Lucky Pierre Posted October 6, 2018 Report Share Posted October 6, 2018 Greetings, I recently picked up a pair of AR-5, s/n K 17388, K 17389. The PO refreshed the veneer, refoamed the woofers, and cleaned the pots on one of the speakers. That speaker sounds great, the other not so much. Weak muddy highs and mids. I am planning on cleaning the pots on the one that wasn't done and recapping both. I have the big, wax block caps. Is there a way to test them in place, or should I just plan on replacing? If I replace, should I cut the wires at the block and leave it in place? Can I use a brass brush on the pots, or should I stick to a salt and vinegar soak? Thanks! Quote Link to comment Share on other sites More sharing options...
ReggaeBen Posted October 7, 2018 Report Share Posted October 7, 2018 Wow! I have to say how fortunate you are to have a consecutive numbered pair, that appears all original, extremely good score! The only real way to measure the caps are to pull at least one wire (two in this case as the wax cap is dual, serving both woffer and mid) then meaure, thus it removes it from the circuit and can be reliably measured. The one to leave connected can be the ground wire, found by using your meter or simply by eye. Unsolder at the rheostats to measure and If you go ahead with recapping then you cut right at the beginning of the wax block to resuse the wires. I cleaned up my rheostats using the salt and vinegar method but as it was my first time ever doing so I'd wait for some other opinions to come through before you decide, so long as all corrosion is removed and genorously protected you can't really lose. Enjoy those 5's.. btw, do download the AR3a restoration guide found here on the site, greatly helpful.. Ben Quote Link to comment Share on other sites More sharing options...
owlsplace Posted October 10, 2018 Report Share Posted October 10, 2018 Very nice, probably from 1971-2 production. There should be some dates on the back of the drivers. The wax double cap needs replacement. Pots are clean, lube or just replace with L-pads and be done with it. Looks like generic surrounds on the woofers which is not the best and I think the #10 coil was an early variation of the xover. I have a blond sequentially numbered pair which was more common although harder to find in good shape Enjoy -- when the 5s were good, they were really good. Downside is they like large amps and have fragile tweeters. Fusing is recommended. Quote Link to comment Share on other sites More sharing options...
Aadams Posted October 10, 2018 Report Share Posted October 10, 2018 The restoration guide has everything you need except advice that was not available about tweeters at the time it was composed. Even if your tweeters operate they will almost certainly need rebuilding to restore the sound to very near original. Your options are 1 the proven Hi Vi replacement mod or 2 a Chris1 rebuild of the originals. IMO above 60hz AR never made a better sounding speaker, especially for human voice or acoustic instrument sound reproduction if all of the original drivers are operating properly. Your original caps are not Sprague Compulytics but appear to be ICC of Chicago. My advice is to replace them. Adams Quote Link to comment Share on other sites More sharing options...
Lucky Pierre Posted October 11, 2018 Author Report Share Posted October 11, 2018 Thanks everyone. Looks like I have to do some more research re: the tweeters. These will be (at least one pair) of my forever speakers. I want to make sure to do things right. Quote Link to comment Share on other sites More sharing options...
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