JKent Posted April 20, 2019 Report Share Posted April 20, 2019 I was asked to refurbish these Twenties and eliminate the RCA jack. Haven't got around to the cabinets yet--that will wait for better weather. Grilles are a little stained so they may need new cloth. Tackled the crossovers today. Crushed the RCA jacks and pried them off then attached wood paint stirrers to provide a stable backing and non-conductive mounting for the 5-way binding posts. Caps are one 8uF Ulta-Cap and two 2uF Swedish Rifa Miniprint caps per xo The Rifas were from an AK member at Glenn's 2018 Blue Mountain Lodge gathering. FWIW, the original Rogers LS3/5a speakers used Rifa Miniprint capacitors. I did check the old caps. They're the familiar black & red. Not Callins but Whale. I was amazed to find every cap was within spec. I think the worst one was a 2.0 that measured 2.3uF. But they're little ticking time bombs and for the approximately $5 per speaker cost I'm happy to have nice new film caps in there now. More photos will follow when the cabinets are finished. Quote Link to comment Share on other sites More sharing options...
fran604g Posted April 20, 2019 Report Share Posted April 20, 2019 ? hmmm...I have a pair of these stashed. Never tried them out. How might they compare to something like the Lg. Advents? Quote Link to comment Share on other sites More sharing options...
JKent Posted April 20, 2019 Author Report Share Posted April 20, 2019 Similar I suppose. A little less bass. And they're 4 ohms. Quote Link to comment Share on other sites More sharing options...
RTally Posted April 21, 2019 Report Share Posted April 21, 2019 8 hours ago, fran604g said: ? hmmm...I have a pair of these stashed. Never tried them out. How might they compare to something like the Lg. Advents? I suggest you try them out. You might be surprised. I have a pair of Model Twenty's that I recapped and added binding posts, similar to what JKent did. I also have a pair of OLA and had a pair of NLA and Advent/1 and Legacy II. I like the 20s better, even if the OLA may dig a bit deeper. Quote Link to comment Share on other sites More sharing options...
fran604g Posted April 21, 2019 Report Share Posted April 21, 2019 9 hours ago, JKent said: Similar I suppose. A little less bass. And they're 4 ohms. 5 hours ago, RTally said: I suggest you try them out. You might be surprised. I have a pair of Model Twenty's that I recapped and added binding posts, similar to what JKent did. I also have a pair of OLA and had a pair of NLA and Advent/1 and Legacy II. I like the 20s better, even if the OLA may dig a bit deeper. Thanks guys, I think I found my next speaker project. Quote Link to comment Share on other sites More sharing options...
JKent Posted May 2, 2019 Author Report Share Posted May 2, 2019 Finished. The cabinets still have some scratches (patina ?) but I don't want to sand the veneer too aggressively. Filled chips and corner dings with epoxy/Mixol 22. Used Howard Restor-a-Finish Mahogany to even out the color on the cabinets and when that was thoroughly dry (a couple of days) I used 2 coats of Watco Danish Oil, Walnut. The woofer surrounds got a coat of Roy's goo per Service Bulletin 60 http://www.classicspeakerpages.net/library/klh/other/klh_schematicsservice/klh_service_bulletin_60.pdf That really improved the "3-finger" test. I tried to clean the grilles with upholstery spray cleaner and oxy-clean but the stains didn't come out and new ones were created where the black scrim cloth bled through so I replaced them with some nice Irish Linen. Spray painted the Masonite black first, both to mimic the original appearance and seal it. The Masonite is too thin to staple so I glued the linen on with Aleene's Tacky Glue. No scrim--why put extra layers of clothe between the drivers and your ears? After the glue was dry I sprayed the linen with water, dried it with a hair dryer so it's nice and tight. Then gave it a coat of Scotchgard. Finally installed a pair of my reproduction logo plates. I'm happy with the result and they sound good! Quote Link to comment Share on other sites More sharing options...
Martin Posted May 12, 2019 Report Share Posted May 12, 2019 Nice work! Has anyone actually measured the impedance of a KLH 20 to see if it is different from that of a 17? Perhaps the woofers are different even though they look the same. Quote Link to comment Share on other sites More sharing options...
JKent Posted May 12, 2019 Author Report Share Posted May 12, 2019 3 hours ago, Martin said: Perhaps the woofers are different even though they look the same. Yes. The 17s are 8 ohm, the 20s are 4 ohm. Tweeters and crossovers are the same. Only the woofers are different. Quote Link to comment Share on other sites More sharing options...
fran604g Posted March 3, 2023 Report Share Posted March 3, 2023 It only took 4 years give or take a couple weeks, but I finally brought the Model 20s down from the attic and serviced them. All went well, and I'm quite happy with the results. On 4/20/2019 at 6:54 PM, JKent said: Similar I suppose. A little less bass. And they're 4 ohms. @JKent you were dead on. There isn't much going on below about 47Hz, but the rest is there, and the signature "AR" sound is nice. I'm using them in my barn being driven by a Topping TP60 chip-amp with an old XP PC for the music files running JRiver. Perfect for my particular application. Thank you all for your help (again) all of these years (decades. really)! Quote Link to comment Share on other sites More sharing options...
JKent Posted March 5, 2023 Author Report Share Posted March 5, 2023 Cool! Love the old trucks. I'll have to look into JRiver--never heard of it before. Quote Link to comment Share on other sites More sharing options...
fran604g Posted March 6, 2023 Report Share Posted March 6, 2023 20 hours ago, JKent said: Cool! Love the old trucks. I'll have to look into JRiver--never heard of it before. Thanks, they were my wife's a loooong time ago. I've been using JRiver Media Center v.18 for years. I think I started using an earlier version by around 2007-8 when I built my first PC server for our home and upgraded when MC18 came out. I've only used it for my Wi-Fi music server, no video or online streaming services. I like it, it's versatile and has substantial DSP/DSD capabilities above my pay grade. Quote Link to comment Share on other sites More sharing options...
RoyC Posted March 6, 2023 Report Share Posted March 6, 2023 On 3/3/2023 at 6:39 AM, fran604g said: and the signature "AR" sound is nice. I'm using them in my barn being driven by a Topping TP60 chip-amp Gonna have to get me a pair of those KLH AR's. 🙃 I use an older Topping in the shop for testing speakers. Works very well... Roy Quote Link to comment Share on other sites More sharing options...
fran604g Posted March 6, 2023 Report Share Posted March 6, 2023 Did I put the cart in front of the horse a bit too much?😁 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.