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    Which capacitor type for which recapping job?

    I have a lot of 80's/90s electronic musical equipment (synthesizers etc.) and a couple of vintage computers from that same era which I want to recap as a preventive measure even though they mostly work fine for the time being.

    Finding quality branded caps (Nichicon, Panasonic, Rubycon etc.) with a long life rating (i.e. 10 000 hours) and high temperature rating (105C) along with the same uF values and equal or higher voltage ratings is also a no-brainer, but apart from that -which type?
    General purpose types, low-ESR, ultra-low ESR..?

    In a separate discussion here, concerning an old (early 90s as far as I know) switched mode power supply for an Atari ST computer I've learnt that it might not be as simple as "just replace all the electrolytics with quality branded low-ESR types", but really, "it depends...".
    So, for a DIY electronics hobbyist like myself, what would you suggest I use when recapping (i'm talking about electrolytics below as I understand I usually don't need to concerned about the other ones) for instance:

    a) caps on 80's/90's computer motherboards (i.e. my Atari ST)
    b) caps inside 80's/90's music synthesizers, drum machines, mixers and other audio related gear
    c) caps on power supplies (not switched mode ones, but the big transformer types with rectifier/filtering boards)
    d) caps in switched mode power supplies (I've discussed this separately already, and it appears to be a complex issues, but I'm still open for learning more on the subject).

    #2
    Re: Which capacitor type for which recapping job?

    a) The shittiest Low ESR cap from a named brand is what you are looking for...
    Panasonic FC at best, probably rather things like Nichicon UPS and similar.
    b) depends on where we are talking about. For the Audio Part, Audio caps, for the rest see A.
    c) see A, but probably rather some good General Purpose ones for Power Supplys.
    d) Define 'Switch Mode Power Supply'.

    Basically what you are looking for are Anhydrous Type capacitors.
    Last edited by Stefan Payne; 07-26-2017, 04:47 AM.

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      #3
      Re: Which capacitor type for which recapping job?

      Well, first of, use only 105C parts. As best I know, there's no benefit in using 85C parts, other than perhaps the price. If you're buy 10s of thousands a month, that's significant. If you're extending the life of legacy equipment, then the extra life/reliability is probably worth a little extra money.

      Beyond that, understand how the part is used and when the circuit was designed.

      For generic decoupling applications, 105C GP parts should be OK. Upgrading to PS or PM or PW (Nichicon series) will be OK, but won't necessarily be an improvement.

      For primary side input caps or linear regulator output caps go with long life, high ripple current types.

      For small caps in the PWM IC circuit or Standby regulator circuit, go with PW, FC, or LXZ. These parts are important, and they probably are stressed.

      For switchmode output caps, go with low impedance parts that are similar or slightly better than what was used or was current at the time the circuit was designed.
      PeteS in CA

      Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
      ****************************
      To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
      ****************************

      Comment


        #4
        Re: Which capacitor type for which recapping job?

        Panasonic seems to be readily available from my dealer whereas Nichicon is harder to find. I'm not familiar with the differences between the different series, so I looked it up at the Manufacturer's site here.
        These are the Panasonic through-hole electrolytic capacitor series I could find with 105C temperature ratings and with the highest hour ratings along with their characteristics (I don't know if they're "anhydrous" as suggested below):

        FS-A 5000-10000 hours (low ESR, miniaturization)
        FR-A 5000-10000 hours (low ESR)
        ED-A 8000-10000 hours (high ripple at high frequency)
        EE-A 8000-10000 hours (high ripple)
        FM-A 4000-7000 hours (low impedance)
        FC-A 3000-5000 hours (low impedance)
        EB 5000-10000 hours (long life, low profile)

        A quick search through my supplier tells me they're all available (though I haven't checked which values or comparing costs) but personally I'd skip the FM-A and FC-A series because of their lower lives.


        Originally posted by Stefan Payne View Post
        a) The shittiest Low ESR cap from a named brand is what you are looking for...
        Panasonic FC at best, probably rather things like Nichicon UPS and similar.
        Not being sure of what's good, better and best I'd guess Panasonic FM-A, FR-A and FS-A (they appear to have the same features) would do, but maybe not their EB-series as there was no mentioned of "low-ESR" for them?


        b) depends on where we are talking about. For the Audio Part, Audio caps, for the rest see A.
        How do I know which caps are "audio caps"? Is there a specific series from Panasonic for this?


        c) see A, but probably rather some good General Purpose ones for Power Supplys.
        How would you rate the above Panasonic series in terms of "Best, better, good, adequate" etc? for general purpose use?


        d) Define 'Switch Mode Power Supply'.
        I'm no expert (as you might have guessed already) but am referring to those power supplies which visually have a small transformer and a lot of complex electronic circuitry and components (as opposed to power supplies with a large transformer and a rectifier/filtering board).
        Specifically I was first of all referring to this SMPS which I believe needs recapping soon (because of its age: around 25 years old) even though it appears to work fine.


        Basically what you are looking for are Anhydrous Type capacitors.
        I had to look up the term "Anhydrous" which according to Wikipedia means they have high temperature ratings, are long lasting and low leakage. There was no mention of low ESR so I assume these are basically "general purpose" high quality capacitors, but believe you might mean that I need to look for anhydrous capacitors in general, and with "low ESR" or "high ripple" capabilities in addition to this where needed, right?
        Last edited by accent; 07-30-2017, 05:00 PM.

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          #5
          Re: Which capacitor type for which recapping job?

          Originally posted by PeteS in CA View Post
          Well, first of, use only 105C parts. As best I know, there's no benefit in using 85C parts, other than perhaps the price. If you're buy 10s of thousands a month, that's significant. If you're extending the life of legacy equipment, then the extra life/reliability is probably worth a little extra money.
          I fully agree. I don't intend to recap my gear more than absolutely necessary.

          Beyond that, understand how the part is used and when the circuit was designed.
          So there's no "failsafe" choice of capacitors (Panasonic preferred as described in my other post because of better availability) for non-engineer types like myself? You really need to understand how the circuit works before recapping?


          For generic decoupling applications, 105C GP parts should be OK. Upgrading to PS or PM or PW (Nichicon series) will be OK, but won't necessarily be an improvement.
          What would this be equivalent to in Panasonic terms?


          For primary side input caps or linear regulator output caps go with long life, high ripple current types.
          Something like Panasonic ED-A (best, because it's defined "high ripple at high frequency) or EE-A (good, because it's only defined "high ripple")?


          For small caps in the PWM IC circuit or Standby regulator circuit, go with PW, FC, or LXZ. These parts are important, and they probably are stressed.
          Something like the Panasonic EB series (which I understand are defined as "general" purpose") or the "high ripple" ED-A or EE-A Panasonic types?


          For switchmode output caps, go with low impedance parts that are similar or slightly better than what was used or was current at the time the circuit was designed.
          That's the tricky part -to figure out the original impedance of obscure, outdated caps, but in a previous posting you suggested Nichicon PM (same as the PL series, but lead-free), PS (same as the PR series, but lead-free) or PJ series for this. You also said I should keep away from Nichicon PW, United Chemi-con/Nippon Chemi-con LXZ series or Panasonic's FC series for this particular use.
          Which of Panasonic's series would be suitable for this? By "switchmode output caps" I assume you're referring to all the (low voltage) caps in the PSU (basically everything except the two 400V types in my PSU schematic)?

          Comment


            #6
            Re: Which capacitor type for which recapping job?

            So there's no "failsafe" choice of capacitors ... for non-engineer types like myself? You really need to understand how the circuit works before recapping?
            ...
            What would this be equivalent to in Panasonic terms?
            Not to the point of being a design engineer or engineering tech, but you should be able to recognize roles that are general purpose or that are stressed.

            Nichicon PW, Nippon Chemicon LXZ, and Panasonic FC are basically equivalents, and all very good. PM and PS are somewhat lower performance and I don't think Panasonic has an equivalent series any more (Nichicon tends to keep older series alive to support existing users longer than do Chemicon or Panasonic).

            That's the tricky part -to figure out the original impedance of obscure, outdated caps, but in a previous posting you suggested Nichicon PM (same as the PL series, but lead-free), PS (same as the PR series, but lead-free) or PJ series for this. You also said I should keep away from Nichicon PW, United Chemi-con/Nippon Chemi-con LXZ series or Panasonic's FC series for this particular use.

            Which of Panasonic's series would be suitable for this?
            I really don't know of a suitable Panasonic series. I don't know if it's any help, but I would add Rubycon's YXF series to the list of older series.
            PeteS in CA

            Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
            ****************************
            To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
            ****************************

            Comment


              #7
              Re: Which capacitor type for which recapping job?

              Originally posted by accent View Post
              FS-A 5000-10000 hours (low ESR, miniaturization)
              FR-A 5000-10000 hours (low ESR)
              ED-A 8000-10000 hours (high ripple at high frequency)
              EE-A 8000-10000 hours (high ripple)
              FM-A 4000-7000 hours (low impedance)
              FC-A 3000-5000 hours (low impedance)
              EB 5000-10000 hours (long life, low profile)
              FM is something you can use if you want to replace smaller Nippon Chemicon KZG. So they are for 'modern' Motherboards (early-late 2000s).
              So if you want to replace a capacitor in a Motherboard VRM of Socket A (and later) or S478 or later, they are indeed an option and a replacement for ultra low ESR types. Sometimes, not always. I've looked at 820uF/6,3V AFAIR, those are equal or better than Nippon CHemicon KZG or maybe Panasonic FJ.
              For you it's not something you want to use due to low ESR.
              Same applies for FR. And also the new FS Series. They are good for modern components, not so much for older ones.
              So not really something for you...

              EE seems like a high voltage series (160V and up) as is ED.
              Not sure about EB Series, they seem to be standard/GP Capacitors...

              That leaves the FC Series wich seem to be the only option for older components.


              Originally posted by accent View Post
              Not being sure of what's good, better and best I'd guess Panasonic FM-A, FR-A and FS-A (they appear to have the same features) would do, but maybe not their EB-series as there was no mentioned of "low-ESR" for them?
              No, they are too good for the things you want to do...
              It may cause Problems like oscilation and other things. Because no engineer thought about those things when they were designing stuff because they were decades from being invented

              Originally posted by accent View Post
              How do I know which caps are "audio caps"? Is there a specific series from Panasonic for this?
              That's easy.
              They are called audio caps

              I think the FM series could be an option for those.
              Here some info from Nippon Chemicon:
              https://www.chemi-con.co.jp/e/tech_t...for_audio.html


              Originally posted by accent View Post
              How would you rate the above Panasonic series in terms of "Best, better, good, adequate" etc? for general purpose use?
              Depends on use.
              From what I've learned it seems that FC is the 'Entry Level', all others are better.
              FM seems to have the lowest ESR
              FR and FS are downsized versions with higher ESR but smaller footprint (sometimes way smaller)


              Originally posted by accent View Post
              I'm no expert (as you might have guessed already) but am referring to those power supplies which visually have a small transformer and a lot of complex electronic circuitry and components (as opposed to power supplies with a large transformer and a rectifier/filtering board).
              Specifically I was first of all referring to this SMPS which I believe needs recapping soon (because of its age: around 25 years old) even though it appears to work fine.
              It's a good idea to recap them even if there doesn't seem to be anything wrong with it.
              The Problem is the age and the use of capacitors. If you have some kind of load, spare PSUs and an osciloscope, you could get a hand full of capacitors and just test it.
              That's the only way to be sure.

              I know CapXon has some 'General Purpose' Series for Power supplys (KM) wich doesn't seem that unreliable. But you might want something from other manufacturers...
              Panasonic does not mention the 'intended usage' of the Capacitors in the Datasheet...



              Originally posted by accent View Post
              I had to look up the term "Anhydrous" which according to Wikipedia means they have high temperature ratings, are long lasting and low leakage. There was no mention of low ESR so I assume these are basically "general purpose" high quality capacitors, but believe you might mean that I need to look for anhydrous capacitors in general, and with "low ESR" or "high ripple" capabilities in addition to this where needed, right?
              Su'scon has some 'anhydrous' Types that seem to have the values that you want. And they mention Anhydrous especially.

              So basically they are rather shitty "low ESR" capacitors. ESR is in the ballpark of the Nichicon UPS. So pretty bad. I wouldn't use them for any modern Power Supply. But for older ones they can be perfect. The SDN seems to be what you want. ESR is really bad and has 52 Ohms for a 2200uF/16V type. FC should be around half that -> 30 Ohms.
              FM/FS/FR are around 18 Ohms.

              But I think the Panasonic FC series would be fine too...

              Comment


                #8
                Re: Which capacitor type for which recapping job?

                Too bad about the hour rating of those Panasonic FC-series.
                I was hoping for 10 000 hours. Are there any other suitable caps from Panasonic I might have missed with 105C and 10 000 (or close) ratings?

                Comment


                  #9
                  Re: Which capacitor type for which recapping job?

                  Originally posted by accent View Post
                  Too bad about the hour rating of those Panasonic FC-series.
                  I was hoping for 10 000 hours. Are there any other suitable caps from Panasonic I might have missed with 105C and 10 000 (or close) ratings?
                  The thing to keep in mind - I know, more details - about the life ratings is that this is what the manufacturer will guarantee, at the parts' maximum rated temperature and ripple current. So in real usage that "5000 hours" will be 10s of thousands of hours (a year is a little under 10,000 hours). So, speaking practically, I would use Nichicon PW, Nippon Chemi-Con LXZ, and Panasonic FC interchangeably.

                  Because no engineer thought about those things when they were designing stuff because they were decades from being invented
                  Exactly! In the early 1990s, Nichicon's PL series (= PM series) and the corresponding Chemi-Con, etc. series were the best available, and circuits were designed around the parameters of those parts. Since that time, Nichicon has produced the PJ series, PW series, (new) PA series, and several series with water-based electrolytes. Chemi-Con and Panasonic have chosen not to keep older series in production (NCC still produces the older LXV series, which is equivalent to Nichicon's PJ series).

                  Going back another 10 years, designers using Chemi-Con's RX series or Nichicon's (old) PA series probably could hardly dream of the performance of the LXZ and PW series. Just try to imagine using an early 1980s microprocessor, e.g. a Z80A or an 8086 to design a modern computer. Electrolytic capacitor technology hasn't advanced as much as processor technology has, but it has advanced quite a bit.
                  PeteS in CA

                  Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
                  ****************************
                  To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
                  ****************************

                  Comment


                    #10
                    Re: Which capacitor type for which recapping job?

                    I was worried about having to recap again in a couple of years if I used the "short life" caps (Panasonic PC series), which I don't want to do.
                    Thinking about it though, the environment in a PSU is much harsher (temperature, ripple) than compared to say, a motherboard, so maybe the "short life" caps on the motherboard will even out the the "long life" PSU caps?

                    I see that Panasonic FM caps have a lifetime rating of 4000-7000 hours (compared to 3000-5000 of the FC series). They're both described as "low impedance". Are they interchangeable? In that case I'd opt for the longer life FM series.

                    Comment


                      #11
                      Re: Which capacitor type for which recapping job?

                      Originally posted by accent View Post
                      I was worried about having to recap again in a couple of years if I used the "short life" caps (Panasonic PC series)
                      I meant the FC-series of course

                      Comment


                        #12
                        Re: Which capacitor type for which recapping job?

                        Originally posted by accent View Post
                        I see that Panasonic FM caps have a lifetime rating of 4000-7000 hours (compared to 3000-5000 of the FC series). They're both described as "low impedance". Are they interchangeable? In that case I'd opt for the longer life FM series.
                        No, too low ESR
                        Read what I've written earlier:
                        Originally posted by me
                        FM is something you can use if you want to replace smaller Nippon Chemicon KZG. So they are for 'modern' Motherboards (early-late 2000s).
                        So if you want to replace a capacitor in a Motherboard VRM of Socket A (and later) or S478 or later, they are indeed an option and a replacement for ultra low ESR types. Sometimes, not always. I've looked at 820uF/6,3V AFAIR, those are equal or better than Nippon CHemicon KZG or maybe Panasonic FJ.
                        For you it's not something you want to use due to low ESR.
                        The smaller Panasonic FM are equal to ultra low ESR types (though a bit bigger).

                        Not something you'd want for things of the 80s and 90s....

                        Comment


                          #13
                          Re: Which capacitor type for which recapping job?

                          Originally posted by accent View Post
                          I was worried about having to recap again in a couple of years if I used the "short life" caps (Panasonic PC series), which I don't want to do.
                          Thinking about it though, the environment in a PSU is much harsher (temperature, ripple) than compared to say, a motherboard, so maybe the "short life" caps on the motherboard will even out the the "long life" PSU caps?
                          You can't generalize this way, what is harsher is going to depend on the design of the circuit.
                          A (very) poorly designed PSU could indeed put allot of stress on it's capacitors.
                          But so would a poorly designed VRM for a processor, having for example too few phases or too low switching frequency to keep up with the current demand of the CPU.
                          Consequently a poorly designed PSU that puts allot of stress on it's caps is also going to have more ripple on it's outputs: thus the CPU VRM has to work harder to compensate.

                          Originally posted by accent View Post
                          I see that Panasonic FM caps have a lifetime rating of 4000-7000 hours (compared to 3000-5000 of the FC series). They're both described as "low impedance". Are they interchangeable? In that case I'd opt for the longer life FM series.
                          Continuing my reply from above because it fits well here, no, you can not use FM and FC interchangeably, they are very far apart.
                          At the top of the FM PDF for you see this: "Low impedance (40 % to 70 % less than FC Series)"
                          Code:
                            uF  Size Ripp ESR  Endur
                          FM: 2200 10 25 2470 0.018 5000
                          FC: 2200 10 25 1440 0.045 3000
                          Notice how the ripple rating is almost double, and ESR is less than half for an equivalent 2200uF 6.3v capacitor from the respective datasheet.
                          This is a significant difference, for example if you found a PSU which had originally FC caps and you put in FM there would be problems.

                          Also please understand that the endurance rating is only one variable in the lifetime calculation.
                          I.e. the FC cap will survive for 3000 hours at 105°C with a ripple current of 1440mA.
                          But if you don't expose the cap to that much ripple it will live much longer.
                          And likewise if you reduce the temperature it will live much longer.
                          Last edited by Per Hansson; 08-04-2017, 05:08 AM.
                          "The one who says it cannot be done should never interrupt the one who is doing it."

                          Comment


                            #14
                            Re: Which capacitor type for which recapping job?

                            While the days of the hobbyist electronics stores are largely gone in the US, hobbyists of the 1980s and earlier still had to understand electronic circuits to a reasonable degree. Otherwise everything they built ended up being a "light dimmer" (old joke from a 1970s "Popular Electronics" magazine). The same is true today. A capacitor is not a capacitor is not a capacitor. You have to understand what kind of circuit you're dealing with, and you need to understand what kind of component you're dealing with.

                            For example, using a high ESR cap in a PSU output circuit or VRM output circuit will cause erratic operation by the MB and possibly cause extra stress elsewhere on the MB. The parts will also dry out quickly or vent, failing entirely. Using a PSU cap whose impedance is too low will cause problems in the PSU regulator circuit. All those hundreds or thousands of components work together, and a wrong type of component in one place can cause problems elsewhere on the MB or in the PSU.

                            You don't need to be a design engineer, but you need some understanding of what you are working with.
                            PeteS in CA

                            Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
                            ****************************
                            To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
                            ****************************

                            Comment


                              #15
                              Re: Which capacitor type for which recapping job?

                              I see (from the Panasonic datasheets I've downloaded) that the ESR value differs according to the capacitor value (uF), but was there an approximate ESR-value range of 80s/90s capacitors, so I could use that to look into which current (and available to me) capacitors I should get as replacements?

                              About lifetime expectancy: I understand I've over-emphasized this. What are "acceptable" lifetime ratings when looking at datasheets if I want quality brand capacitors and don't want to recap every few years?

                              Comment


                                #16
                                Re: Which capacitor type for which recapping job?

                                Originally posted by accent View Post
                                I see (from the Panasonic datasheets I've downloaded) that the ESR value differs according to the capacitor value (uF), but was there an approximate ESR-value range of 80s/90s capacitors, so I could use that to look into which current (and available to me) capacitors I should get as replacements?
                                I just download the datasheet of whatever is installed and check.
                                No reason to not do it properly

                                Originally posted by accent View Post
                                About lifetime expectancy: I understand I've over-emphasized this. What are "acceptable" lifetime ratings when looking at datasheets if I want quality brand capacitors and don't want to recap every few years?
                                Honestly the quality brands when rated to 2000h are fine.
                                Unless your equipment is running at something like 70°C or being exposed to excessive ripple (i.e. being designed improperly).
                                The Chinese brands also offer caps with the same ratings, their problem is in consistency.
                                One batch may make 2000h, the next fails in cold storage after the same number, you get the idea...

                                EDIT: Here is a good example where a cap rated for more than 105°C or 2000h would be useful:
                                https://www.badcaps.net/forum/showthread.php?t=21932
                                Last edited by Per Hansson; 08-07-2017, 09:17 AM.
                                "The one who says it cannot be done should never interrupt the one who is doing it."

                                Comment


                                  #17
                                  Re: Which capacitor type for which recapping job?

                                  The best available in the 90s is what we today consider low-ESR, intended for SMPS. Ultra-low ESR caps are almost phased out so that should not be a concern, do not use polymers. Some of the todays low-ESR series may be somewhat on the lower side for such old devices, on the other hand they usually had wider tolerances.

                                  Anyway, check my stock, may find some good stuff there I've just crossed 50000 pcs on-stock with the latest small KMG models…and more are constantly on order being manufactured.
                                  Last edited by Behemot; 08-12-2017, 03:59 AM.
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