Giorgio AR Posted March 19, 2021 Report Share Posted March 19, 2021 Just buy this pair of early AR3a, n ° H3a 3603 and 4342. My great surprise after removing the glued grilles, in the one with n ° 3603 (this probably has undergone maintenance over the years) I found the woofer with cloth surround. The other speaker was untouched and has the woofer with foam surround, clearly to replace the foam! This pair is the octave I own with 12 "woofers and I'm happy with it, I finally now own a 12" woofer with Alnico magnet! The surprise immediately after removing the grilles The speakers after removing the grilles fixing glue and starting cleaning AR3a's with grilles Rear labels Quote Link to comment Share on other sites More sharing options...
giovanni56 Posted March 23, 2021 Report Share Posted March 23, 2021 In 1969 it happened to buy a pair of Ar3a with Alnico woofers, both with smooth and corrugated cone; it was difficult to notice the difference on the woofers, because the frames were glued and removing them would void the warranty. The engineer Gianfranco Maria Binari (later editor of SUONO STEREO HI-FI), in 1969, bought a pair of Ar3a, with a woofer in corrugated cone and the other smooth; he noticed it, because with a flashlight he illuminated the woofers through the front cloth; later he was able to get a pair with both smooth woofers from the seller. Quote Link to comment Share on other sites More sharing options...
giovanni56 Posted March 23, 2021 Report Share Posted March 23, 2021 On 19/3/2021 at 20:50, Giorgio AR said: Basta acquistare questa coppia di primi AR3a, n ° H3a 3603 e 4342. La mia grande sorpresa dopo aver rimosso le griglie incollate, in quella con n ° 3603 (questa probabilmente ha subito manutenzione negli anni) ho trovato il woofer con rivestimento in tessuto. L'altro altoparlante non è stato toccato e ha il woofer con rivestimento in schiuma, chiaramente per sostituire la schiuma! Questa coppia è l'ottava che possiedo con woofer da 12 "e ne sono felice, finalmente ora possiedo un woofer da 12" con magnete in Alnico! La sorpresa subito dopo aver rimosso le griglie Gli altoparlanti dopo aver rimosso le griglie fissano la colla e iniziano la pulizia AR3a è con griglie Etichette posteriori Have you checked to see if the filters in the two cases have identical component values Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted March 23, 2021 Author Report Share Posted March 23, 2021 3 hours ago, giovanni56 said: Have you checked to see if the filters in the two cases have identical component values Dear Giovanni, thank for your greath informations and the unseed article atached in photo (great article!). I knew that in the first examples of AR3a's the woofer has undergone various evolutions up to then reach the final form and finally land in the following AR10/11 and derivates. As soon as I can insert photos of the variations from the originals woofer. As you know I'slow in my works but the complete revision of this pair of AR3a's is already planned,crossover also! It Will all be documented with photos and published over time on site for the benefit of all! Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted May 13, 2021 Author Report Share Posted May 13, 2021 Work progress: Removed the old capacitors, completely out of specification (all in wax and paper with a total weight of 2.53 kg. !!, the weight of the new substitutes is now 580 gr., almost 2 kg less than the old and obsolete capacitors!), ready the new capacitors, paper and oil for mid. and tw, you see them in the photo below. Purchased 4 new pots from JKent, new foam for the woofer with ceramic magnet, now I begin to restore my pair of AR3a ... Quote Link to comment Share on other sites More sharing options...
DonT Posted May 13, 2021 Report Share Posted May 13, 2021 Very nice looking pair. I will be watching with interest. Quote Link to comment Share on other sites More sharing options...
ar_pro Posted May 15, 2021 Report Share Posted May 15, 2021 Please let us know what you think of the new paper & oil capacitors. Quote Link to comment Share on other sites More sharing options...
DonT Posted May 17, 2021 Report Share Posted May 17, 2021 On 3/23/2021 at 10:44 AM, giovanni56 said: In 1969 it happened to buy a pair of Ar3a with Alnico woofers, both with smooth and corrugated cone; it was difficult to notice the difference on the woofers, because the frames were glued and removing them would void the warranty. The engineer Gianfranco Maria Binari (later editor of SUONO STEREO HI-FI), in 1969, bought a pair of Ar3a, with a woofer in corrugated cone and the other smooth; he noticed it, because with a flashlight he illuminated the woofers through the front cloth; later he was able to get a pair with both smooth woofers from the seller. Okay is it possible that these where original also? One smooth with foam surround and one ribbed. With the real early serial numbers on mine I am thinking no. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted May 23, 2021 Author Report Share Posted May 23, 2021 Splendid, like my couple a woofer in Alnico and one with a ceramic magnet, in your case the woofer could be from what you see around 1974, so late in production ( note the short tinsel of these woofers), I am attaching photos of my 23-74(AR3a improved equipment) woofer but with foam correct as its installation. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted July 14, 2021 Author Report Share Posted July 14, 2021 Small update ... After many doubts: do I leave the pair like this, an Alnico woofer and other ceramic or do I exactly pair these early AR3a with the pair of Alnico woofers? I finally bought the original cufflink, dated 1969 in good condition. This woofer also restores the relationship with the crossover coil as it originally was. New woofer My AR3a woofer Other my AR3a woofer Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted July 15, 2021 Author Report Share Posted July 15, 2021 I update by showing the old wax capacitors and their weight in grams, the fixing brackets above the double capacitor... ... And the new capacitors, the weight of these and in the last two photos the values measured at the 150uF capacitors Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted July 25, 2021 Author Report Share Posted July 25, 2021 Here we have the values measured on the original capacitors removed ... Luckily, there are discrepancies of over 200% on the original declared value !! Measured value-------Project value---------------Value substitutes Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted July 25, 2021 Author Report Share Posted July 25, 2021 And under another pair of AR3a by an acquaintance of mine, probably year '71, assembled in the Dutch factory about 5xxx serial number (European numbering not USA). And under another pair of AR3a by an acquaintance of mine, later than my pair, probably year '71, assembled in the Dutch factory about 5xxx serial number (European non-US numbering), the next photo is the contemporary AR with US cabinet ( note the front baffle, in lamellar pine), slightly different for construction than the Europe one. The woofers, mid's and tweeter are identical in both cases. European, perfect pair... ...USA original style To finish the AR3a evolution, here is the latest European version, AR3a improved (these were my 7/74) with the correct original components. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted July 26, 2021 Author Report Share Posted July 26, 2021 The woofer arrived a little while ago, "almost" well packed, all the canvas roll of the suspension had collapsed ... after loving care and a few hours, here is finally the missing twin woofer. On right new woofer My original woofer dated Oct 28 1969 New wooder, dated Mar 31 1969? Quote Link to comment Share on other sites More sharing options...
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