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r_laski

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About r_laski

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  1. Really great post Steve. >>They were in truly excellent shape, the 12” and 8”-ers re-foamed with care and the x-o re-capped correctly. (The previous owner is an MIT electrical engineer.)<< I was wondering if you could elaborate on the x-o recap. I have 4 AR-9’s (possibly 6 if my brother wants his done) I’d like to recap, but not run into any problems other forum members have indicated they had with recapping their AR-9’s. >>I’ve enjoyed all of them and they all have their particular charms. There is a dividing line of sorts, between the sound of the 11’s and the sound of the 91’s, to my ear. Old and new. The 11 was more closely related to the sound of the 3a than it is to the 91 and 50t, in my opinion.<< I completely agree with what you are saying about a dividing line between AR-11 and AR-91. >>It is definitely NOT merely an “11 with more bass.” The 9 has a striking midrange clarity and utter command of the material such that the listener is really “listening through” the recording, right to the performance itself (at least on good recordings). No doubt the speaker’s 4-way design and the 8” driver’s 200-1200 Hz role has a lot to do with its complete lack of midrange strain and coloration.<< Absolutely correct. You might be able to say the AR-9 is an AR-91 with more bass. But, it is more correct to say the AR-9 is an AR-90 with more bass. Also, The AR-9 is a completely different era of speaker from the AR LST, another AR “tour-de-force” speaker. >>Assuming no amp-induced distortion (and with 385 wpc RMS in my modestly-sized room, there isn’t any), the 9’s just never run out of steam. You find yourself playing things a bit louder than usual just because everything is always so darned clean. When the branches of a decorative artificial tree in the corner were literally waving in the breeze, I knew the 9’s were really cranking. But sweetly.<< Crank it up!! The 9’s will not disappoint. One thing I found with LST’s vs. 9’s is the LST’s needed a lot more power to "come alive" than the 9’s. Like the AR-11 vs. AR-9 you really can’t compare the “sound” of the AR LST to the “sound” of the AR-9. Both are outstanding speaker designs. They just present the soundstage to the listener differently. >>That so many jaws still continue to drop upon hearing them (including mine!) 30+ years after they came out, says it all.<< Amen. I enjoyed reading your post. Rich
  2. Mike, Here is a picture of an original AR-11B crossover. If yours looks like this, its all original. Based on your visual inspecton, I'd recommend you replace the caps (even though you can't measure them) and leave everything else alone. Rich
  3. >>I found single Solen capacitors at exactly the 120uF capacitance at Madisound. Seems a good way to go for not too much to avoid having to parallel others.<< A single Solen cap is a very good way to go. >>Also, the foam surrounds for my tweeters are in fairly good condition. Would you suggest I leave them alone for now or consider the felt surrounds offered by Vintage AR?<< If the foam is not dried out and turning to dust, or, turned into a sticky, goo - leave them alone. I had to remove the tweeter foam on my AR-11s and I just left them "naked" like the earlier AR-11A's were. >>Gee, I really appreciate everyone's help. I've listened to today's speaker technology on the market and I cannot find anything below $6,000 with my ears and preferences that compare to our AR's.<< I know what you mean!! Good Luck restoring your AR-11s Rich
  4. Comment on AR-11 schematic: This is a VERY early schematic. As Tom Tyson noted, I’m not sure the 2 amp fuse was ever included in production AR-11s. I’ve never seen an AR-11 with the fuse. Also, the parallel 72uF and 50uF caps were replaced with a single 120uF cap in the woofer section – silver Callins can – when the AR-11 crossover was reconfigured from a 2 board to a single board crossover. Mike, Since you purchased your AR-11s in 1978, I’m assuming they are what we refer to as “AR-11B” –black/silver badge and foam around tweeter. I purchased mine that same year. If you remove the woofer look at the crossover for burned resistors (blackened hot melt glue between resistor and board it’s attached to). If glue is still white, the resistors should still be good. The inductors and wiring should also be OK. Have the caps individually tested. They most likely are due replacing as Kent has stated. 10uF and 40uF caps are readily available. You may have to parallel 2 or more caps to get a 120uF cap. I’ve had good experience with Solen caps, not so good experience with Daytons. I haven’t tried Bennic or Carli caps yet. Your amp/AR-11 combination should work well in a ~ 12X15 room. At “sensible” volume levels you will have little risk of amp clipping and damage to your AR-11s. I’ve powered my AR-11s for years with 300 wpc into 4 Ohm amps with no damage. Hope this helps
  5. >> It seems like if you pulled all four wires off the switches, you would basically be connecting them all together to bypass the switches. So if I take a piece of solid copper wire and crimp and solder on 4 flat lugs to match the size of the slip on connectors already on the wires, and bend them up at a 90 degree angle to the wire, i could make a connection that would allow me to use the existing wires as is and just move them back and forth to A/B with and without the switches. I could mount this to a small piece of wood to create my own terminal strip. Does that sound right to you? Thanks, Bob << A homemade terminal strip. That would work. Rich
  6. >> My original plan is to recap only one speaker at first to see how much of a difference there is. ... I'll probably leave the switches at first to just hear the difference of the recap alone. << Leaving the switches in after recapping is probably a better way to go. I could have written my recommendation either way. If you find you don't ever use them after an adequate period of listening you can always go back in and remove the switch board wires and connect wires/capacitors as I described for bypassing the switches. >>If I want to clean the switches, can I just squirt in some DeOxit through the slot from the front without removing anything? I didn't want to remove the board their mounted on and can't see anything with it in the way.<< I think that will NOT work. A few years ago, I took apart a similar switch (AR-11). They are well sealed. All you will be cleaning is the ball at the end of the toggle handle, not the inner workings of the switch. If anything, you want to spray the contacts where the switch is soldered to the switch board. Rich
  7. >> If I want to bypass them, how do I hook up the 4 wires going to the board (from front of speaker L to R -- purple-orange-white-yellow) Does anyone have a diagram of how to hook them up to bypass the switches? They have lugs on them and I don't want to cut them (so I can easily re-attach them) Sorry for all the questions, but this is my first speaker recap, and I want to be sure of what I'm doing before I start. << Bob, Regarding bypassing the switch board - 1. The long white wire is connected from the UPPER red binding post to the switch board. You can disconnect this wire at the binding post or remove this wire to bypass the switch board. You can also disconnect the other three wires at the switch board (easy) or desolder them where they attach to the original capacitors (a little more difficult). 2. You must then run wires from the upper red binding post to the capacitors of the lower midrange, upper midrange, and high range crossovers. A. Run a Yellow wire from the upper red binding post to where the yellow wire that comes from the switch board attaches to the 4uF capacitor of the high range (tweeter) circuit. Or, since you are replacing the capacitors, attach one lead of the 4uF capacitor directly to the upper red binding post. B. Run an Orange wire from the upper red binding post to where the orange wire that comes from the switch board attaches to the 24uF capacitor of the upper midrange circuit. Or, since you are replacing the capacitors, attach one lead of the 24uF capacitor directly to the upper red binding post. C. Run a Violet wire from the upper red binding post to where the violet wire that comes from the switch board attaches to the 80uF capacitor of the lower midrange circuit. Since this capacitor is on the bottom board, you will have to run a wire from the upper red binding post to the 80uF capacitor. 3. You should be able to figure out a way to do this that is reversible so you can put the switch board back into the crossover circuit. I recommend you recap and bypass only one speaker and test it against your other speaker before you make any modifications to it. You can then compare an "original" AR-9 with a "recapped/bypassed" AR-9. If you don't like it bypassed, reconnect the switches and compare your "original" AR-9 with a "recapped only" AR-9. As Richard mentioned, you may find the switches necessary with the new caps. Rich
  8. " I had a quick question. It looks like the most important of the resistors is the 6 ohm 22 watt. The others are part of the switches to reduce output, and since I've never used them, I'll probably bypass them anyway. I was going to get some replacements for the 6 ohm but the closest I could find is to put 2 - Mill's 12 watt 12.5 Ohm (from P.E.) in parallel to get a 24 watt 6.25 ohm. I'm mot sure how critical the value is in a crossover. Would the 6.25 ohm be close enough to 6?" IMHO - I'd measure the 6 Ohm resistor. If it measures OK - don't replace it. The sand cast resistors AR used are very rugged and don't usually require replacement unless the speakers have been overdriven and the resistors overheated. If you have to replace it, consider the 25 watt sand cast resistors from Madisound. A 2.7 Ohm and 3.3 Ohm in SERIES (not parallel) will get you the 6 Ohms you are looking for. If you do replace the 6 Ohm resistor, I recommend you elevated the resistor(s) above the board by bending the leads. This allows cooling space between the resistor and the board reducing the risk of overheating the resistor. I'm very interested in how your project turns out and results of any subjective listening tests you do between stock/recapped AR-9s. Rich
  9. Aleksandar, --… What are the differences between these speakers and the later versions with black front badges and Teledyne front stickers?...-- One “non-cosmetic” difference between the brass logo AR-11 and the black/silver logo AR-11 is the diffraction foam on the faceplate of the tweeter. There is one thing you need to look at with the brass logo AR-11s: Look at the binding posts and the attenuation switches on the back. If the switches are above the binding posts you have a single board crossover. If the switches are to the side of the binding posts you have a two-board crossover. The two board crossovers were only in the very earliest AR-11s. Since the cloth of the tweeter is black and not an off-white color, I suspect the AR-11 in the picture is not one of the earliest AR-11s produced. The single board crossover used the same components in the brass and black/silver AR-11s. The two-board crossovers used different components and the attenuation switches are wired much differently. I posted pictures of these somewhere on this forum. When I restored a two-board AR-11 I changed the attenuation circuit to the later “version.” --…Any difference in sound beside the cosmetics?...— Steve F wrote: “My gut feel is that you could have a stereo pair of one brass-logo'd 11 and one black-and-silver plastic logo'd 11, and (assuming they were both operating properly, within AR's production QC spec) never hear anything amiss.” I totally agree with Steve. The components used were essentially unchanged between the two versions with the single board crossover. I am also in complete agreement with Ken Kantor’s statement in a recent discussion on the AR-10pi, “In my opinion, the addition of the foam to the tweeter faceplate was not a particularly good idea.” In my opinion, once the foam on the tweeter starts to disintegrate, the best thing to do is completely remove the foam and adhesive from the tweeter faceplate. I have done listening tests with both black/silver logo and brass logo AR-11s single and two-board crossover versions (and written extensively about them in this forum). They sound equally bad with “out-of-spec” capacitors and equally great with “in-spec” capacitors. I cannot hear any sonic effect of tweeter diffraction foam. I do not claim to be a GESR (golden eared stereo reviewer) either. --…He painted the woofers with some special liquid that restores and reinforces driver cones. This is why they are so shiny. What is your opinion on this? Can this have some influence on the sound, making it different than original (changing resonant frequency or something like that)?...-- I’ve done the same thing on a few woofers I’ve re-foamed. I can’t say I “hear” any difference by doing this. I think it is really not necessary and can’t recommend it as a sonic improvement to the woofer. But, I also don’t think it would significantly change the “sound” of these AR-11s or their value. --…And most important, he is thinking of getting at least 500 Euros for the pair. This is 635 US$. This price seems to be too high to me. What do you think? Do you know what is the average price they usually go for?...— I haven’t monitored AR-11 auctions on e-Bay in a long time. Even so, winning bids vary widely. Things to consider are the condition of the cabinets, condition of the drivers, and whether or not the original foam grills (in good condition) are included. Original boxes and packing materials and documentation can also bring a premium price for a pair of speakers. Regardless of the above, if your friend hasn’t already done so, the capacitors in these AR-11s will most probably need to be replaced. That has to be figured into what one is willing to pay for these speakers. What I think -- $635 is probably what your friend paid for his AR-11s in the ‘70s, assuming he is the original owner. If your friend is selling his AR-11s as pictured, the price seems too high to me too. Mint condition cabinets, re-foamed woofers, with no grills, or other items to go with the speakers, I think $200 US +/- may be closer to a ballpark asking price. But, even that may be an ambitious asking price in the current economic environment. As Steve posted, "Value, like beauty, is indeed in the eye of the beholder,..." Hope this helps. Rich
  10. I received a request from a forum member for some pictures of AR-11 crossovers I rebuilt that are no longer available in my previous postings since the overhaul of the forum. I've attached them here to share with all forum members. Hope they help anyone recapping their AR-11. Rebuilt AR-11 Single board crossover. Original two-board AR-11 crossover. This is the only picture I could still find for this crossover rebuild. The woofer caps are not shown. They are located at the front of the bottom board. This one's for you Klaus Rich
  11. >>I think I'll replace the old caps with some Dayton caps from partsexpress... unless there are any big objections?<< Not an objection, but a warning and a recommendation. I tried using Dayton caps in an AR-90 crossover. I did not like the results at all. To me, they sounded no better than the out of spec original caps when I conducted a subjective listening test of a Dayton recapped AR-90 against an originally capped AR-90. I replaced the Daytons with Solens and North Creek (no longer available) caps and the difference was remarkable. I posted more information on this in this forum way back when I did this. I recommend you buy the Dayton caps if thats what you want to use and recap only one of your AR-11s. Then do your own listening tests comparing the Dayton recapped AR-11 against the originally capped AR-11. If you like what you hear, stick with the Dayton caps. If not, you can return any unused Daytons to Parts Express and try something else. Maybe some of their Solens. The Daytons are relatively small and you might be able to mount them where the original caps are. Solens and others are much bigger and you may have to rearrange things on the crossover board to fit them in.
  12. Besides the mid-bass being replacements on your AR-9s, it looks like the tweeter(s) are also replacements. I'm not sure if they are even AR tweeters from another, later series. The mid-bass driver may be an AR 8 inch driver made by Tonegen for a later series of AR speakers such as the AR-9LS /LSi. When I bought my pair of AR-9s they had the Tonegen 8 inch mid-bass drivers that the previous owner had received from AR to replace his original drivers when the foam had rotted. Keep trying e-Bay for original drivers. I was able to secure a pair of original 8 inchers for my AR-9s a few years ago. Just had to refoam them and had an a pair of all original AR-9s again. Rich
  13. It's been too many years since I compared AR-3a's and AR-LST's to each other (mid 70's). However, in the past few years I made direct comparison listening tests between the AR-LST, the AR-11 (similar to the AR-3a), and the AR-90. >>Do LST's sound inherently different from 3As? That may seem a dumb question but they share the same drivers so I was wondering if there is a difference in the basic sound quality or is it primarily that the LSTs throw a better soundstage due the angled cabinets and, of course, can handle more power.<< The LST does sound "different" from other AR speakers. The sound stage is different as you state. However, you can get the LST to have a very similar "voice" to the AR-3a by manipulating the spectral balance switch. Of course the AR-9 / AR-90 sound different from the AR-3a / AR-11 also. If you ever get your hands on a pair of LST's or can listen to them you will not be disappointed. One thing about my experience with the LSTs -- they require significantly more power to get them to really "sing" and bring out their true greatness compared to even the AR-9. Rich
  14. Aleksandar, If you are only removing the capacitors and replacing them with capacitors of similar size I recommend you carefully desolder the leads from what they are connected to and then pry out just the capacitors with a short screwdriver, putty knife, or mini pry bar -- about 4 inches long. I've removed many crossover components from AR speakers and usually the hot glue will break free from the board without taking too much of the board with it. You may (probably will) have to carefully remove the resistor board using the same tools to get at some of the capacitor leads. If you are going to use bigger (polypropylene) capacitors to replace the electrolytic caps, you may have to reposition other components on the crossover boards to get everything to fit. When I recapped a pair of AR-90s I found it easier to remove all the components from the both boards without removing the boards. I build new boards on masonite pegboard and glued these new board to the old boards inside the cabinet. The key on the vertical board is to line up holes you make for the binding posts with the binding post holes in the original crossover board that you left in the cabinet. Hope this helps Rich
  15. Nice cabinets. As I suspected, you have the single board crossovers. BTW, your resistors show no signs of scorching, so I would just leave them alone. Out of curiosity, are your midranges original or were they ever replaced? The reason I'm asking is to get an idea of when AR changed the midrange from the AR-3a midrange (black screen) to the newer midrange (silver screen). Your tweeters are definitely a later version of the "AR-11A" tweeter. They have the older AR "font", but have black cloth dome instead of earlier white/yellow cloth dome. AR-11B tweeters have diffraction foam on the face plate. RE: Dayton capacitors -- I tried these in an AR-90 restoration. I built up one crossover with the Daytons and compared it to an original AR-90 (with old/ and later measured out of spec capacitors). The Daytons sounded as bad as or worse than the original (bad) capacitors. I sent the unused Dayton caps back to Parts Express and bought Solens. I DO NOT recommend Dayton caps. IMHO, spend the marginally extra money on Solens. If you stay with the Daytons or change to Solens, I recommend you apply a little solder to your twisted wire connections. Rich
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