Giorgio AR Posted December 11, 2021 Report Share Posted December 11, 2021 I insert a report on the stacking of a pair of AR2 with another AR2a on the correct section; have been in this configuration for some time, but previously they were connected to a very good, old and good sounding Philips RH521 amplifier, 30 x 2 w at 4 ohm The two pairs were used alternately and to the AR2 I had paired on the top a pair of small AR1MS used as medium / high section, using only the woofer of the AR2, with the iterposition of a filter cut at 2000hz or slightly below, I don't remember exactly. I retired the old Philips that was starting to have a noticeable hum and replaced with a more recent Marantz PM78, also equipped with a remote control (an incredible convenience being placed at about 2.15 meters high!), This amp is particular because it works in " class A "(25W x 2 at 8 ohm, a little more at 4 ohm) or in" class AB "(100w x 2 at 8 ohm, but 190w x 2 at 4 ohm!). At this point I decided to remove the small AR1MS, reconnected the double mid / tw of the AR2 and so I listened to the two pairs together (switches A and B speakers of the amplifier both on and as always defeat tones ... there is a special button on the amplifier) ... I entered another world. In both modes: "class A" or "AB" a big change, the impression of the low range was not equal to the sum of the two woofers, but much higher, the remaining mid-high range perfectly integrated and slightly behind, never tiring; same sensation from volumes of tenths of a watt, up to high wattages. I was very satisfied with it, since then the system works with both pairs always connected (every now and then I only listen to the AR2a, among my favorite ARs alternating with listening to the AR2s, they sound the same, clearly the AR2a have the supertweeter that makes them feel more complete) But the magic comes when both pairs play together, why? ... I asked myself the question many times these days ... and finally I gave myself an answer: I have 2 pairs of AR2s with the super tweeter, I think the "magic" is because of him! I am convinced that I have two pairs of AR2s with one AR-ST !! Currently I do not miss a second super tweeter, the set of AR2a and AR2 seems perfect to me, but this one (I want to try) has been in the future for some time as I have all the components including the original canvas, only missing to exactly replicate the cabinet original (here the problem will be: where do I place it, above AR2 inverted or do I have to turn the speaker 180 °? At the moment I enjoy the two pairs like this. A final note for Norman Nicolai: I use three cork disks cut from bottle cork stopper under the stands and AR2a as anti-vibration material, instead a single cork disk of about 15 cm between Ar2a and AR2. in diameter and 1 cm. thick from Ikea very cheap: about 5$ for three pieces! No vibration or danger, I highly recommend this as proof. P.S. the AR18s currently not connected to any amp, with puppets are the head of my AR Totems! Quote Link to comment Share on other sites More sharing options...
samberger0357 Posted December 11, 2021 Report Share Posted December 11, 2021 Fantastic! I bet they do sound great. Now you just need an amp that will allow you to get down to 2 ohms so that you can run the 18's also. Quote Link to comment Share on other sites More sharing options...
lARrybody Posted December 11, 2021 Report Share Posted December 11, 2021 This amp will do 2 ohms easy. Crown XLS2502 Quote Link to comment Share on other sites More sharing options...
samberger0357 Posted December 12, 2021 Report Share Posted December 12, 2021 48 minutes ago, lARrybody said: This amp will do 2 ohms easy. Crown XLS2502 Yes it will, as what I use . But the Crown is certainly a lot easier to move around, a lot easier on the wallet, and a lot easier to find in the wild😁 Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 12, 2021 Author Report Share Posted December 12, 2021 8 hours ago, lARrybody said: This amp will do 2 ohms easy. Crown XLS2502 7 hours ago, samberger0357 said: ... The Crown is an option already taken into consideration by reading here the advice of several forumers, among other things also recommended by the Italian member Sonnar and a purchase of one of these amplifiers is planned. The second, the McIntosh Mc2300 is now a regret for me, I could have bought a nice example about ten years ago at a ridiculously low price, about 1000 $ current! I had given up then and even now I feel like crying: buying it is now impossible, the prices have gone up by several multiples and now, apart from a "stroke of luck", I always hope it is too burdensome for my finances ... in every case I have an amplifier that could be fine for this purpose, The Adcom-GFA555 currently stopped waiting for treatment, last time connected to my AR10TT "Replica" it gave out a spark inside, and one channel stopped working suddenly. But I'm not going to play the three pairs together, for the moment AR18 are just like a supermobile, they will play in another place in my house, with their own dedicated amplifier, I don't miss amps, indeed. My Adcom at rest ... in good company Quote Link to comment Share on other sites More sharing options...
samberger0357 Posted December 12, 2021 Report Share Posted December 12, 2021 The 2300 had a breakdown this year and I found somebody to come to the house to work on it. Mostly fixed it. Sounds great but has a bit of a hum that I can’t resolve. Can’t hear it when music is playing so I ignore it. These old pieces are great but once they break it can be difficult to find qualified folks to repair. I used to own the 555 and thought it was a great amp. I was mostly kidding about using the 18’s in your stack but they do look good on top of the pile. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 12, 2021 Author Report Share Posted December 12, 2021 Sam also in my case I have a lot of old electronics to be repaired or fine-tuned, apart from the Adcom I have an Italian power amp, the Monrio Cento* (this will be repaired, however, by the manufacturer factory with which I have already made arrangements) with mosfet transistors that will be dedicated with its pre to a pair of AR with 12" (circa woofers and unfortunately other electronics are waiting on the shelves to go back to "work" ... However your Mc2300 is the top for me and will always remain an unfinished dream, *I am attaching a link in which you see the test carried out in 1993 of this "dual mono" amplifier declared with 135w x 2 and with measured measurement of more than 280w / channel on 2 0hm! https://www.facebook.com/Monrio-795249060559803/photos/prova-monrio-cento-audioreview-maggio-1993/953843704700337 The text is in Italian, but in paragraph 1 you read the values measured at 8/4/2 ohm! good listening Quote Link to comment Share on other sites More sharing options...
samberger0357 Posted December 12, 2021 Report Share Posted December 12, 2021 Giorgio that Monrio is new to me but what terrific power it has! That must sound wonderful with the AR's. I try to only obtain gear that I know has been updated by either somebody reputable either recently, or the recent past. I completely stay away from anything less(or try to...in the end it ends up being an honor system much of the time unless a work invoice is available) because I have barely any electrical skill and there is barely anybody locally with skills that I would trust working on a McIntosh or other similar quality gear. But in the end, because of my bias towards older stuff, there is always a risk involved and I understand that going in. I do have a friend locally who buys and sells vintage gear as a trade, and so I can usually go to him not only for stuff to buy, but to unload things. I don't make top dollar doing this, but that's ok. Much easier then trying to list online, shipping, etc. While a MC2300 might be difficult to obtain, the same generation MC2100/2105, and the second generation 2120/2125 2200/2205 are fantastic amps with similar sound signatures, much easier on your back and slightly easier on your wallet and perhaps to find, and serve as more then suitable substitutions if they ever appear in your area. Quote Link to comment Share on other sites More sharing options...
frankmarsi Posted December 12, 2021 Report Share Posted December 12, 2021 6 hours ago, samberger0357 said: The 2300 had a breakdown this year and I found somebody to come to the house to work on it. Mostly fixed it. Sounds great but has a bit of a hum that I can’t resolve. Can’t hear it when music is playing so I ignore it. These old pieces are great but once they break it can be difficult to find qualified folks to repair. I used to own the 555 and thought it was a great amp. I was mostly kidding about using the 18’s in your stack but they do look good on top of the pile. "Mostly fixed it. Sounds great but has a bit of a hum that I can’t resolve. Can’t hear it when music is playing so I ignore it." That's a strong will, I guess. It must be killing you. You guys are lucky the site moral police haven't come down on you as they like to do with me. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 12, 2021 Author Report Share Posted December 12, 2021 32 minutes ago, samberger0357 said: a MC2300 might be difficult to obtain, the same generation MC2100/2105, Sam, I had an elderly technician, retired for years and very capable in repairing "ancient" equipment including those with tubes as well as old televisions, I lost the telephone contact I had, but I do not despair through common acquaintances to be able to contact him, he works well, I do not it is quick in the time it holds the item to be repaired, but it doesn't ask for a lot of money! Regarding McIntosh, I own (in addition to three Receiver Macs) the classic triptych C28, Mr77 and Mc2105, excellent, but the power amp now connected to AR10TT MK2 is too "small", I am attaching a photo taken a moment ago in which you see the amp and the tuner, above this, provisional the pre Monrio Primus instead of the C28 and, in the cabinet, in the right compartment the final Monrio Cento (in English Hundred) ... Quote Link to comment Share on other sites More sharing options...
samberger0357 Posted December 12, 2021 Report Share Posted December 12, 2021 Yes that's the problem with techs. The old one's are slowly leaving us, and there's very few younger folks who are interested in doing this kind of work. Lots of folks know how to do it, but few that do it for a trade. And who can blame them as it's long, involved work and with not much demand. Although the demand is growing as there has been growing interest in vintage electronics for some time now and people paying a lot of money for classic pieces like the Mac gear you own. My apologies for not knowing you owned so many great Mac pieces. Gorgeous! Are you saying that the MC2105 doesn't have enough power for your AR10's? That would be surprising to me. While officially it's 105 watts, my understanding is that it's more like 150 watts when tested. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 12, 2021 Author Report Share Posted December 12, 2021 13 minutes ago, samberger0357 said: the MC2105 doesn't have enough power for your AR10's? For the room where they are inserted, listening with the Mc2105 vu-meter indices at a peak of + three on the scale, therefore theoretically 100w. x 2 effective, everything is perfect, including the "magic" of being able to have a conversation between two people without shouting and hearing what the other person says! This happens with the combination in question and is hardly found with speakers of other brands ... but I notice that as soon as the AR10TTs wake up, with the Adcom (without the vu-meters), the sound pressure emitted by the speakers was certainly greater. , but always not annoying and the higher power easily tolerated without distortions or problems on the part of the AR10. On the other hand, I don't always listen at high volumes, the magic with ARs is also equal to tenths of a watt, everything still arrives perfect to the ear, much better than any headphones. Quote Link to comment Share on other sites More sharing options...
genek Posted December 12, 2021 Report Share Posted December 12, 2021 Positioning these speakers vertically is giving you a wide midrange dispersion... vertically. If you tend to stand up and sit down a lot in the same spot, that's probably great. Not so great if you ever intend to leave the single location your horizontally beamy speakers are optimized for and move around the room. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 12, 2021 Author Report Share Posted December 12, 2021 1 hour ago, genek said: horizontally beamy speakers are optimized for It's true Genek I miss enjoying the horizontal positioning for which these speakers were designed, but this position, as seen in the photos, is forced by the size of the wall and the 4-door sideboard in the middle of the speakers. Less horizontal dispersion partly mitigated by the not too great distance between the speakers ... unfortunately you can't have everything. I had been able to listen to a pair of AR3a horizontally positioned for some time, but in this case the different positions have little change on the mid-high range dispersion. However, now I enjoy the double pair like this and I thank mom AR for "cheap" instruments of about 60 and more years that today, 2021 cheer me up with pleasant sounds and it is an extraordinary thing, nothing to do with the strange and expensive speakers produced today and designed not to reproduce sounds, but to adapt to market demand: they are fine today, tomorrow I have to change them to adapt to the new way of listening! Maybe it won't be tomorrow or next year, but the AR2a, due to the help of the supertweeter and don't forget that I also own an additional pair of Heathkit AS-2a, so I can double the AR2s too eh, eh ... they will have to be placed in the other room where they can play as they were designed, horizontally; this is not a dream but a project that I will realize. The only lack, impossible (never say never) to be able to insert them horizontally in the library and surrounded by books! Before publishing the answer, I search the archive for a photo of one of the two AR2a with the original canvas (there are all four AR2a and AR2 canvases plus an AR2a spare part that will serve as a donor to make the AR2-ST canvas), made years ago , before restoring the couple and then placed between two boxes in the closet. In this speaker the pin "a" is missing, then purchased in the USA! Giorgio Quote Link to comment Share on other sites More sharing options...
ar_pro Posted December 12, 2021 Report Share Posted December 12, 2021 7 hours ago, samberger0357 said: The 2300 had a breakdown this year and I found somebody to come to the house to work on it. Mostly fixed it. Sounds great but has a bit of a hum that I can’t resolve. Can’t hear it when music is playing so I ignore it. These old pieces are great but once they break it can be difficult to find qualified folks to repair. I used to own the 555 and thought it was a great amp. I was mostly kidding about using the 18’s in your stack but they do look good on top of the pile. The hum might be a power supply issue, Sam...is it in both channels? I'm not sure what the life expectancy is for those large supply capacitors, but I'd suggest giving the folks at Audio Classics a call - they have extensive experience, and might be able to suggest a more local service solution, should you not want to send that monster to New York. Several years back, my wife & I took a trip up to Binghamton with a Mac amp that was having a problem, and AC fixed it while we waited. They also set us up for a personal tour of the McIntosh factory, which was very exciting! They're great guys to work with. Quote Link to comment Share on other sites More sharing options...
ar_pro Posted December 12, 2021 Report Share Posted December 12, 2021 4 hours ago, Giorgio AR said: Sam, I had an elderly technician, retired for years and very capable in repairing "ancient" equipment including those with tubes as well as old televisions, I lost the telephone contact I had, but I do not despair through common acquaintances to be able to contact him, he works well, I do not it is quick in the time it holds the item to be repaired, but it doesn't ask for a lot of money! Regarding McIntosh, I own (in addition to three Receiver Macs) the classic triptych C28, Mr77 and Mc2105, excellent, but the power amp now connected to AR10TT MK2 is too "small", I am attaching a photo taken a moment ago in which you see the amp and the tuner, above this, provisional the pre Monrio Primus instead of the C28 and, in the cabinet, in the right compartment the final Monrio Cento (in English Hundred) ... That's definitely a classic combination, Giorgio - I think the MR77 is my all-time favorite FM tuner. Having the original walnut cabinets is great - especially for stacking, but I still enjoy seeing Mac equipment au naturel ! Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 12, 2021 Author Report Share Posted December 12, 2021 8 minutes ago, ar_pro said: but I still enjoy seeing Mac equipment au naturel ! True, the charm of the naked McIntosh is unmatched, even the four "feet" that hold them slightly off the ground have their charm, like a beautiful and elegant woman with little clothes and high heels Quote Link to comment Share on other sites More sharing options...
giovanni56 Posted December 13, 2021 Report Share Posted December 13, 2021 8 ore fa, Giorgio AR ha detto: Sam anche nel mio caso ho molta vecchia elettronica da riparare o mettere a punto, a parte l'Adcom ho un finale italiano, il Monrio Cento * (questo verrà riparato però dalla fabbrica del produttore con cui ho già preso accordi) con transistor mosfet che sarà dedicato con il suo pre ad una coppia di AR da 12" (circa woofer e purtroppo altra elettronica aspettano sugli scaffali per tornare a "lavorare"... Comunque il tuo Mc2300 è il top per me e resterà sempre un sogno incompiuto, * Vi allego un collegamento in cui è stato effettuato il test nel 1993 di questo amplificatore "dual mono" dichiarato con 135w x 2 e con misura misurata di oltre 280w/canale su 2 0hm! https://www.facebook.com/Monrio-795249060559803/photos/prova-monrio-cento-audioreview-maggio-1993/953843704700337 Il testo è in italiano, ma nel paragrafo 1 si leggono i valori misurati a 8/4/2 ohm! buon ascolto L'Adcom GFA555 ha fusibili in vetro, quattro, interni al case sulle schede dei transistor finali, sono 6.3A, posti sui rami di alimentazione cc. Si attivano per sovraccarico e cortocircuito, ma anche per un guasto su un transistor driver o su un amplificatore di potenza. Se hai visto un lampo e un po' di fumo durante il guasto, significa che probabilmente si è bruciata una resistenza da 300 ohm 1/2 W sulla scheda di ingresso dell'amplificatore, ma potrebbe essere che un transistor finale si sia guastato. Quote Link to comment Share on other sites More sharing options...
samberger0357 Posted December 13, 2021 Report Share Posted December 13, 2021 6 hours ago, ar_pro said: The hum might be a power supply issue, Sam...is it in both channels? I'm not sure what the life expectancy is for those large supply capacitors, but I'd suggest giving the folks at Audio Classics a call - they have extensive experience, and might be able to suggest a more local service solution, should you not want to send that monster to New York. Several years back, my wife & I took a trip up to Binghamton with a Mac amp that was having a problem, and AC fixed it while we waited. They also set us up for a personal tour of the McIntosh factory, which was very exciting! They're great guys to work with. Turned out it was being caused by my Allison Electronic Subwoofer, which I had connected between the amp and preamp. Whether it was too close to the amp, or the amp just didn't like being connected to it, or the IC"s, something was not copacetic between them. So it is now connected in the preamp's(McIntosh C11) tape loop and the hum is all but gone. I had a board fry several resistors a few weeks ago and just had that repaired so it sounds great, but it's never been the most quiet of all amps. The amp had supposedly gone through restoration before I bought it, but I didn't have anything to prove that other then the seller's word and the description of what he did. I took a shot, and it performed very well for several months until the last issue. I bought my C11 from AC but this is one piece they won't be able to help me with. There's one local guy that has a good rep, but I would still have to schlep the amp to him. I got a fellow who has been repairing audio gear for several years to make a house call, and while he comes from an EE background, he's not a Mac expert. But he removed the board, brought it back to his place, replaced the burnt/bad parts, returned and installed. Obviously it would've been great to have an expert be able to get this thing on the bench and give it a complete overhaul but that's out of the picture. The next time(if there is one) it goes down I'll probably just sell it. I'm hoping that because it's a tank, and rugged as hell it will last for at least awhile more. I have a nice MC2120 that I bought locally that was worked on by Terry Dewick in 2014(I have the invoice) and I'm using that now to drive my AR3's, while the 2300 drives my Allison One's. And yes, the speakers are stacked and amps are used simultaneously. Damn nice sound. Quote Link to comment Share on other sites More sharing options...
ar_pro Posted December 13, 2021 Report Share Posted December 13, 2021 Ah, a processor in the chain was the problem - this makes sense. I've never owned a 2300, but I understand them to be extremely rugged, and - except for the incredible weight - a bit more service-friendly than the domesticated, glass-fronted models from Mac. The service manual is online, and I've read that the amp has a single chassis ground that should be checked for tightness. The MC2120 is another great amplifier. I purchased a preamp directly from Terry a long time ago, and his work on Mac equipment was always first-rate. Quote Link to comment Share on other sites More sharing options...
dxho Posted December 13, 2021 Report Share Posted December 13, 2021 8 hours ago, Giorgio AR said: It's true Genek I miss enjoying the horizontal positioning for which these speakers were designed, but this position, as seen in the photos, is forced by the size of the wall and the 4-door sideboard in the middle of the speakers. Giorgio I'm sure you know this, but is it worth considering replacement of the dual mids with the 2ax midrange? Upgrade the sound and address the dispersion issue at the same time. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 13, 2021 Author Report Share Posted December 13, 2021 3 hours ago, dxho said: considering replacement of the dual mids with the 2ax midrange? When I bought the AR2a, a dual mids section had the coils of both speakers burned out, I had considered replacing the dual mids years ago before knowing this Site and I had built a flange at the time to insert a Heco mid ... it was not the same thing. Then I found a spare and as you can see in the photos of the AR2a, now they have in every dual mids basket a speaker with a brown and a gray cone (the gray ones are the most common, it seems that the brown paper was produced for a short period. only 1963, year of my speakers), never found spare parts with brown paper, too rare ... so I leave my AR2a, even if later I bought another dual mid as a spare, always with gray paper, it may be that I can to serve! I also own AR2ax and 2 pairs of spare mids, but now I don't want to use them with older sisters, I like them that way, but I always hope to find a dual dome with brown cones !! Help me ... Here is the photo documentation below 8 hours ago, giovanni56 said: visto un lampo Only flash and immediate attenuation of the left channel, the amp turned off and placed on the shelf. I'll send you a PM! Quote Link to comment Share on other sites More sharing options...
dxho Posted December 13, 2021 Report Share Posted December 13, 2021 Like this? Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 13, 2021 Author Report Share Posted December 13, 2021 12 hours ago, dxho said: Like this? Ouch, how much harm it does to me ... unfortunately from Italy it is more difficult to find spare and exact parts for old "objects" ... It was better not to see. I am attaching a thread, published some time ago on the disassembly (I would have hoped to find some easy problem, but look at the burns of the coil support) of one of the two non-working "brown paper" dual mid cones and still preserved !! Another small clarification on these particular mids, the couple photographed of me that you see in the posts above arrived intact, but if I'm not mistaken on CSP, years ago there was a topic about a dual mid that had arrived after shipping packed and wrapped. in nylon and this had stuck tenaciously to the sticky substance on suspension unfortunately tearing the paper itself of the cones !! For those who buy a pair of mids in its plastic container (they appear together every now and then on E..y), the best method of protection is illustrated below, minimum fatigue, maximum protection: double-wave cardboard (better two), paper tape and then any packaging can be done: the objects will arrive perfect, even in Australia! Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted December 14, 2021 Author Report Share Posted December 14, 2021 Still a little advice on the AR2 / AR2a mid cones, the paper of the cone is very thin and fragile, furthermore pushed outwards by the fiberglass triangles present at the rear between the cone and the frame, and sometimes has more cuts on the cone extended or not! It also happened on the cones of my AR2a, under the well executed photo and circled some of the cuts detected at the time (the other cuts can be identified well ...), repaired as follows: Removed the speakers, carefully removed the four fiberglass wedges, approached to match the edges of the cone paper, cut small pieces of thin tobacco paper and glued on the fracture line behind the cone, at the front, with a toothpick passed a small glue lip on the same fracture lines. Reassembled after drying, the mids have been playing perfectly for years. Quote Link to comment Share on other sites More sharing options...
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