Guest groved Posted June 19, 2006 Report Share Posted June 19, 2006 Minh- How right you are!Accessing, removing, disassembling, cleaning, lubricating and reinstalling the old pots, only to find that after a few months the "death spots" start appearing again, is a real pain. But, experience says, if one must replace the original 15ohm pots with 8ohm L-pads, the AR dome tweeters MUST be protected from damage due to the lowered crossover point. The blocking cap is all that stands betwen full power and the already hard-to-find, fragile AR tweeter!I have made this change in the past for AR-2ax and AR-5 tweeters by replacing the existing 4uF blocking cap with a 2.6uf cap (I wouldn't go any higher than 3uF), while the existing 6uF cap in the AR-3a should be replaced by a 4uF cap (Roy mentioned this 3a crossover change in his 12/04 post). I suppose one alternative to these cap changes would be to install a 15 or 20ohm non-inductive power resistor across the tweeter leads to simulate the original pot. Any further mods would change the crossover slope even more.When replacing pots with L-pads, I have not messed with the 2ax, 5 or 3a midrange crossover circuits, but be aware that there will be more lower midrange "presence" (i.e. lowered crossover) if one does not adjust the midrange cap values accordingly (drop from 50uF to around 40uF for the AR-3a).These measures will help to retain the original design (and speaker "voice"), and preserve the tweeters at least.To those who decide to replace the pots with L-pads, exercise caution, and best of luck!From a life-long AR enthusiast and hobbyist!Cheers, Doug Link to comment Share on other sites More sharing options...
mluong303 Posted June 19, 2006 Author Report Share Posted June 19, 2006 John O'hanlon and Roy Champagne are the two knowledgeable people who explained the difference between Pots vs L-Pad. I just read and paste Roy's old posts. They deserved the credits, not me.Minh Luong Link to comment Share on other sites More sharing options...
mluong303 Posted August 5, 2006 Author Report Share Posted August 5, 2006 Hello,Does anyone in the AR Forum own the Heathkit AS-103A or AS-103 speaker assemble manual? It is a small booklet and the speakers are the Heathkit version of the Acoustic Research AR-3a. I will pay for a decent photocopy if it is available. I am in the process of restoring a pair and would like to know more about these AS-103A speakers. Thanks in advance for any help or lead.Minh Luongmluong303@aol.com Link to comment Share on other sites More sharing options...
mluong303 Posted August 24, 2006 Author Report Share Posted August 24, 2006 There is a big picture and write up about Mr. Edgar Villchur being #1 as the most influential audio pioneer of all time in the current issue of UK HiFi News. Anyone who is interested should purchase the Magazine to check it out.Minh Luonghttp://www.classicspeakerpages.net/dc/user_files/1523.jpg Link to comment Share on other sites More sharing options...
mluong303 Posted September 17, 2006 Author Report Share Posted September 17, 2006 Hi, EveryoneYou can order any reproduced vintage HiFi owner manual from Vintage Manuals, Inc. They offer the most complete list compare to any other people on the internet and their manuals are professionally duplicated.http://www.w7fg.com/manual.txtMinh Luong Link to comment Share on other sites More sharing options...
Carlspeak Posted September 17, 2006 Report Share Posted September 17, 2006 Wow, 7256 views and 104 replies on this original post!Mark, is that a record?Remember, it's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
mluong303 Posted September 30, 2006 Author Report Share Posted September 30, 2006 The AR Limited stereo system project was conducted by David Day Sequerra. The goal of the AR Limited 3 speaker system was to ¡°Combine the power of dynamic drivers with the delicacy associated with electrostatics". The speaker system alone priced for $7000 a set in 1994. Although they are the most expensive and best sounding AR speakers ever manufactured, they are the least known AR speaker model due to the high price tag and very few were ever built. Also at that time AR tried to market the AR Limited 3 speakers complete with the entire AR Limited electronics and EQ as a set system like Cello marketing their gears to their customers.The Limited 3 speaker system is a 3 way four-driver speaker system that includes an open MTM (midrange ¨C tweeter - midrange) design on top of the acoustic suspension woofer module. The tweeters are custom ordered square flange Dynaudio D260 1" soft dome tweeters. The midrange drivers are Dynaudio D76 3" soft domes. The MTM array is mounted on an open baffle to ensure freedom from dispersion anomalies. The 12" MkII woofer is heavy duty cast frame, fabric laminated poly cone with rubber surround and focus field magnet structure.Each speaker consists of 2 modules. The top module houses the MTM array and the Mids / Hi crossover board is mounted on the back of the base board with metal case protecting the crossover components. The bottom module contains the woofer and the huge woofer crossover board backing with heavy-duty gold plated bi-wired terminals. The bass module is extremely well built and heavily braced internally. The crossovers feature 12 AWG air-cored coils and expensive mixed of polypropylene capacitors of different brands. The optional grill constructed with black metal screen with piano lacquered side panels (another option is solid Cherry side panels as shown in picture).AR Limited 3 speaker system spec:System Type: Dynamic 3-way acoustic suspensionDrivers: 12¡±laminated polypropylene woofer, two 3¡±soft dome midranges, 1¡±soft dome tweeterImpedance: 4 ohmsPower handling: 200 watts continuous, 800 watts peakCrossover: 300 Hz and 2500 HzSensitivity is 88 dB for 2.83v @ 1 meterDimensions: 52¡± x 16¡± x 14¡± with grillsWeight: Approx 200 lbs. boxedeBay item number: 110037483890Good Luck,Minh Luonghttp://www.classicspeakerpages.net/dc/user_files/1619.jpg Link to comment Share on other sites More sharing options...
Guest Eunomians Posted September 30, 2006 Report Share Posted September 30, 2006 Fascinating stuff. I am glad to finally see a pic of these elusive beasts. Cheers Link to comment Share on other sites More sharing options...
mluong303 Posted October 29, 2006 Author Report Share Posted October 29, 2006 The original Mark Levinson's Cello Amati, Stradivari, Master and Grand Master speakers were all employed with special ordered AR drivers for the first 8 years. The Dynaudio drivers adoption came in around the time when the AR Limited 3 speaker system was marketed in 1994 and after then the Cello Legend speakers came along and so did the new series of Cello Stradivari speakers and the Amati Pro which all used Dynaudio drivers until the end.Minh Luonghttp://www.classicspeakerpages.net/dc/user_files/1691.jpghttp://www.classicspeakerpages.net/dc/user_files/1692.jpghttp://www.classicspeakerpages.net/dc/user_files/1693.jpg Link to comment Share on other sites More sharing options...
mluong303 Posted October 31, 2006 Author Report Share Posted October 31, 2006 The original Mark Levinson speaker system in early ¡¯70 with stacked QUAD ESL57 electrostatic speakers with Decca ribbon tweeter in between.In the early ¡¯90, AR actually decided to switch to Dynaudio drivers for the hi-end AR Limited 3 speaker system before Cello decided to do theirs.Following are pictures of Mark's later Cello Amati Pro, Legend and Stradivari Master speakers with Dynaudio drivers designed by Paul Jayson. This is the original Mark Levinson¡¯s Cello website:http://www.marklev.com/cello/index.htmlMinh Luonghttp://www.classicspeakerpages.net/dc/user_files/1706.jpghttp://www.classicspeakerpages.net/dc/user_files/1709.jpghttp://www.classicspeakerpages.net/dc/user_files/1710.jpghttp://www.classicspeakerpages.net/dc/user_files/1711.jpg Link to comment Share on other sites More sharing options...
mluong303 Posted November 11, 2006 Author Report Share Posted November 11, 2006 The AR-3a / AR-11 1.5" coated soft dome midrange was a very well built with huge 30-oz magnet that is capable of reaching the very low crossover point of 575 Hz in the AR-3a / AR-LST and 525 Hz in the AR-10Pi / AR-11 crossover designs. It was rated at 89 db with maximum power handling of 100W RMS. This was the only AR dome midrange that would reach this limit without any problem. The AR-303 / 303A midrange with smaller 20-oz magnet was designate for the crossover point of 650 Hz in the AR-303 and AR-303A which may not be able to get this low in the frequency range. The accurate sounding characteristic with high power handling and wide dynamic range made this 1.5" soft dome midrange to be the most unique AR driver of all...Minh Luonghttp://www.classicspeakerpages.net/dc/user_files/1745.jpg Link to comment Share on other sites More sharing options...
mluong303 Posted November 24, 2006 Author Report Share Posted November 24, 2006 Restoration process of a pair of AR-3a speakers in Japanhttp://www.onomichi.ne.jp/~ishii/ar3a/index.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index2.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index3.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index4.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index5.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index6.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index7.htmlhttp://www.onomichi.ne.jp/~ishii/ar3a/index8.htmlMinh Luong Link to comment Share on other sites More sharing options...
mluong303 Posted November 27, 2006 Author Report Share Posted November 27, 2006 This is another line of AR speaker models worth looking into but not too many people know or care about! They were designed for Home Theater with big screen set up. Hopefully, someone in the CSP Forum has the sale brochure to scan in and show the Woofer cut away and explanation of the technology behind the new woofers in these streamlined cabinets design.Acoustic Research 8.3 Phantom SpeakersPrinciple 3-way speaker with Placement Compensation NetworkFrequency response 45 - 20.000 HzRecommended Amplifier Output 50 - 250 WattsSPL (1w/1m) 89 dBDimensions (WxHxD) without stand 11,7“ x 28,5“ x 3,7“Cabinet Surface streamlined cabinet in versatile satin-finish aluminium with neoprene dampingFeatures Low profile enclosure 1“ plasma-hardened titanium dome tweeter MagAlloy™ 2“ dome midrange Illusion™ 8“ long-throw Carbon Series woofer Dual binding posts for bi-wire/bi-ampeBay Item number: 230054573682Minh Luonghttp://www.classicspeakerpages.net/dc/user_files/1771.jpg Link to comment Share on other sites More sharing options...
mluong303 Posted May 20, 2007 Author Report Share Posted May 20, 2007 U Tube clips on Woofer building and Audiophiles speaking of their Love.http://www.youtube.com/watch?v=daNVRHzdIsE Minh Luong Link to comment Share on other sites More sharing options...
mluong303 Posted January 2, 2008 Author Report Share Posted January 2, 2008 The extension of AR speaker philosophy into the next Century! By the way, Honda was the Automobile Company chose AR speakers for their Sound System in the '80.Minh Luong Link to comment Share on other sites More sharing options...
mluong303 Posted January 16, 2008 Author Report Share Posted January 16, 2008 I am still dreaming about the 50th AR Birthday Party...!!! Link to comment Share on other sites More sharing options...
mluong303 Posted January 30, 2008 Author Report Share Posted January 30, 2008 I just locate this old letter from Ken in 1994 regarding the AR-3a Limited.FROM THE DESK OF KEN KANTOR11/14/94Minh - Thanks for the photos and feedback!I've passed both along to our marketing and sales people for consideration.A few points:1- The "new" 303 will be available in a wood finish closer to the classic look, as will all the new products. These are shipping this month, but weren't ready for the NY event. Not exact, but closer.2- The 3a has been resurrected about 4 times. Most recently a run of 500 pr with gold terminals, bi-wiring, etc. This did well in Asia, but nobody wanted to carry them in the States. It is our view that, aside from a few dozen AR loyalists, who can find the new 3a's around anyway. The 3a hunger has been pretty much filled. So we are concentrating on a newer look to go with the newer technology.3- SR (Stereo Review), Audio and, possibly, Audiophile are doing 3a/303 comparison articles. I'm looking forward having done this for 100 hrs myself.Stay in Touch!Ken. Link to comment Share on other sites More sharing options...
genek Posted January 30, 2008 Report Share Posted January 30, 2008 The 3a has been resurrected about 4 times. Most recently a run of 500 pr with gold terminals, bi-wiring, etc. This did well in Asia, but nobody wanted to carry them in the States. It is our view that, aside from a few dozen AR loyalists, who can find the new 3a's around anyway. The 3a hunger has been pretty much filled. So we are concentrating on a newer look to go with the newer technology.Darn, now I knowI missed my last chance for sure. Link to comment Share on other sites More sharing options...
mluong303 Posted February 8, 2008 Author Report Share Posted February 8, 2008 If I get a decent offer, I will let go my AR-3a Limited, AR-3a Improved, AR-3a and Cello Amati speakers... Minh Luongmluong303@aol.com Link to comment Share on other sites More sharing options...
mluong303 Posted November 21, 2008 Author Report Share Posted November 21, 2008 I just locate this old letter from Ken in 1994 regarding the AR-3a Limited.FROM THE DESK OF KEN KANTOR11/14/94Minh - Thanks for the photos and feedback!I've passed both along to our marketing and sales people for consideration.A few points:1- The "new" 303 will be available in a wood finish closer to the classic look, as will all the new products. These are shipping this month, but weren't ready for the NY event. Not exact, but closer.2- The 3a has been resurrected about 4 times. Most recently a run of 500 pr with gold terminals, bi-wiring, etc. This did well in Asia, but nobody wanted to carry them in the States. It is our view that, aside from a few dozen AR loyalists, who can find the new 3a's around anyway. The 3a hunger has been pretty much filled. So we are concentrating on a newer look to go with the newer technology.3- SR (Stereo Review), Audio and, possibly, Audiophile are doing 3a/303 comparison articles. I'm looking forward having done this for 100 hrs myself.Stay in Touch!Ken.Based on Ken's note and the serial numbers I got from an Korean owner. There should be 800+ pairs of AR-3a Limited exist around the World...Minh Luong Link to comment Share on other sites More sharing options...
Carlspeak Posted November 21, 2008 Report Share Posted November 21, 2008 Mluong, it looks from your pictures of the limited versions of the 3a without grilles that AR started to make a decent looking baffle board. Perhaps they began to understand some folks liked to listen to them without the grilles? Earlier vintages are pretty ugly without grilles. Link to comment Share on other sites More sharing options...
mluong303 Posted November 21, 2008 Author Report Share Posted November 21, 2008 Three of my favorite AR speaker models I used to own which have excellent wood veneer covered were the AR-10Pi, AR-9LSi and AR-303A. But if I have the money to contract a custom shop to build me a pair of AR-3a speakers now, it will look like this.Minh Luong Link to comment Share on other sites More sharing options...
onplane Posted November 21, 2008 Report Share Posted November 21, 2008 Mluong, it looks from your pictures of the limited versions of the 3a without grilles that AR started to make a decent looking baffle board. Perhaps they began to understand some folks liked to listen to them without the grilles? Earlier vintages are pretty ugly without grilles.Carl, are you saying the terminals and the black electrical tape are "ugly"?Well, they aren't pretty, that's for sure. Nevertheless, they do allow easy analysis as in my recent post in the tweaks and mods. That is, being able to monitor the xovers without having to open the boxes sure is a nice feature.Regards,Jerry Link to comment Share on other sites More sharing options...
Carlspeak Posted November 22, 2008 Report Share Posted November 22, 2008 Jerry, I was saying the early baffle boards were (still are) ugly. Those early dome designs weren't capable of back wiring, so they had to do what they did. But the board itself wasnt finished well at all. I can only presume they weren't intending to have the speakers listened to with the grilles off. It just wasn't done normally at the time IMO. Maybe TT can elaborate on this.[nice plug for you mod here though]. Link to comment Share on other sites More sharing options...
mluong303 Posted January 1, 2011 Author Report Share Posted January 1, 2011 Happy New Year and Best Wishes for 2011.Minh and Family Link to comment Share on other sites More sharing options...
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