carefully) is always strongly recommended in a vintage speaker especially for driver safety. Luigi Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 7, 2017 Report Share Posted January 7, 2017 On 04 gennaio 2017 at 10:10 PM, tysontom said: The AR-11 "Visable" was an attempt by Teledyne AR to do the same thing with their Advanced Development Division speakers, and several (probably a dozen or more) of the "Visable" speakers were made available for franchised Teledyne Acoustic Research dealers in the US (and perhaps Europe, too). It could be purchased with a small sine-wave generator and amplifier and an AR metal speaker stand, but only a few dealers opted for this interesting sales aid. I apologize for straying off topic (original topic was the AR-10). --Tom Tyson Hi Tom, Observing the AR 11 "Visable" I have noticed that it is a so called "MKII" version. So it seems a little strange to me that the stuffing is fiberglass instead of polyester as usually used in the "MKII" version. Also the woofer voice coil former seems not to be aluminum whereas I have usually found aluminum former during the AR 11 MKII woofer restoring. Did the early AR 11 MKII use a fiberglass stuffing and a not aluminum voice coil former for the 12" woofer? Luigi Quote Link to comment Share on other sites More sharing options...
tysontom Posted January 8, 2017 Report Share Posted January 8, 2017 10 hours ago, fedeleluigi said: Hi Tom, Observing the AR 11 "Visable" I have noticed that it is a so called "MKII" version. So it seems a little strange to me that the stuffing is fiberglass instead of polyester as usually used in the "MKII" version. Also the woofer voice coil former seems not to be aluminum whereas I have usually found aluminum former during the AR 11 MKII woofer restoring. Did the early AR 11 MKII use a fiberglass stuffing and a not aluminum voice coil former for the 12" woofer? Luigi Hi Luigi, You're right that it is the "New-Look" Mark II version, but I think the AR "Advanced Development Division" marketing people probably used whatever they had to make the cutaway versions. The "ADD" moniker went away pretty soon after the "New Look," too. These cutaway versions were also very early in the Mark II process, but there are no serial numbers on either of the display speakers. AR also made a beautiful, single AR-3 cutaway, but it was apparently dismantled at some point. This speaker was on display in the AR Music Room in New York's Grand Central Terminal. It was powered by a 5 Hz sine wave, with the woofer slowly pumping back and forth to show the acoustic-suspension principle. There was a Plexiglas AR Turntable, but it too was destroyed. Fiberglass was used well into the later versions, but I don't know the date of change to polyester. Another thing: fiberglass can be placed in "squares," to appear to be neatly packed inside the cabinet, whereas polyester would be all over the place. The woofer voice-coil former is Nomex, commonly used in this woofer, but late in the 70s AR began using aluminum for the former. Aluminum dissipates heat better, yet Nomex can stand higher temperatures. --Tom Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted January 8, 2017 Report Share Posted January 8, 2017 On 1/8/2017 at 5:35 AM, tysontom said: Hi Luigi, You're right that it is the "New-Look" Mark II version, but I think the AR "Advanced Development Division" marketing people probably used whatever they had to make the cutaway versions. The "ADD" moniker went away pretty soon after the "New Look," too. These cutaway versions were also very early in the Mark II process, but there are no serial numbers on either of the display speakers. AR also made a beautiful, single AR-3 cutaway, but it was apparently dismantled at some point. This speaker was on display in the AR Music Room in New York's Grand Central Terminal. It was powered by a 5 Hz sine wave, with the woofer slowly pumping back and forth to show the acoustic-suspension principle. There was a Plexiglas AR Turntable, but it too was destroyed. Fiberglass was used well into the later versions, but I don't know the date of change to polyester. Another thing: fiberglass can be placed in "squares," to appear to be neatly packed inside the cabinet, whereas polyester would be all over the place. The woofer voice-coil former is Nomex, commonly used in this woofer, but late in the 70s AR began using aluminum for the former. Aluminum dissipates heat better, yet Nomex can stand higher temperatures. --Tom Thank you Tom, as far as I've seen in Italy and Europe where the ADD series speakers were rather common, the polyester stuffing and the the woofer aluminum voice coil former were used very early in the "MKII" series (probably with its introduction). Anyway, although I've seen many of these speakers I haven't obviously seen all of them and now I regret I didn't note at least the serial numbers and the main characteristics of all the speakers I have analyzed. Luigi Quote Link to comment Share on other sites More sharing options...
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