Andre_Db66 Posted January 31 Report Share Posted January 31 https://www.marktplaats.nl/v/audio-tv-en-foto/luidsprekers/m2075381533-te-koop-iconische-ar-3a-speakers-in-near-mint-condition I came across these on dutch craigslist. It seems to me there is something not correct. My findings are the woofers are not original. The tweeters dont seem to be either. No pot on the back so who knows what has been done inside. I even doubt the correctness of the mid drivers. Maybe i am way off in my assumption. Any ideas? Quote Link to comment Share on other sites More sharing options...
Gaston Posted January 31 Report Share Posted January 31 Woofers are original, they need to be refoamed. Tweeters are probably from next gen AR-11/10π. Mids looks like Tonegen replacement drivers. AFAIK everything is ok-ish with drivers unless you want an all original pair. The unknown lies inside, since there are no pots, there is a big concern that the crossover has been modified. Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted January 31 Author Report Share Posted January 31 Ah... i thought the woofer to be tonegem. As it resembles one golden cage edition i have in a set of improved badge labeled 3a's. The asking price was 400, and bidding was at 375 about an hour ago. Quote Link to comment Share on other sites More sharing options...
Gaston Posted January 31 Report Share Posted January 31 Maybe you are right, the pictures provided are pretty bad, so definitive conclusion from someone with better eye. However, who knows what's happening inside (the crossover). edit: this thread maybe can help you (it seems they are really Tonegen, not original as I assumed): Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 1 Report Share Posted February 1 It appears to me that all of the drivers are Tonegen. This would be consistent with the AR-3a Limited of the early 90's, sold primarily in Europe and Asia. It is unusual, however, to not see level controls. I agree with Gaston, the crossovers should prove interesting. Imo, the drivers alone are worth 400. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 1 Author Report Share Posted February 1 8 hours ago, Gaston said: Maybe you are right, the pictures provided are pretty bad, so definitive conclusion from someone with better eye. However, who knows what's happening inside (the crossover). edit: this thread maybe can help you (it seems they are really Tonegen, not original as I assumed): You are right Gaston, this is what i based my deduction on together with the drivers in my own speakers. The silver edition i have in my LST, the gold in a set of 3a impr labeled speakers, with the wires cut from the front and everything connected from the back... the edge and dustcap give it away in my view. I only wondered about the cabinet and serial #, i have uk impr cabinets from 76, they are different style. How would that be consistent with limited version sold more than 14 years later in a usa cabinet with low sn? (I read (blurry)Cambridge at the bottom) I have offered the guy i would like to take them. At least i can refoam (perhaps recap) and sell again or sell another set. Thanks guys Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 1 Report Share Posted February 1 The crossover of the 3a "Improved" departed from the original design more than any other version of the 3a. It had the same cabinet design as the original European AR-3a, and was a relatively short-lived transition model just prior to the introduction of the AR-11 in the mid 1970's. The 3a "Limited" of the early 90's went back to the original US cabinet style. It had an adjustment to the original crossover configuration to accommodate modern 8 ohm L-pad level controls and the AR-11 style (Tonegen) cloth dome tweeter...along with woofer-to-high/mid range jumpers. Most of these have been found to have vinyl clad cabinets, though some have been reported to have walnut veneered cabinets as well. I recall variations in Italy described in this forum some years ago. Although apparently marketed primarily in Asia and Europe, I have seen US-manufactured 3a Limited cabinets. The 3a Limited was an excellent sounding version of the 3a. The Tonegen drivers were of high quality, very consistent, and have held up well. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 1 Author Report Share Posted February 1 I have a gentlemens agreement with the seller. I am to pick them up sunday and as the woofers have to be refoamed i will open them up. Lets see what the inside reveals.... What i also noticed btw was the residue of putty around the woofer, which so far i have only had on my alnico ar6 speakers... Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 3 Report Share Posted February 3 On 2/1/2024 at 5:15 PM, Andre_Db66 said: .What i also noticed btw was the residue of putty around the woofer, which so far i have only had on my alnico ar6 speakers... It is not likely for putty to have been originally used with this generation of AR speaker. Given the absence of level controls someone has obviously modified this pair, so any putty you find will not be original. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 4 Author Report Share Posted February 4 A quick look inside reveals the gold basket tonegem woofer. Ar3a xo with 1 deviation. Instead of 150uF 133uF has been applied. They are in fact ar3a speakers, the serial numbers are correct and the official import handler of Holland at the time provided all the upgrade drivers. So without looking i think it is correct to assume the drivers are all Tonegem. The bi-amp schematics found elsewhere in the forum has been used here. The bridge outside really divides the xo in 2 parts and it is safe to connect any 2 amps with the bridges removed. Cherry on the cake is that i have obtained the original 4 pots with the sale. As the pots are out the speakers simply blast out full on the mid/tweeters unattenuated. A bid had been made of 600 but as i was very early in negotiating i was lucky to take this find home for 400 including the pots. Someone say that the drivers alone were worth 400? 😁 Anyway, i am going to put in the Tonegem woofer with rubber surrounds and listen. I will revert the biamping with the two original pots later . Placing them on my original stands which i received yesterday by mail for 125. They will never depart my home again. The Frankensteins i am not yet certain about, but apart from the badge i do know now they come very close to each other in terms of drivers and xo. I am only wondering if i should add the remainder caps to obtain the value of 150uF or is the advice with these to woofers to leave as is...? The other are hooked up to new 150uF btw. If the latter then it means the 150uF of the Frankenstein should be altered too in case i decise to stack them at one point. Cheers Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 4 Author Report Share Posted February 4 Discovered an addition in the xo which i hadnt noticed. There are 20 resistors placed parallel to the tweeter and also to the mid. Due to glue i am having trouble lifting the tweeter but the mid is a gold magnet version very much same as the woofer, so indeed Tonegem. Effectively if i am right about the color code it is the equivalent of 12.5R. How much does that attenuate? Or is there none? The mid and high seem full throttle. Yet a/b comparison with LST in position 3 is very little difference. Perhaps a little more sharp edged... Quote Link to comment Share on other sites More sharing options...
jackswagger Posted February 5 Report Share Posted February 5 On 2/4/2024 at 10:44 PM, Andre_Db66 said: A quick look inside reveals the gold basket tonegem woofer. Ar3a xo with 1 deviation. Instead of 150uF 133uF has been applied. They are in fact ar3a speakers, the serial numbers are correct and the official import handler of Holland at the time provided all the upgrade drivers. So without looking i think it is correct to assume the drivers are all Tonegem. The bi-amp schematics found elsewhere in the forum has been used here. The bridge outside really divides the xo in 2 parts and it is safe to connect any 2 amps with the bridges removed. Cherry on the cake is that i have obtained the original 4 pots with the sale. As the pots are out the speakers simply blast out full on the mid/tweeters unattenuated. A bid had been made of 600 but as i was very early in negotiating i was lucky to take this find home for 400 including the pots. Someone say that the drivers alone were worth 400? 😁 Anyway, i am going to put in the Tonegem woofer with rubber surrounds and listen. I will revert the biamping with the two original pots later . Placing them on my original stands which i received yesterday by mail for 125. They will never depart my home again. The Frankensteins i am not yet certain about, but apart from the badge i do know now they come very close to each other in terms of drivers and xo. I am only wondering if i should add the remainder caps to obtain the value of 150uF or is the advice with these to woofers to leave as is...? The other are hooked up to new 150uF btw. If the latter then it means the 150uF of the Frankenstein should be altered too in case i decise to stack them at one point. Cheers Hello, It sounds like you've made quite a find with these AR3a speakers and have been working on some interesting modifications. It's great that you were able to obtain the original pots and are experimenting with different configurations. Regarding the deviation in capacitor value (133uF instead of 150uF), it seems like a minor difference. If the speakers sound good to your ears and you enjoy the current performance, you might not necessarily need to add the remainder caps to achieve the nominal 150uF. The sound characteristics can be quite subjective, and if the speakers deliver the desired audio quality, leaving them as is might be a good option. However, if you're inclined to explore further, you could experiment with different capacitor values to see if there are any noticeable differences in sound. It's often a trial-and-error process, and personal preferences play a significant role. As for the bi-amping and reverting to the original pots, it sounds like you have a plan for testing various configurations. Trust your ears and preferences in this process. The Frankensteins and the original AR3a speakers seem to have interesting similarities, and it's always fascinating to discover and compare the components. If you're happy with the current sound, leaving the capacitors as they are might be a reasonable choice. If you're curious and want to experiment, you can try adjusting the capacitor values to see if there's any sonic improvement that aligns with your preferences. Enjoy your audio journey, and cheers! Name Combiner For Two Names Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 5 Author Report Share Posted February 5 Thank you for your elaborate answer. I am just curious what the 20 * 300R parallel with the tweeter is for. (Similar addition for the mid speaker) I have not seen any AR so far with this nor any schematic. As for the sound, i find them very open and a bit harsh sounding. Like the pots are fully open. I tend to prefer the middle setting with most speakers ie LST. 3A Impr has a similar voicing signature as this ar3a and i cannot alter but a/b switch them, but not necessarily the AR6. Those are more balanced when the pot is opened up. Ar6 Sounds a bit muffled with the pot in the middle. The Frankenstein have the tweeter pot opened up but mid toned down and sound very closed in dirext comparison to my newly acquired 3a. So putting back the pots i will certainly do as i do not care for biwire and especially not for biamping. Bin there done that... Today i tried a Yamaha PC2602 on the 3a and pretty loud and they seem to push the ar3 effortlessly not breaking a sweat. No clipping. The Yamaha M2 i pushed into clipping to my surprise the other day. PC2602 is 2 * 400@4R btw. If it becomes too much it has a fan as backup. Actually next test will be the 2602 on the LST as that speaker is even harder to drive. Not sure yet which eventually will be used for the ar3a. Plenty of choice so takes time to match them perfectly, amp and speakers. Cheers Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 5 Author Report Share Posted February 5 Woofer swap with rubber surround Tonegem and made the tweeter black again. Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 6 Report Share Posted February 6 8 hours ago, Andre_Db66 said: I am just curious what the 20 * 300R parallel with the tweeter is for. (Similar addition for the mid speaker) I have not seen any AR so far with this nor any schematic. No iteration of the 3a used this resistor arrangement. Obviously, whoever rebuilt the crossover substituted the pots with this. I'm not sure I understand your description, but if it is as you suggested, 12.5 ohms in parallel with the tweeter and mid, it would be similar to the pots being set near maximum. When the pots were set to maximum they provided 15 ohms in parallel, and no series resistance. The primary reason for the harshness is that the Tonegen/AR-11 type of tweeter absolutely requires a crossover change to keep it from producing too much output in the mid frequencies. A .16mh coil and 4uf cap were used in the 3a Limited (along with 8 ohm L-pads.) The bundled 133uf woofer caps shown in your photo don't have a strong voltage rating for the woofer circuit. I would replace them, and simply go back to the original value of 150uf. The 3a Limited retained the original 150uf cap value and a slightly smaller 2.6mh coil with the Tonegen woofer. The 3a Limited's Tonegen midrange crossover was also slightly different from the original 3a, having a .7mh parallel coil instead of the original .88mh coil. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 6 Author Report Share Posted February 6 Roy, you are right, 35v is much too low as the Quad 303 almost already exceeds this. I shall buy this immediately. Let alone 260 watt yamaha 😁 About the resistors, there are 20 pieces in parallel with tweter and 20 with mid so yes that would make a 12,5R for each unit. Thank you for the effect explanation. As the limited drivers are used, i am aware there was an xo change to accomodate the Lpads, but can i simply place the pots? I happened to have some 1mm ,39 coils which i could unwind to ,16. I gather the cap is necessary, the coil could possibly be avoided with an original pot. The mid could be used as is with the original pot and adjust to taste, right? Unwinding 2,88 is possible or adding 1,0 to a number 7 and unwinding the 1,0 i think is best so to keep AR parts original, no? I presume unwinding will make the woofer louder? By all means, i am no expert and just an audio nutcase enthusiast of 57 years of age so any advice or help is greatly appreciated... Cheers Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 6 Report Share Posted February 6 10 hours ago, Andre_Db66 said: About the resistors, there are 20 pieces in parallel with tweter and 20 with mid so yes that would make a 12,5R for each unit. Thank you for the effect explanation. As the limited drivers are used, i am aware there was an xo change to accomodate the Lpads, but can i simply place the pots? The mid could be used as is with the original pot and adjust to taste, right? Unwinding 2,88 is possible or adding 1,0 to a number 7 and unwinding the 1,0 i think is best so to keep AR parts original, no? I presume unwinding will make the woofer louder? You will still need to use a parallel coil for the tweeters, whether you use L-pads or original pots. It is not just a matter of overall output. It is about taming the tweeter's influence on the mid frequencies (ie. the slope of the crossover). If using original pots stay with the 6uf cap, and add the .16mh coil. If using L-pads, add the coil and reduce the cap to 4uf. The Limited's slightly smaller woofer coil worked in conjunction with the smaller parallel mid coil. To answer your question...a smaller coil in series with the woofer increases its contribution to the mid frequencies. The reason for the coil changes probably had to do with decreasing the load on the midrange at somewhat lower frequencies, and having the woofer compensate for the difference. Staying with the original 3a values will work satisfactorily. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 7 Author Report Share Posted February 7 Thank you Roy... The filter of speaker #1 has been restored. I am making the coils .16 but have a question. Undocumented territory and my knowledge leave me in the dark how to hook uo the .16 coil. Correct would be from inside to out but what is in this case plus and minus. Plus being inside of the coil, is this simply how it is placed in the scheme? So according with schematic... Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 7 Report Share Posted February 7 7 hours ago, Andre_Db66 said: Thank you Roy... Correct would be from inside to out but what is in this case plus and minus. Plus being inside of the coil, is this simply how it is placed in the scheme? So according with schematic... I'm not sure I understand your question. Like the non-polarized capacitors in your crossovers, the coil itself has no polarity to be concerned with. Just connect each lead to the + and - tweeter leads. It doesn't matter which coil wire is connected to which lead. This can be done anywhere between the pot to the tweeter. Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 7 Author Report Share Posted February 7 Within the xo in series i have read that it does matter which way you implement the coil. Being the leadin on the outside of the coil or rather from the center outward. Parallel i can imagine different rule applies. But lacking foundation in education with the matter i have only fora and people like yourself to learn from. I wasnt aware it didnt matter and only popped the q to be sure it isnt installed wrong. I only vaguely remember stuff like cork screw rule... and was thinking with regard to what i read and induction being applied wrong it would render my coil useless... Im pretty much an intuitive kinda guy so pick up things taught along the way. Thank you for all your kind help. The first speaker is now playing with older style tweeter, no coil and basically resembles the frankenstein sonically at the moment. Tonegem mid and woofer in both and same era tweeter and xo. I have ordered an LCR multimeter so i can mesasure the coil for the newer tweeter. Also handy for the caps. Cheers Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 7 Report Share Posted February 7 27 minutes ago, Andre_Db66 said: Within the xo in series i have read that it does matter which way you implement the coil. Being the leadin on the outside of the coil or rather from the center outward. Parallel i can imagine different rule applies. Regardless of location it does not matter any more than it does for capacitor or resistor leads in a passive speaker crossover network. Driver and associated circuit polarity is the only consideration. Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 7 Author Report Share Posted February 7 Ok got it... The wait is for the right tools and parts now... Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 8 Author Report Share Posted February 8 "whenever possible). This method is especially advantageous for AR woofers with cones lower than the basket rim, as it allows you to manipulate the height of the cone during the gluing process." Roy Could you please explain what you mean with this? I have ordered a set with dustcaps and shims. It is the largest refoam job i am attempting so thought it would be a smart move to do it with shims. Until now i used clothes pegs. I am intrigued by your comment. I know from experience that horizontally storage of woofers ruins the spider but until now experienced nothing of that with vertically mountes vintage speakers. Also i wonder why i cannot find rubber surrounds anymore? I have 2 sets mounted on 4 12 inch woofers. One set being in very good shape since 2003 which pretty old by now. The other is of unkown age Cheers Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 9 Report Share Posted February 9 6 hours ago, Andre_Db66 said: "whenever possible). This method is especially advantageous for AR woofers with cones lower than the basket rim, as it allows you to manipulate the height of the cone during the gluing process." Roy Could you please explain what you mean with this? Also i wonder why i cannot find rubber surrounds anymore? The friction of the shims holds the woofer cone at varying heights of your choosing. Along with properly orienting the surround, it makes it easier to install. Most modern replacement rubber surrounds are sold for subwoofer and automotive applications. They are heavier and less compliant than those used for AR woofers. I've never been aware of any rubber replacement surrounds sold for AR speakers. Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 9 Author Report Share Posted February 9 So what would be the height to position the cone? Is there way of determining what the correct height is? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.