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  2. Nice catch! The pots probably need cleaning. I use vinegar to get in all the crevices, then a Dremel or some such if the corrosion is serious. Capacitors will quite likely need replacement, too. Yes, RoyC sells the sealer for the cloth surrounds. The seal on yours looks a little worn out, so they could probably use a treatment. I use GooGone or GoofOff, some variation of citrus-based cleaner for adhesive like on your cabinets. Toluene would be a last resort as it would take wood finish off, too. I've used various combinations of ARs. Right now my main listening station is two pair of AR-3a.
  3. Today
  4. Hi, Ever since I finished the restoration of my AR 2ax's, with great help from the people on this forum ( thank you all!) I've been wanting to get my next pair. My chance came - a couple was selling a pair of AR-4x speakers on CL for what seemed to me like not that much money, considering they seemed to be in pretty good shape. My main concern was that they still had the original drivers, all working. Their original photos didn't show them with the grills off, in fact they didn't realize the grills came off and that people might be interested in seeing what's underneath. When I emailed them to ask if they still had the original drivers, they said 'what's a driver?'. I could tell they thought the speakers sounded bad, even though they didn't come right out and say it. I speculated that scratchy pots with dead spots were probably the culprit, and I know how to deal with that. I met them and I told them what I know - I'm not really a wiley person by nature. It's not clear how much they cared. They were glad to sell them. Wow, do they sound great. I wiggled the pots when I got home and those tweeters burst alive. The cabs aren't nearly in bad shape like my AR 2ax's - a little light restoration and they'll be fine. I do have some questions. 1) I learned how to refoam woofers (thank you Roy!) but these have the cloth surrounds. How do I evaluate the condition of the surround and determine if it needs any treatment? And if it does, what should i use? I know people here have talked about some substance that Roy and others use. 2) The previous owners put little round sticky feet on the cabs. I peeled them off and there's adhesive residue. Not serious but as a first step I need to clean that off. What do you recommend? Mineral spirits? Tuoluene? 3) I think these speakers sound good in combination with my AR 2ax's. Are there particular combinations of different AR speakers that people like? I'm guessing there are. Rob
  5. I see your point, ra.ra, and agree. AR simply added another 6uf cap in parallel with the original 24uf side of the dual cap to make 30uf...same outcome. As you suggested, it was probably easier to add the 6uf cap to the original crossover scheme in this way, rather than change the original wiring. In the past few years I haven't been noticing the details... just removing and replacing the dual cap, and associated nest of wiring, with a new single (era dependent) 24uf or 30uf cap, and 6uf cap (along with the pots). In spite of the original dual caps, and the discussion above, the 3 is really an easy model to re-cap. Of course to make it more interesting, Jeff's specimens are the first AR-3's I've seen using one half of a dual 6uf/2uf cap. AR must have been clearing out the parts bin to slap these later 3's together. I believe AR was offering the AR-3 to AR-3a "upgrade" about this time, so the 3's days were numbered. Jeff, I'm looking forward to learning the inductor values! Roy
  6. I reopened the cabinet this morning to get more detail on the crossover. lakecat and Robert are correct that there are 2 wires coming out of the small cap block and that the unused value was not blackened out. The other cap is a dual 24 / 6 microfarad unit. So, as Roy and Robert guessed, this crossover looks like the AR-3 crossover schematic posted yesterday with the small block cap wired in parallel to the 24 microfarad section of the dual cap, giving 30 microfarads for the mid. The coils appear to be the same. I plan on taking them to work with me on Monday to measure them with an LCZ meter. Referencing the 'Rebuilding the AR-3a' document, the woofer appears to be the A.2 and the midrange the A.12. The tweeter looks and sounds like its in good shape with only some surface rust on the plate. Geoff, I wish I knew the history of these. My guess is that they were ordered directly from AR in 1971. The first picture in my original post is the picture the estate sale company posted one day previous to the sale. From the shape of the cabinets I would guess they had sat in the basement for some time. One of the employees of the estate sale company said that they had filled a dumpster with stuff, including speakers, and hauled it away previous to the sale. Luckily AR-3's are heavy and they probably didn't want to carry them out of the basement. Better to let me pay $25 for the privilege! Glenn, I threw in some cabinet pictures. What's the best way of dealing with the split edge seams?
  7. Hi Kent, In my opinion, the smoother response of the alnico woofer makes it more flexible, so it works at least as well as the later woofer when used with the larger coil. If they were mine I wouldn't swap it out for the smaller one. An advantage of the larger coil is the ability to use either woofer. Roy
  8. For anyone interested I just acquired an early , 2 motor XA, serial number TX 12477. Got it with the original dust cover, too. I have already an XA that is several years later, serial number XA 85954. Here's some pics of the early one.
  9. Roy, I agree that the hidden cap under the coils is most likely the dual 6uF/24uF, and I also agree that the wiring scenario you suggest (combining in parallel the 6 and 24 of the dual cap to make 30 for the mid) would be a more sensible arrangement, as shown in the proposed schematic shown here that I cobbled together for this post. However, that is not how the crossover shown by JeffS has been wired - - in fact, it appears to have been wired exactly like the schematic I showed in a previous post. If you look closely in the x-o pic, from the dual cap you see the green (24) wire attach to the mid pot, while the black (6) wire goes to the tweeter pot. These two caps have not been combined in parallel. Regardless of which wiring scheme was implemented, the results would be the same for the speaker performance, but it's kind of silly to take the normal dual cap, split off the 6uF for the tweeter, and then add another 6uF cap to boost the mid value to create 30uF. As you have suggested and I have sketched (below), it makes far more sense to simply have one wax block cap per driver. Although the wiring is a bit cumbersome IMO, it is easy to understand why it might have been done this way, and that is because the two crossover components (6uF cap and 0.4mh coil) required to accommodate the AR-3a mid were simply viewed as mere additive items to the previous AR-3 (version C) crossover that the assembly line was already used to cranking out. And to correct my earlier statement, I think there are actually seven wires connected to the mid pot tabs: (2) green to #1 tab; (2) yellow and (1) coil to #2 tab; and (1) green and (1) coil to 'B' tab, as seen in crossover photo supplied by the OP.
  10. Interesting stuff (well, maybe only to AR geeks like us). Going off on a slight tangent, here's a question for you, Roy. You wrote You're familiar with my ar-3/3a conversion but to briefly recap: They were 3s but I could only salvage the cabinets and cloth-surround woofers. You provided some very nice AR-11 mids and I used the Hi-Vi tweets. The crossover was pretty much built from scratch as a late AR-3a xo. The only mod IIRC was the addition of a series cap to the tweeter. I'm using the #9, 2.85mH woofer inductor. Should I swap that out for something smaller? -Kent
  11. That's a big help thanks so much.
  12. this been an older post, I may be out of place reviving. Then again I only signed up cause soundminded answer is very helpful. Anyways thanks, got some good gouge out of your reply post.
  13. ra.ra, The AR-3 crossover is much simpler than the 3a crossover, and the 6uf tweeter cap is the only capacitor common to every iteration of the AR-3 and AR-3a. I'm pretty sure the dual cap under the coils is the usual 24uf/6uf AR-3 capacitor, wired in parallel to make the 30uf cap for later mids. The 3's dual midrange cap was originally used as a 24uf cap for the mid and 6uf cap for the tweeter. When the change to 30uf was required it was simply wired in parallel, and a second 6uf cap was added for the tweeter. (I've seen AR-LST crossovers using a combination of 20uf Sprague caps and older 10uf Industrial Condenser wax block caps to make its 30uf midrange crossover cap.) The original AR-3 crossover places only a .4mh coil in series, and no parallel capacitor with the woofer, vs the 3a's 1.88mh or 2.85mh series coils, and large 150uf parallel capacitor, so the AR-3's electrical crossover was much more gradual for the well behaved alnico magnet/cloth surround woofer. The ferrite magnet/foam surround woofer is not as smooth at higher frequencies, which is the reason for the 3a's change to the larger (2.85mh) coil when it began using this woofer. I'm curious if we will find a larger coil value in this pair to provide a steeper cut off for the later woofer. Roy
  14. Nice, I have the same ones.
  15. The driver in the AR-3st is the same red dome tweeter used in the AR-3, AR-2a and early AR-2ax.
  16. Rare AR-3 st super-tweeters. Does anyone have a replacement tweeter for this and is this an Alinco? Thanks
  17. this is such a great thread, and find. Was there any known history? I assume one owner specimens. more updates to the guide
  18. Yesterday
  19. If memory serves me correctly, the AR5 was not yet available at the time of the Holt article and I believe that the references to AR5/AR5a, etc., are transcription errors that did not appear in the original report. I think he was actually referring to the AR2 & AR2a. I have the original Stereophile article somewhere (as well as the CR loudspeaker article mentioned by Tom) which I will try to find to help sort this out.
  20. I am not familiar with the intricate details of the AR 3-series iterations the way so many of you are, but the most surprising thing to me is to know that there was a late version AR-3 being factory supplied with a foam-ferrite woofer - - - total news to me! We all know about the early model 3a's that were assembled with the cloth-alnico woofer, but I don't think I've ever seen this permutation presented or discussed. Good question from Roy about the coils - - - they appear to be marked "2" and "3", but it almost looks like they have a similar amount of wound wire under the spool. Presuming that it is a dual cap under the coils, I would assume that a modern re-cap would result in a slightly simpler wiring scenario, with just a single (or multiple to total) 30uF cap for the midrange driver. Geez, are there six wires attached to that mid pot? But.... if this AR-3 speaker is using LF and MF drivers from the 3a, it is a bit curious that this value is not the more typical 50uF found in the 3a.
  21. This is a great find, indeed! It is my first glimpse at the innards of the last iteration of the AR-3. With confirmation that only the 6uf leg of the dual cap was used, my last question would be what the inductor values are. The "end of production" AR-3 schematic from the CSP Library posted by ra.ra shows them to be the same (.4mh), but it appears this may not be the case. It also dovetails with a recent discussion I've been having with Tom T. regarding the extent to which the alnico woofer was in use after 1970. The ferrite magnet woofers in the photos above have the same 1971 date as the other drivers, and are consistent with the "long" voice coil leads found in 1971 era woofers installed in AR-3a's of that era. I have little doubt these are original to the cabinets. I wish we had the cabinet serial numbers. The nice thing about this iteration of the AR-3 is that it does not have the original style midrange(s) with the increasingly common "petrified dome suspension" issue. Roy
  22. Re: caps, I suspect that Roy's thoughts are touching on both curiosities. It appears that the 2uF portion remains unused but was not blacked out, which was typically done (see pic attached) when a cap section was abandoned. Also, it looks like the large cap is quite possibly a dual 6uF/24uf cap, as shown in late AR-3 schematic. (Also, almost forgot to to say "great find", and I love that pic of the basement.)
  23. Odd that the cap says the 2uf is a black wire yet I don't see a black wire coming out of that cap.
  24. Wow . . . congratulations!. it doesn't get much better when it comes to curbside finds. Been there (and it feels really good!), with a pair of AR-11s found curbside a few years back. Just needed new woofer surrounds.
  25. so yes I did get a closer look at these and they are wonderful. Pots are rough as you would expect but no evidence of ever being opened! Also I am just not sure where this will all go. While the current owners understand these are holy grail kind of stuff, they are not using them as anything but speaker stands for a small set of NADs. We have not really done any negotiating but they understand I am an AR enthusiast. My sense of this is they hold more sentimental value than monetary. While there the husband also referenced an old AR turntable in the basement that he has envisioned resurrecting but he lost his hearing and with that has lost interest in audio related things. They have boxes and boxes of old tubes and caps from the past (also part of the inheritance booty) as the Uncle was a tube radio guy as well. I will keep this updated as things unfold, if they do. I love this old grille material.
  26. I'll try to provide more crossover detail this weekend. I did get a few minutes to check the drivers and they all work, however the pots don't. That made me happy as there were a lot of low to medium power receivers (70's to early 80's) at the sale that could have blown these tweeters.
  27. Good question, and I have to admit this was a purely subjective test. I never ran a frequency response curve on the A-25 in order to do a true "apples to apples" comparison with my ARs. But the roll off below 50hz must be much steeper than the typical acoustic suspension speaker. While it is true that the A-25 is a 10" design, its magnet is smaller and lightweight when compared to AR 8" woofers. Its excursion range is less as well. Again, I'm not disparaging the A-25 - it is a fine speaker. It just doesn't deliver quality low bass when compared to AR's even most modest models. Also, "sins of omission" at frequency extremes are far preferable to a speaker which adds higher harmonics when it can't reproduce fundamental frequencies.
  28. Not sure, guys...I have not worked on many post 1970 AR-3's, and these appear to be just that. The drivers' date stamps suggest they are late AR-3's, which were equipped with the later ferrite magnet/ foam surround woofer and the 3a type of mid. Other than an additional .4mh coil across the mid, which appears to be present, the crossover should be much like earlier versions (check out the drawings showing various iterations of the AR-3 crossover in the CSP Library). These specimens actually look very original to me, with no obvious signs of non-AR tampering. I would love to get a closer look at the capacitor connections and the values printed on the larger cap. I'm wondering if only the 6uf leg of the smaller dual cap is connected. If not, I have no idea what the role of the 2uf leg is. If these are all original, and I believe they are, it suggests the alnico woofer was no longer being used in the AR-3 in June of 1971. Tom should be along any minute. Roy
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