Tim D Posted December 31, 2017 Author Report Share Posted December 31, 2017 Ok. Done. Here are some pics. They sound great! She's coming tomorrow for her birthday present. I'm getting her a more modern receiver and turntable to get by with until I can get her a proper vintage arrangement to go with the AR-4X's. I've got several Receiver/TT's in the queue that would be nice pairings with them - eventually. I ordered the knobs from PE were mentioned above. I'll see how big they are and maybe retrofit them later at her house if they aren't too big. Quote Link to comment Share on other sites More sharing options...
Tim D Posted December 31, 2017 Author Report Share Posted December 31, 2017 Just some follow-up notes for others.... These are nice speakers - especially for their small size. I wouldn't be disappointed if they were my only speakers - but they are not. These are well worth restoring and the cabinets and veneer are as good or better than most other speakers of that vintage. I was able to clean up most of the stains on the grill cloths and brighten them up using 50-50 mix of plain bleach and water with a spray bottle. Just be mindful that the cloth will shrink. Too much shrinkage and the cloth will start coming apart. I kept the original grill cloths even though they weren't perfect. Just trying to keep them original to the greatest extent possible. I did not have to put on velcro or other attachment. They were a tight fit, so I just pressed them in. No need to take them off again unless there is a future problem. Don't be afraid to replace the old pots with the Lpads from PE. I was hesitant, but I'm glad others were able to convince me to change them out. While I could clean them up and get them partially working, they were still too gritty and had some scratchiness remaining. Just not worth the hassle. Be mindful of the connections on the new Lpads and test to make sure they are wired correctly. Mine initially were working backwards. An easy fix, but if you paying attention it will be less (but minor) re-work than I had. Here is the parts information: Speaker L-Pad Attenuator 15W Mono 3/8" Shaft 8 Ohm Part # 260-248 A big note here. I didn't have the 25 ohm resistors on hand which was part of the Lpad change-out diagram, so I left them out based on others testimonies. They work great without the resistor! They are probably a little brighter, but with the Lpad, that can be adjusted to suit preferences. I had very good luck with the Danish Oil "Natural" finish that was recommended above. I had my concerns, but even the "Natural" darkened up. I definitely didn't need to use the "Dark Walnut". That would have looked too dark on small speakers. I went with two coats. I'll check on them after she's used them for a while and if they look like they need more I'll take care of it for her, but for now two was fine. I was able to make my own putty with sanding dust and wood glue. That is an alternative to buying wood filler for small dings. Use the surround dope from Vintage AR (from RoyC). It works and is safe when used sparingly. I've been using it a while on my KLH speakers and I won't use anything else. I did one light coating as thin as possible so I didn't impact the flexibility of the surrounds. I did not cover the dust caps with dope as these didn't have it on from the factory and no one seemed to indicate that this was needed. This is different from what I learned on the KLH speakers. These sound great and have more bass than I would expect for such a small speaker. Note that they don't pass the push test that I'm used to either, but again they have enough bass for what I'd expect. I chemically stripped the veneer and then sanded first with 200 grit and then later with 320 grit. Always with the grain...... I cleaned up the front baffles and painted them with a convenient black (satin) spray can I had in the garage. They look better, but won't win any beauty contests with the grills off, but I'm not planning for these to be off ever again. I didn't touch the back panel at all except to glue down the labels on the back that were curling up in a couple of places. I was lucky that the original labels were in pretty decent condition. The original badges cleaned up nicely with "Brasso". An easy job. Had I more time I might have put a clear lacquer to keep them from tarnishing. I went with Dayton caps from PE. It's my habit and they work well. Others might want to try a different brand, but I don't think you can go wrong with Daytons. Here is the parts information: Dayton Audio DMPC-20 20uF 250V Polypropylene Capacitor Part # 027-436 Note that I didn't bother to remove the old caps. I just cut the wires and left them bracketed into the speaker. It would have been unnecessary work to remove them IMHO. With the work done on these they'll be good for another 50 years. I expect the Dayton Poly's to last and last in comparison with the typical electrolytics. I don't know about the longevity of the Lpads, but they have to be better than the stock pots. Assuming my daughter doesn't blow the drivers out, I presume she can run these forever with only the occasional maintenance on the veneer and to dust the grills. The best part of it though is that they are vintage, furniture quality, collectable, small enough to not get in the way in any room, and it's very hard to do significantly better acoustically with modern speakers. The kicker was the price I got them at. Even though I had to put in more money for parts and quite a bit of labor, I felt that it was very worthwhile. Thanks to larrybody, ra.ra, RoyC and JKent for their resident expert guidance on this project. They helped guide me down the right paths when I was taking the wrong fork in the road a few times. Quote Link to comment Share on other sites More sharing options...
JKent Posted December 31, 2017 Report Share Posted December 31, 2017 Nice job Tim, and a good guide for others to follow. If I may add a couple of comments: Good call on the Natural as opposed to Dark Walnut Watco oil. Some of us like to use the Mahogany Watco oil to add a bit of warmth to the walnut. It's not a stain and you could apply 1 coat over the natural if you wanted. You were fortunate to have the engraved, not the silk screened brass logos. The engraved ones can be polished, not so much the silk screened. And personally I wouldn't bother with the lacquer--they'll still tarnish UNDER the lacquer and you'll go through that whole process again. Instead, use Gene's grandma's advice and rub just a drop of olive oil on them. You may have to repeat once a year or so. Great work and a wonderful gift. Now what are the receivers and TTs in the queue? Happy New Year! -Kent Quote Link to comment Share on other sites More sharing options...
Tim D Posted December 31, 2017 Author Report Share Posted December 31, 2017 12 minutes ago, JKent said: Nice job Tim, and a good guide for others to follow. If I may add a couple of comments: Good call on the Natural as opposed to Dark Walnut Watco oil. Some of us like to use the Mahogany Watco oil to add a bit of warmth to the walnut. It's not a stain and you could apply 1 coat over the natural if you wanted. You were fortunate to have the engraved, not the silk screened brass logos. The engraved ones can be polished, not so much the silk screened. And personally I wouldn't bother with the lacquer--they'll still tarnish UNDER the lacquer and you'll go through that whole process again. Instead, use Gene's grandma's advice and rub just a drop of olive oil on them. You may have to repeat once a year or so. Great work and a wonderful gift. Now what are the receivers and TTs in the queue? Happy New Year! -Kent Hi Kent, In the rush I'll probably initially give her a modern HK 3390 receiver and a somewhat modern BSR 1200XL computerized fully automatic linear tracking TT. That's just to get her by until I can get her a proper vintage setup. These newer units both work reliably and I don't have anything vintage that is ready to go at the moment. In the queue that I could give her once done are: Receivers: (Seriously thinking about the Realistic below though. The vintage is 1972 and I've tried it and it sounds really good, but needs some work._ the AR-17 doesn't have Loudness so I don't think it will sound good with the AR's at low level even if I can get it working its' fullest.) - Kenwood TK-66 (This one is currently DOA. Just tried it power it up yesterday for the first time. Lights, but no sound. Selector control is frozen. I didn't dig deeper.) - Heathkit AR-13A (Working, but will need a full recap and cleaning. The volume is about half of what I'd expect and it doesn't have "Loudness" which I personally prefer. I actually have two of these. Both have walnut cases. Beautiful units to look at with separate AM and FM dials side-by-side. Just wish they had loudness.) - Heathkit AR-17 (Needs a complete recap. Don't remember if it works. Probably a little too lightweight. I think this is about 10wpc. I actually have two of these.) - NAD 7020 (Needs a cleaning, recap, and bass control replaced. These have a gazzilion electrolytics in them too. The FM is drifting. I'm hoping the recap will fix that.) (This unit would pair really well with the AR's, but I am thinking it isn't "vintage" enough.) - Knight KU45A Tube Receiver (This is a basket case, but powers on and gives some sound.) (Not sure she's ready for the responsibilities of having a tube unit - even if it was ready to go (which it is definitely not.) - Realistic STA-120B (Very dirty and controls need total cleaning. Needs a full recap. It has a walnut case though. I just picked this up a few days ago for $20 and plugged it in yesterday. If I can get the controls all cleaned and working and do the recap this would be a dynamite driver for the AR's. I think it's rated at 80wpc which is a bit much, but the AR's sounded good with the short time I had it hooked up.) Turntables: (I'm thinking to give her one of the Dual 1226's.) - Dual 1009 - I've got two in the queue that need a full restoration. - Elac Miracord Model 46 (Realistic badged) - Just picked this up from the same guy that had the AR-4X speakers for $25. It is complete with 33 changer spindle, but needs a complete cleaning, lube and refurb. This might become my daily driver over the Dual's. - Dual 1226 - I've got two now. One I'm using that needs the plinth fixed. The other needs a complete refurb with cleaning, lube, steurpimple, etc. (Thinking to give her the one I am currently using and swap out one of the plinths for the unit in my queue and maybe swap out the cartridge. Hate to give her my only working changer, but she's family.) There are others in the queue such as a couple of tube Fishers and a Dynaco ST-70, but they're going to stay at home until she (and/or her brother) inherits them in the far future. I've got some low rent Technics separates and a low power Superscope amp from the late 80's that I was going to "Goodwill" or garage sale. The superscope has a weak channel and I just don't think its worth the effort. I've also got two Realistic STA-795's. One is partly DOA the other is in transit. I buy these cheap and they make good test units at about 40wpc when they are working. They usually go for next to nothing. In fact I gave one to my son last year to drive the KLH 17's I gave him and his wife for Christmas after a similar full restoration. I don't think this is a complete list, but its' a start of what I've got in the queue.... BTW Quote Link to comment Share on other sites More sharing options...
ra.ra Posted December 31, 2017 Report Share Posted December 31, 2017 This project was such a pleasure to follow - - - pretty much a soup-to-nuts restoration with a two-week deadline to meet. Your summary was terrific, Tim, and you made many very sensible decisions along the way. Also, your questions were clear and concise and the pics allowed us to follow almost every step. Your final results look really great, and you've picked a couple very fine LP's for the initial audio test drive. I would probably enjoy following this 4x project in any case, but this one is made more special because of the father-daughter gift intent. Please give us a follow-up if there is anything further to report down the line. Quote Link to comment Share on other sites More sharing options...
Tim D Posted December 31, 2017 Author Report Share Posted December 31, 2017 1 hour ago, ra.ra said: This project was such a pleasure to follow - - - pretty much a soup-to-nuts restoration with a two-week deadline to meet. Your summary was terrific, Tim, and you made many very sensible decisions along the way. Also, your questions were clear and concise and the pics allowed us to follow almost every step. Your final results look really great, and you've picked a couple very fine LP's for the initial audio test drive. I would probably enjoy following this 4x project in any case, but this one is made more special because of the father-daughter gift intent. Please give us a follow-up if there is anything further to report down the line. Thanks ra.ra for the kind words. I will most definitely follow-up with any news, but the speakers are basically done now. All that is left is to give them away and mate them with the right equipment. I enjoyed doing these so much, now I need to find a pair for myself. If only I could get another deal like that! Quote Link to comment Share on other sites More sharing options...
lARrybody Posted January 2, 2018 Report Share Posted January 2, 2018 Congratulations on a job well done. Those 4x's are really nice. Did not realize till near the end of this thread that you are obviously a vintage stereo guy. I like your choices on the turntables. Those German idler drive turntables are really nice, especially when you get the balance between the lubrication and the friction correct. On the receiver I also like the Realistic receiver. I have a real nice STA-860 my nephew recently gave back to me because he wanted something with a remote control. What does he know? Almost any vintage 20-40 watt receiver is going to sound good with those speakers. Some that come to mind are the Marantz 2230, Harman Kardon 630 and Pioneer 780. Good luck with those turntables. Quote Link to comment Share on other sites More sharing options...
Tim D Posted March 25, 2020 Author Report Share Posted March 25, 2020 On 12/31/2017 at 1:47 PM, Tim D said: Thanks ra.ra for the kind words. I will most definitely follow-up with any news, but the speakers are basically done now. All that is left is to give them away and mate them with the right equipment. I enjoyed doing these so much, now I need to find a pair for myself. If only I could get another deal like that! Well, it took 2 years, but I finally found a pair for myself! Got a decent deal on the goodwill site, but they are missing one grill/badge and both tweeters have obviously been replaced with one of the phenolic ring tweeter (PRT) types. For the grill, I have managed to find an older set of two grills w/badges and those have been ordered (not yet arrived). It was one more grill than I needed, but having extra is fine. The badge that came with the speakers has the logo printed on top of the badge in black paint and it is not the engraved version with red paint on my daughters set. The serial numbers are not too far apart, but not nearly consecutive. The veneer is decent but there are the usual corner dings and light scratching. They appear in better condition than my usual catch. The cabinets will be an easy refurb. The sheets on the back are not great but not terrible either. It came with the same mounting hardware that was also on my daughters set but positioned differently. I have a Fisher KX-200 amp in the queue right now getting a total overhaul, but when that's done I'll do a full refurb on these AR-4X's. I hope to find two original tweeters and have a line on one that is almost $50 with shipping, but if anyone could point me to information on how well the PRT's work on these I'd appreciate it. If I hear that the phenolics can sound really good I might just keep them for now. Also, is there a difference between the PRT's from different suppliers that are out there? Do I need to pull mine out and see which ones I have? Here are some pics. Quote Link to comment Share on other sites More sharing options...
DonT Posted March 26, 2020 Report Share Posted March 26, 2020 Nice! And with the virus craziness you have time to do what you want to them. Quote Link to comment Share on other sites More sharing options...
Tim D Posted March 26, 2020 Author Report Share Posted March 26, 2020 Wish I had the time. Still working from home and busy as heck. I have the Fisher amp in the queue ahead of it too. Anyway, once I get into it I'll have to determine if the pots are salvageable or not. Quote Link to comment Share on other sites More sharing options...
DonT Posted March 27, 2020 Report Share Posted March 27, 2020 23 hours ago, Tim D said: Wish I had the time. Still working from home and busy as heck. I have the Fisher amp in the queue ahead of it too. Anyway, once I get into it I'll have to determine if the pots are salvageable or not. The pots should be salvageable. I literally just did this one on my AR 2A's. It was totally corroded. I cleaned it back down to shiny brass and then applied dielectric grease to keep it from happening again. Quote Link to comment Share on other sites More sharing options...
Tim D Posted March 27, 2020 Author Report Share Posted March 27, 2020 1 hour ago, DonT said: The pots should be salvageable. I literally just did this one on my AR 2A's. It was totally corroded. I cleaned it back down to shiny brass and then applied dielectric grease to keep it from happening again. So the pitting wasn't a problem with the restored pots? Interesting. I have two of them from refurbing my daughters units. I also have the red plastic post types in my latest set. Maybe I can refurb the pots instead of going with the Lpads this time. Quote Link to comment Share on other sites More sharing options...
DonT Posted March 27, 2020 Report Share Posted March 27, 2020 34 minutes ago, Tim D said: So the pitting wasn't a problem with the restored pots? Interesting. I have two of them from refurbing my daughters units. I also have the red plastic post types in my latest set. Maybe I can refurb the pots instead of going with the Lpads this time. Yes if you use a very fine grit grinding wheel with a dremmel you can polish off the pitting and get down to solid brass again. Quote Link to comment Share on other sites More sharing options...
DonT Posted March 27, 2020 Report Share Posted March 27, 2020 8 minutes ago, DonT said: Yes if you use a very fine grit grinding wheel with a dremmel you can polish off the pitting and get down to solid brass again. I got good it this from rebuilding extremely old switches in antique fans that I collect. I have fans that are 130+ years old and they work great. Here is one I restored. An Emerson model 1510 from about 1909. The blade switch in the bottom has to have the contact points polished to make proper connection again. All I know is there isn't any brass that can not be re polished again even if it is pitted. Quote Link to comment Share on other sites More sharing options...
Tim D Posted March 28, 2020 Author Report Share Posted March 28, 2020 Well then I have two sets of the old pots. I'll have to see if I can salvage them all with that info. Thanks! Quote Link to comment Share on other sites More sharing options...
Tim D Posted May 3, 2020 Author Report Share Posted May 3, 2020 Well, the grills came and they have the engraved badges. Yeah! The badges are in pretty rough shape. Only time will tell what is needed to refurb those badges. Also was able to obtain a trio of original tweeters from an AK member. Yeah! I haven't ordered pots or caps yet as I haven't opened them up yet to determine what's needed. Quote Link to comment Share on other sites More sharing options...
genek Posted May 3, 2020 Report Share Posted May 3, 2020 The pots in early AR models like the 2a had formed brass wipers and coil springs. Most pots in later models have wipers made of spring steel with tinning or copper plating. As those wipers corrode, the pitting eats holes into the steel and eventually the contact tip just crumbles away. If you catch it early enough you may be able to extend the life of the wiper by retinning it with high heat silver solder, but if you only clean it, in a year or two you'll be right back where you were before you opened up the cabinet. Quote Link to comment Share on other sites More sharing options...
Tim D Posted May 26, 2020 Author Report Share Posted May 26, 2020 On 12/17/2017 at 1:01 PM, ra.ra said: Hi TimD. You've got a nice pair of 4x's there, and everything looks original and complete - - great deal for $75. The only thing that looks curious is that curlicue thingy which appears to connect terminal 1 and B on the back of the control pot (BTW, these are original Aetna-Pollak potentiometers, not L-pads). What is that thing-a-ma-bob? Am I seeing this correctly? You'll get all sorts of advice about the cabinets, but those should clean up real nice. It's just a matter of how much time and work you want to invest - - just refresh the existing finish, or sand/remove and then apply new oil finish. Just my opinion - - I like the Danish oils a lot, but I tend to avoid the Dark Walnut - - I like it when the walnut shows an occasional blond streak, and also like to highlight the reddish tones that are in some pieces of veneer. And yes, those grille cloths will also clean up nicely - - while I've had good results with diluted bleach applications, others have shared other successful methods for restoring these to a lighter shade. Can't quite tell from your pics, but if your badges are the incised type with the reddish "AR", they are easy to polish and restore. If they have the "AR Inc" in black - - this version is more delicate and are difficult to brighten without damage to the lettering. Woofers look good, and cloth surrounds with semi-transparent dust cap is all normal. Tweeters look good, and some rust on face plate is also normal. These can clean up easily. For my own projects, I typically remove most everything and work on the various components separately - - cabinets with no drivers; and drivers and pots removed from the cabinets Tightly packed fiberglass stuffing in wads is also normal, and the tissue-like separation sheet under the woofer looks to be in good condition - - it merely keeps the FG from getting into the back of the woofer. The speaker hangers are indeed original parts supplied with the speakers for use as an owner option - - I used them once for a wall-hanging installation and they were sufficiently capable. Just remove them if they will not be used this way. And I don't think the 4x was ever furnished with knobs on the control stem, but they could always be added - - my early AR-4's have knobs, but I've never seen them on 4x's. Also, your pot control stems are the metal version, which is slightly preferable to the plastic ones. These pots will need to be disassembled in order to evaluate them properly - - then you'll be better informed on whether to restore the originals or find replacement parts. I've re-built several pairs of 4x's but never with s/n's as high as yours, and have never encountered that exact capacitor. The Sprague Compulytics tend to be very good and often hold their value even 45 years later, but they need to be measured "out of circuit", and it is more typical for aged caps to increase in value. You can always just replace them anyway, but you may want to re-measure before deciding to do so. Yes, 20uF is the correct value, and if you do opt for replacement, you will get many opinions and suggestion for replacement caps. Lastly about the cabinet sealing. It is not generally necessary to dope the surrounds of the 4x woofer, but if you use the correct sealer, it will not hurt to do so - - I tend to apply a light application as I feel it helps to refresh the pliability of the cloth surround. Those white foam gaskets might be suitable for one more install, but you'll feel better if you use fresh material when re-installing the drivers - - there are several good options for doing this, but I don't like seeing these gaskets squish out beyond the driver perimeter. Pic attached is my pair of 4x using the same woofer as yours. I hope some of this is helpful. Your daughter's gonna love these - - what a great gift! Good for you, Dad. Hey Ra.Ra, How did you get the black color on the front baffles to look so nice? Tim D Quote Link to comment Share on other sites More sharing options...
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