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    Clarification of values?

    I have been reading so much information about ele caps and think my brain is on overload/shut down mode. LoL My main concern is that I do not want to alter the amplifier specifications in any manner that will adversely effect their circuitry and operation.
    I am going to be replacing a lot of electrolytic caps (~250) and could use a little clarification on the more technical parameters.
    (Low IMP, Long Life) Needs to be <= Orig IMP? While Ripple Current needs to be >= Orig values?
    What if ESR isn't given by the manu?? Where do I go from there?
    (General Purpose ELE caps) basically new caps have to be >= V/uF and Ripple Current is >= Orig?

    #2
    Re: Clarification of values?

    capacitance should match,
    voltage should match or be close - but never lower.
    ripple current must never be lower, it can be as high as you like.
    esr must match or be a bit lower - never higher.

    Comment


      #3
      Re: Clarification of values?

      What if you can't find any information about the ESR? I honestly can't find any data sheets on one series of caps I have. I have contacted the manu multiple times with no response and have scoured the net to the best of my abilities.
      And thank you for your response!!
      The cap I can't find is a SamWah 25V 2200uF (RX) series. 16mm X 25mm D X L
      Last edited by Akashajeep; 09-08-2018, 03:47 PM.

      Comment


        #4
        Re: Clarification of values?

        If the capacitor is used in a switching power supply or somewhere high frequency is involved, ESR will pretty much be equal to impedance (the differences are so small they can be ignored), so you can look in the datasheet at the column which says "impedance @ 100khz and [some positive] temperature"

        If the datasheet has no such column then it's either a general purpose capacitor or a capacitor for "audio" or other specialized purposes, basically not a capacitor that should be used in a location where ESR would matter.

        Audio amplifiers and audio circuits can have plenty of general purpose capacitors or capacitors that don't need very low esr - in fact some "audio grade" capacitor series are "designed" on purpose in a way that supposedly makes sound better but on paper the specifications are worse than other series.

        In general capacitance should match. if you know what you're doing, in switching power supplies you can often go "a step" up (basically +20% or so) like from 1200uF to 1500uF.

        in most locations in an audio amplifier circuit, especially if it's an older class AB or something that's not digital, capacitance is often very important to remain the same, as can be part of filtering analogue audio - changing the values can reduce bass or highs or can cause oscillations at some points.

        Ripple current should be as high as old capacitor or higher. My personal opinion is that if you don't have a lot of choices and you find something that's within 5-10% of the old capacitor's value, you'll probably be fine, especially if it's from a reputable brand.

        ESR should be as close as possible or withing 5-10% or so ... basically if the ESR value was 8 mOhm and you find something that's 10 mOhm ... it should be fine. it would not be fine to use one capacitor that has esr value of 15..20 mOhm and may not be fine to use one capacitor that has esr equal to 5mOhm (a polymer capacitor for example)
        Slightly less ESR is often acceptable, but don't go overboard - ex if old capacitor is 12-15mOhm, circuit may not like 6-8 mOhm capacitors.

        voltage rating... must be equal or higher, unless you know what you're doing and you know what the voltage needs. For example, in the vrm circuit for a processor on a motherboard you often see elecrolytic capacitors rated for 6.3v even though the output voltage is almost never higher than 2v - they use 6.3v rated capacitors because their ESR is much lower, not because the higher voltage is required.

        In some computer power supplies, you often see 10v rated electrolytic capacitors filtering the 3.3v and 5v outputs even though 6.3v electrolytic capacitors would have been fine. They often do this because the diameter of the 6.3v and 10v rated capacitors was the same but the 10v ones are slightly taller so there's more surface and therefore the fan can cool them better and so they have a slightly longer life. If you know this and you have to replace them, you could replace these with 6.3v capacitors without any worry.

        The ESR of capacitors often varies with the volume of a capacitor. Also bigger capacitors typically handle voltage better.
        So for example, if you need a capacitor that must have some ESR and you can't find one suitable, but you can find a capacitor rated for slightly higher voltage and just a bit taller with a suitable ESR then you can safely go for one.

        For example, say you have a 1000uF 16v capacitor that's 8mm diameter and 12mm tall and can't find a replacement - you may find a 1000uF 25v rated capacitor that's 8mm diameter and 16mm tall - if height is no issue than higher voltage rating is no problem.

        Comment


          #5
          Re: Clarification of values?

          THANK YOU VERY MUCH for taking the time to explain and write that! I'm unsure of what I can do to repay the favor? Your explanation "made me see the light at the end of the tunnel"! THX

          Comment


            #6
            Re: Clarification of values?

            Attached Files

            Comment


              #7
              Re: Clarification of values?

              IDK where or how you found that but, THANK YOU very much!!! I have hunted, scoured, contacted, backtracked, and could not for the life of me find that one LoL Really, Thank You!!

              Comment


                #8
                Re: Clarification of values?

                was here, in Palastine.
                http://www.harzion.co.il/,products,25

                took me about 2 minuits - google is NOT your friend.
                use duckduckgo and yandex search engines.
                Last edited by stj; 09-09-2018, 05:20 AM.

                Comment


                  #9
                  Re: Clarification of values?

                  Originally posted by stj View Post
                  was here, in Palastine.
                  http://www.harzion.co.il/,products,25

                  took me about 2 minuits - google is NOT your friend.
                  use duckduckgo and yandex search engines.
                  Indeed GooGle IS NOT! LoL
                  I will be adding those to the search bar from now on!!!! THX
                  I knew there was a site I had seen that had that sheet, and I could have sworn I snaged it, but knowing me it was 4 A.M. and I had 20 different pages open HAHAHA Even though it doesn't give the exact specs for this "one-off series I guess", with all of the other information I have received from you guys, I'm sure I can get it in the ballpark. All of the caps in these amps are <= 25mm tall.

                  Once again, I greatly appreciate all of the help and knowledge!!

                  Comment


                    #10
                    Re: Clarification of values?

                    If you use google and just type in 'Samwha rx series" and 'samwha miniature aluminum electrolytic capacitors rx - אלקטרוניקה הר, www.harzion.co.il/,products,show_968
                    If you type in 'Samwah rx series' then you will not not get that website.
                    'SamWah 25V 2200uF (RX) series'
                    BTW, can we see what kind of product, circuits we are dealing with?
                    Last edited by budm; 09-09-2018, 05:02 PM.
                    Never stop learning
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                    Comment


                      #11
                      Re: Clarification of values?

                      We have here X3 JBL 80.4 class A/B amps and one JBL 1200.1 Class D
                      YES I know the "ground strap" is off. They will all have to be taken apart AGAIN....... Once I get the caps shipped. :-( I would really like to upgrade the 80.4's in both power output and clarity, however, I'm not skilled enough in that department.
                      Attached Files

                      Comment


                        #12
                        Re: Clarification of values?

                        Originally posted by Akashajeep View Post
                        What if you can't find any information about the ESR? I honestly can't find any data sheets on one series of caps I have. I have contacted the manu multiple times with no response and have scoured the net to the best of my abilities.
                        And thank you for your response!!
                        The cap I can't find is a SamWah 25V 2200uF (RX) series. 16mm X 25mm D X L
                        If you're really located in the USA ("Over the Rainbow" ), don't bother with buying cheap crap cap brands like SamWah/SamWha/Sam..whatever.

                        Only go for quality Japanese brands like Panasonic, Rubycon, Nichicon, and United Chemicon. And only use reputable parts sources, such as Digikey, Mouser, and badcaps.net/store.

                        eBay, Amazon, and AliExpress are usually NOT good sources for genuine Japanese caps, so avoid those (most likely, you will get a counterfeit from China/Taiwan/Hong Kong that will fail very quickly).

                        **EDIT**
                        Oh I see... looks like SamWha and SamYoung (among other crap brands) is what you currently have in your amp. Shame on JBL! At least they didn't use crappier brands like CapXon, Decon, Xunda, Cheng/Chang/Chong/X (I'm looking at your, Behringer! )
                        Last edited by momaka; 09-12-2018, 04:41 AM.

                        Comment


                          #13
                          Re: Clarification of values?

                          dont be too hard on Behringer, they are just trying to keep up with Harmon Kardon!

                          Comment


                            #14
                            Re: Clarification of values?

                            "Over the Rainbow" is just a reference to the 1939 film, The Wizard of OZ. At times I feel as if I am on the other side that no one can ever see :-(

                            I couldn't agree with you more, JBL/Harmon/Crown should have known better, however, this series (P & BP) are considered the "prototypes" for the "Crown Designed & Engineered" models that followed the next year. The Crowns use better parts and are laid out differently for a more aesthetically pleasing appearance, but it is the same design, except with a higher price tag and flashy neon tubes lol.
                            As far as the replacement caps go, I have been looking at mostly ELNA Silmics II's as well as Nichicon FG, KA, and KW's for MOST of them. Obviously, FG's won't work for a low Z High V/uF replacement. For now, I'm just trying to connect the dots and cross the T's ;-)

                            Once again, I do GREATLY appreciate everyone's help with making me competently understand what their values mean and how to improve those that desperately need attention.

                            Comment


                              #15
                              Re: Clarification of values?

                              Originally posted by Akashajeep View Post
                              As far as the replacement caps go, I have been looking at mostly ELNA Silmics II's as well as Nichicon FG, KA, and KW's for MOST of them. Obviously, FG's won't work for a low Z High V/uF replacement. For now, I'm just trying to connect the dots and cross the T's ;-)
                              I don't recommend going with those audio-grade caps on the high-speed switching sections (i.e. the inverter) of those amps. Just get regular low-ESR 'lytics. Only the small caps that carry signal you can go with Nichicon FG, KA, and KW's. (Not that you will see a difference in performance, but why not when some of these are priced close to regular GP caps).

                              Originally posted by stj View Post
                              dont be too hard on Behringer, they are just trying to keep up with Harmon Kardon!
                              Hehe.

                              On a second note, JBL did use CapXon (and Su'scon) in some of their older (early 2000's) active floor speakers. Just remembered I repaired a set last fall for a guy, and it was full of CapXon GS. Most were high ESR. But the fella that caused all the issues was a big CapXon GS 4700 uF cap (completely open-circuit and leaking from one leg). Then again, the guy with these speakers said they provided him with over 15 years of service, so maybe not too terrible on CapXon's part. JBL also had lots of design goofs on the bass amps of those speakers, which is likely what caused that big CapXon cap to fail (58-60V DC on a 63V-rated cap is a bit too close in my book, design-wise ).

                              Originally posted by Akashajeep View Post
                              "Over the Rainbow" is just a reference to the 1939 film, The Wizard of OZ.
                              Ah, I see now.
                              I never managed to be able to sit down and watch that movie.
                              For those of you who say that this is one of the best American movies... all I say is Pulp Fiction
                              Last edited by momaka; 09-12-2018, 07:17 PM.

                              Comment


                                #16
                                Re: Clarification of values?

                                Originally posted by momaka View Post
                                I don't recommend going with those audio-grade caps on the high-speed switching sections (i.e. the inverter) of those amps. Just get regular low-ESR 'lytics. Only the small caps that carry signal you can go with Nichicon FG, KA, and KW's. (Not that you will see a difference in performance, but why not when some of these are priced close to regular GP caps).:
                                Even with the "High End" caps, I'm finding it kind of hard to get close to the RC values of the originals. That is unless I step into the 50/100V ranges. Little buggers have some juice flowing through them LoL. There are twelve 16V/100uF (RC of 211 mArms) per 80.4 and seven in the 1200, which totals 43. This is going to get expensive quick!! LoL Oh well, I figure do it now and get another 15+ years out of them.

                                Comment


                                  #17
                                  Re: Clarification of values?

                                  Well, truth be told, the only caps that are likely to fail and cause a big issue are those big caps on the inverters. Unfortunately, it's also these caps that are the most expensive. Once you commit to purchasing those, the small caps will be pretty much "pocket change".
                                  ... or maybe not, given how many small ones you got.

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