giovanni56 Posted June 9, 2022 Report Share Posted June 9, 2022 Hoping to do a good thing Quote Link to comment Share on other sites More sharing options...
Stimpy Posted June 10, 2022 Report Share Posted June 10, 2022 It should be the same as the AR-91, but without the level switches. Great speakers. Quote Link to comment Share on other sites More sharing options...
DavidR Posted June 11, 2022 Report Share Posted June 11, 2022 Hope these help. (3) docs AR58xover.tif Quote Link to comment Share on other sites More sharing options...
lARrybody Posted June 11, 2022 Report Share Posted June 11, 2022 13 hours ago, Stimpy said: It should be the same as the AR-91, but without the level switches. Great speakers. Stimpy is right. Same as the AR91 without the switches. Picture below is AR91 boards recapped with original AR58S board in the middle. This is the difference on the connection side. Quote Link to comment Share on other sites More sharing options...
Stimpy Posted June 11, 2022 Report Share Posted June 11, 2022 11 hours ago, lARrybody said: Stimpy is right. Same as the AR91 without the switches. Picture below is AR91 boards recapped with original AR58S board in the middle. This is the difference on the connection side. Thanks. But, my 58S speakers don't have wires hanging out the back...! Nice job on the recap too. All Jantzen Premium Elko's, or do you have Mundorf E-Caps mixed in too? A shame Jantzen dropped the Elko line. It's getting difficult to find good speaker electrolytic caps. Quote Link to comment Share on other sites More sharing options...
DavidR Posted June 11, 2022 Report Share Posted June 11, 2022 The Jantzen and Mundorf Ecaps are both made by F&T a German company. Quote Link to comment Share on other sites More sharing options...
lARrybody Posted June 13, 2022 Report Share Posted June 13, 2022 On 6/11/2022 at 12:49 PM, DavidR said: The Jantzen and Mundorf Ecaps are both made by F&T a German company. The electrolytes used in the 58S's are mostly Mundorf E-caps. The Jantzen Premium ELKO are basically the same as the Mundorf E-cap AC. It seems the Premium ELKO (smooth) and Mundorf (Plain) versions are slowly disappearing. Jantzen has a new El-Cap non polar with a 5% tolerance. I will be ordering some of those soon. Quote Link to comment Share on other sites More sharing options...
DavidR Posted June 13, 2022 Report Share Posted June 13, 2022 Thanks for the info Larry. I looked up the EI-Cap on the Jantzen website. Where are you buying those? What irritates me is that the 'common sizes' are all changing. e.g. 30uF is now 33uF, 6uF is now 5.6uF, 8uF is now 8.2uF ...................... Quote Link to comment Share on other sites More sharing options...
giovanni56 Posted June 13, 2022 Author Report Share Posted June 13, 2022 I measured the inductances again with precision instrument Quote Link to comment Share on other sites More sharing options...
lARrybody Posted June 16, 2022 Report Share Posted June 16, 2022 Giovanni. I am always amazed how inductors are almost always close to original specs. I guess there is not much to go wrong with a coil of wire. David. Parts Connexion has the El-caps listed. Just yesterday I was re- building a AR-9 upper board and had a 8.2 film cap for the 8 uf value. It tested at 8.4 which put it 5% over. I wound up paralleling two 3 uf and one 2 uf Dayton Precision Caps and wound up exactly at 8 uf I guess that’s what needs to be done to achieve exact values. I know that is not the best approach as far as ESR is concerned. Quote Link to comment Share on other sites More sharing options...
DavidR Posted June 16, 2022 Report Share Posted June 16, 2022 Thanks Larry. I looked as I figured if anyone had them they would. The 80uF and maybe the 40 is still available at Parts Express. The 24 is best made up with a 22 and 2.2. A good thing about Parts Connxtion is if you email the owner (forget his name atm) and ask if they have any that measure high or low he will send you the info. I took a look at ERSE and they still have most of the 'common' values. IIRC the ESRE npe aren't highly thought of. Might be worth avoiding the ESR issue. I don't know about you but I've done ARs with NPE using film bypass caps on the series caps and going the all film cap route and I find the NPE to be better. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted June 18, 2022 Report Share Posted June 18, 2022 On 6/13/2022 at 4:23 PM, giovanni56 said: I measured Giovanni I ask you if by eliminating the 1 ohm and 22 watt resistance on the woofer (already performed by an Italian technical laboratory on the AR78LS with excellent results, also confirmed by instrumental measurements), the low frequency performance, which many have declared lower precisely in AR91 and AR58S, I am attaching the link of the restoration and crossover modifications of the AR78LS. http://www.fletcherandmunson.it/wp-content/uploads/AR_mod_78_LS.pdf I'm sorry for the text in Italian, but the diagrams (with changes) and measurements taken should also be understood by fans of different languages !! Personally, among my pairs of AR speakers I have a pair of AR58S that have been working for years now and I will replace the crossover with that of AR91, a pair of AR91s and a pair of AR98LS, to all these AR speakers I would remove the aforementioned resistance and change the crossover of AR78LS as shown in the PDF. Thanks for your opinion. Giorgio Quote Link to comment Share on other sites More sharing options...
giovanni56 Posted June 19, 2022 Author Report Share Posted June 19, 2022 On 6/18/2022 at 9:34 PM, Giorgio AR said: Giovanni I ask you if by eliminating the 1 ohm and 22 watt resistance on the woofer (already performed by an Italian technical laboratory on the AR78LS with excellent results, also confirmed by instrumental measurements), the low frequency performance, which many have declared lower precisely in AR91 and AR58S, I am attaching the link of the restoration and crossover modifications of the AR78LS. http://www.fletcherandmunson.it/wp-content/uploads/AR_mod_78_LS.pdf I'm sorry for the text in Italian, but the diagrams (with changes) and measurements taken should also be understood by fans of different languages !! Personally, among my pairs of AR speakers I have a pair of AR58S that have been working for years now and I will replace the crossover with that of AR91, a pair of AR91s and a pair of AR98LS, to all these AR speakers I would remove the aforementioned resistance and change the crossover of AR78LS as shown in the PDF. Thanks for your opinion. Giorgio Giorgio, intendi la R da 2 ohm sul C da 100uF del woofer. Quella R ha una funzione "smorzante" e in pratica riduce lievemente la pendenza delle frequenze piu' alte di competenza del woofer ottenendo un incrocio piu' chiuso con il mid; togliendola modifichi acusticamente ed elettricamente l'incrocio woofer/mid diminuendo l'impedenza in un certo range di frequenze Quote Link to comment Share on other sites More sharing options...
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