Replacing caps in SL3s.

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ck102020

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My SL3s are nearing in on 25 years. They still sound great all around but I never heard them during their early days. I bought them a year and a half ago. Apart from panel replacement and woofer replacement, I have heard a lot mentioning that caps should be replaced. I am planning on replacing the panels in the near future and want to keep the original woofers. How do I go about new caps or anything else that may be limiting performance due to the age of the speakers?

Also, what are the best way to transport Martin Logan speakers? Is it best to remove the panels? Thanks for any advice!
 
Hi CK
Sounds a lot like what I’ve done with the Odysseys I bought. New panels and I also replaced all the woofers with drivers of my choice. I also disconnected the passive factory crossover to the woofers and went to active crossover. I now have all new capacitors for the panel factory crossover section, I’m in the process of deciding if I want to install them or leave things the way they are now. The speakers sound excellent now, and when you change the capacitors it will change the sound of the speakers whether that change is for the better or not will only be determined by the listener after the caps have been changed. My thinking is I can change out the caps and see what I think about the sound and if I don’t like it put the original caps back in.
As far as transporting your speakers I bought mine in the Chicago area and picked them up there and transported them back home to the Detroit area in my Silverado, I used harbor freight moving blankets to wrap the speakers in as they had no original boxes. I laid them on their sides with the panels facing each other. It makes it real nice with a pick up and bed cover.
 
Hi CK
Sounds a lot like what I’ve done with the Odysseys I bought. New panels and I also replaced all the woofers with drivers of my choice. I also disconnected the passive factory crossover to the woofers and went to active crossover. I now have all new capacitors for the panel factory crossover section, I’m in the process of deciding if I want to install them or leave things the way they are now. The speakers sound excellent now, and when you change the capacitors it will change the sound of the speakers whether that change is for the better or not will only be determined by the listener after the caps have been changed. My thinking is I can change out the caps and see what I think about the sound and if I don’t like it put the original caps back in.
As far as transporting your speakers I bought mine in the Chicago area and picked them up there and transported them back home to the Detroit area in my Silverado, I used harbor freight moving blankets to wrap the speakers in as they had no original boxes. I laid them on their sides with the panels facing each other. It makes it real nice with a pick up and bed cover.
Isn’t the panel factory crossover section replaced when replacing with new panels? I haven’t heard of that talked about much here. I was under the impression that the only thing to replace are the panels, woofers, woofer crossovers, and the seal of the woofer grill. I’d love to know more about this process as I don’t seem to understand it. Thanks so much for your response it was very helpful!
 
I put new panels in my SL3's about 18 months ago, and that was great of course. And then about 6 month later, I upgraded the old caps. The original main panel caps were a 15uF electro + 15uF yellow film cap (shown in pic). I replaced those with a pair of 15uF Jantzen Z-standards from Parts Express. I also replaced the 330uF, with a new electrolytic and a bypass cap. Sorry, I cannot find my pic of the completed mod! Anyway..... the difference was significant. The highs are brighter and more open. So much so, that I had to switch amps. My Bryston 4B-ST was now too bright (and it is a bright amp), and I switched to a 4B-SST2, which has more neutral highs. I'm still running the stock woofers. They are in fine shape, and I'm afraid to fix what ain't broken! While new woofers might work, I've not heard for certain that the new recommended woofers are, in fact, better than the originals.
 

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That’s good to know Mirolab, I have a combination of Mundorf EVO Aluminum oil caps and Jantzen Superior Z caps to replace my Odyssey panel crossover caps with. Now you have me wanting to hear the difference in my Odysseys, thanks for that post
 
That’s good to know Mirolab, I have a combination of Mundorf EVO Aluminum oil caps and Jantzen Superior Z caps to replace my Odyssey panel crossover caps with. Now you have me wanting to hear the difference in my Odysseys, thanks for that post

I'm a big fan of the Mundorf EVO Oil caps. I've used them in a number of speaker rebuilds. I've always found them very clean and transparent, with a palpable presence in the midrange. All of my old Acoustic Research speakers now use them. I'm also recapping my ML EM-ESL's now, and I'm using a combination of Mundorf Supreme EVO Oils and ClarityCap CSA's in those. I look forward to hearing the finished results...!

Good luck.
 
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Mundorf EVO Oil caps

I'm assuming you are using the Mundorfs as a small bypass cap, right? Have you tried with & without them, and really notice a difference? I'm wondering because I've already got the Jantzens in place.... adding a 1uF EVO bypass would be easy and affordable. Is this worth doing? Or should I spring $$ for the full 30uF's?
 
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I'm assuming you are using the Mundorfs as a small bypass cap, right? Have you tried with & without them, and really notice a difference? I'm wondering because I've already got the Jantzens in place.... adding a 1uF EVO bypass would be easy and affordable. Is this worth doing? Or should I spring $$ for the full 30uF's?

My EM-ESL's use Mylar 22uF and 39uF caps. Electrolytic caps are 68uF and 180uF. So, I "assume" the Mylar capacitors are series caps, and the electrolytics are shunts? I wish I could find a crossover schematic to confirm that guess? I'm replacing the 22 with the Mundorf Supreme EVO Oils, and the 39 with ClarityCap CSA's. For the 68uF, I have 68uF Mundorf film MCaps, and I guess I'll use a new 180uF electrolytics with a Dayton Film and Foil 0.1uF bypass caps. Solen makes 180uF film caps, but I expect they're huge! Not that the other caps I've picked-up are exactly small...!

I've tried bypass caps on several speaker recaps, and I like them. I mainly use them along with electrolytics, but I've tried them on poly caps too. Bypass caps (to me) help smooth and balance the sound, along with improve micro dynamics. That helps bring out small details in the music. Cheap enough to try.

If interested in further reading on capacitors, check out the Humble Homemade Capacitor Test site. Very good reviews on various brands of capacitors, and of the cap brands I've tried from those tested, my sonic impressions closely match to what the reviewer is reporting.
 
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Stimpywan, that last paragraph is spot on I use that Humble Homemade Capacitor Test site all the time, it’s a valuable research tool for caps. Good call!!!
 
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