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United Chemi-Con "ASF"-- Is this a fake?

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    #1

    United Chemi-Con "ASF"-- Is this a fake?

    Hi,

    Yes, I'm in the middle of a few projects right now. My biggest one is an amplifier. I bought a kit off eBay for a subwoofer preamp. It came today. Origin: China.

    When I opened it, it has some unfamiliar caps. They are United Chemi-Con "ASF". I've never seen an "ASF" in my life, so I did some research. The only thing that turned up is that it is an audio grade cap, regarded pretty well by the audio comunity. I'm a bit dissapointed they are only 85*C, but this seems typical among "audio caps".

    So my first question. Does anyone have a datasheet for the ASF? Secondly, do these look real? It was from a legitimate China based eBayer. I don't think they are fake, but you never know, especially with these caps being "rare" and such.

    Pictures are attached.

    Thanks.
    Attached Files
    Last edited by TheLaw; 04-04-2011, 07:47 PM.
    Tags: None
    #2
    Re: United Chemi-Con "ASF"-- Is this a fake?

    They look real to me. No luck finding an ASF datasheet. Perhaps it's one they market to OEMs only.

    Comment

      #3
      Re: United Chemi-Con "ASF"-- Is this a fake?

      Ah. There's a chance.

      I think they look real too...

      Thanks.

      Comment

        #4
        Re: United Chemi-Con "ASF"-- Is this a fake?

        Chemicon ASF, AWF and a few others are high-end audio-grade caps that were probably discontinued in the 90s or early '00s. The only source seems to be NOS lots on EBay which for some reason are mostly in China and SE Asia - may be surplus lots from audio equipment manufacturers.

        Virtually all the high-end audio-grade caps are 85c, moderately high ESR, and not very high ripple current. They're optimised for higher linearity, lower Dielectric Absorption and comparatively lower Dissipation Factor, which are more useful properties for Linear Circuits. They're also priced about 10x-100x the price of a computer-grade low ESR cap with similar ratings. Check out the price difference between a Panasonic FJ (computer-grade) and a Panasonic Pureism PX or PXL (high-end audio-grade). Even better, check out a Rubycon ZL vs. a Rubycon Black Gate WKZ - the price difference will be about 1000x.

        Comment

          #5
          Re: United Chemi-Con "ASF"-- Is this a fake?

          The date code on that suggests September 2009...



          I'm not sure what their pre-2000 date codes looked like, and that document doesn't help.

          Comment

            #6
            Re: United Chemi-Con "ASF"-- Is this a fake?

            Originally posted by linuxguru View Post
            Chemicon ASF, AWF and a few others are high-end audio-grade caps that were probably discontinued in the 90s or early '00s. The only source seems to be NOS lots on EBay which for some reason are mostly in China and SE Asia - may be surplus lots from audio equipment manufacturers.

            Virtually all the high-end audio-grade caps are 85c, moderately high ESR, and not very high ripple current. They're optimised for higher linearity, lower Dielectric Absorption and comparatively lower Dissipation Factor, which are more useful properties for Linear Circuits. They're also priced about 10x-100x the price of a computer-grade low ESR cap with similar ratings. Check out the price difference between a Panasonic FJ (computer-grade) and a Panasonic Pureism PX or PXL (high-end audio-grade). Even better, check out a Rubycon ZL vs. a Rubycon Black Gate WKZ - the price difference will be about 1000x.

            I didn't choose to buy them. I think "audio quality" caps are complete B$.

            Comment

              #7
              Re: United Chemi-Con "ASF"-- Is this a fake?

              sell them on ebay for a profit and buy "normal" caps for 1/8th the price of those audiophool's wet dreams

              Comment

                #8
                Re: United Chemi-Con "ASF"-- Is this a fake?

                I would sell them if I had more, but with only two, I can't sell them for too much...Maybe $3-4. So I don't really care.

                Panasonic FM here we go! =D

                Comment

                  #9
                  Re: United Chemi-Con "ASF"-- Is this a fake?

                  Well there's no FM in 4700uF 25V, so I thought I'd do FC..which are $2.50 a piece, $5 for 2...I think I'll just use what they gave me.

                  They're good caps. Not high temperature or the best for ripple current etc, but mind you , this is going on a preamp board, nothing rediculous. If some spending money gets freed up from the budget, I'll consider FCs, but until then, these "ASFs" don't look that bad.

                  They are 18mm x 35mm which is actually pretty large for their specs, so they might not be all that bad in the end. Datasheet would still help. =D

                  Comment

                    #10
                    Re: United Chemi-Con "ASF"-- Is this a fake?

                    Date code appears to be Feb 1999.
                    Might wanna research "Reforming Capacitors".
                    .
                    Mann-Made Global Warming.
                    - We should be more concerned about the Intellectual Climate.
                    -
                    Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
                    - Dr Seuss
                    -
                    You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
                    -

                    Comment

                      #11
                      Re: United Chemi-Con "ASF"-- Is this a fake?

                      Found ASF in UCC catalog from year 2000. - In the Japanese catalog only...
                      .
                      Also found specs but it's not in PDF and not in English.
                      .
                      4700uF/25 shows Ripple as 1900 -> at 120Hz.
                      Low ESR caps are rated at 100kHz.
                      .
                      Those aren't just GP caps they are lower grade GP caps.
                      [Grade and Quality are not the same thing....]
                      .
                      .
                      Mann-Made Global Warming.
                      - We should be more concerned about the Intellectual Climate.
                      -
                      Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
                      - Dr Seuss
                      -
                      You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
                      -

                      Comment

                        #12
                        Re: United Chemi-Con "ASF"-- Is this a fake?

                        Wow thanks. Uh in that case, though reforming might work...You've kind of convinced me to just buy some decent low-ESRs. The board uses a split supply, so each one is responsible for filtering a + rail, and a - rail. Since their job is to filter really noisy DC, I don't see what the purpose of using a cap like this would be...I seriously cannot hear the difference.

                        Hell, I had some Chengs and CapXons in a Logitech 2.1. Admitadly, the caps were pretty low-scale, but after recapping them in "audio quality Nichicon" (FG, FZ, FW, KW), they sounded not a smidgen different to my ears. What a waste.

                        However, I do believe in good quality caps, but not necessarily the audio-grade rubbish. Audio grade caps have a pretty crappy lifetime so I hear...What's the point?

                        The picture on the eBay listing had them down with Panasonic CE, which isn't the best either, but I think I'd prefer them to this ASF thing...I wonder what unsuspecting audiophool I can sell this to...Hmm...$10 a pop??

                        The listing if anyone was curious: http://cgi.ebay.com/Subwoofer-12HZ-4...item2eb4544250

                        Comment

                          #13
                          Re: United Chemi-Con "ASF"-- Is this a fake?

                          I should have thought to look in the Japanese page. They do have quite a few caps listed that I was unaware of, though ASF doesn't seem to be one of them...

                          Comment

                            #14
                            Re: United Chemi-Con "ASF"-- Is this a fake?

                            Originally posted by TheLaw View Post
                            The picture on the eBay listing had them down with Panasonic CE, which isn't the best either, but I think I'd prefer them to this ASF thing...
                            CE is not the series on those. NHG is. General purpose 105°C cap. not low ESR (silver markings ; low-ESR pannys usually have gold markings (except the new FR series AFAIK))



                            on a side note.. the caps in the auction pics are also 16V instead of 25
                            Last edited by Scenic; 04-05-2011, 08:25 PM.

                            Comment

                              #15
                              Re: United Chemi-Con "ASF"-- Is this a fake?

                              Originally posted by Scenic View Post
                              CE is not the series on those. NHG is. General purpose 105°C cap. not low ESR (silver markings)
                              Really? Hmmph. I thought NHG was just the prefix that Panasonic has. Like EEU-FM. I guess not.

                              Well, whatever...=D

                              Comment

                                #16
                                Re: United Chemi-Con "ASF"-- Is this a fake?

                                As far as I know, all Chemi-Con 85C electrolytics never come in a brown sleeve, but they normally come in a black sleeve, except for special purpose units such as low leakage units.
                                My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

                                Comment

                                  #17
                                  Re: United Chemi-Con "ASF"-- Is this a fake?

                                  Which would make sense I think...Actually 25V is way overkill. The input on the board is 6V-0-6V. So if each cap is getting ~8.5V after rectification, what's the point of 25V. Must have had extra stock....Maybe I should find some decent 16V then. Maybe FM comes in 4700uF 16V.

                                  Comment

                                    #18
                                    Re: United Chemi-Con "ASF"-- Is this a fake?

                                    Originally posted by japlytic View Post
                                    As far as I know, all Chemi-Con 85C electrolytics never come in a brown sleeve, but they normally come in a black sleeve, except for special purpose units such as low leakage units.
                                    I'm pretty sure these are real...but they definitely aren't common, and I don't know crap about them, though PCBONEZ has of course miraculously produced a datasheet out of thin air.

                                    Well I don't want this to turn into a 1.5 week long dicussion like last time, so I'll try not to share my entire life with you guys. =D

                                    Comment

                                      #19
                                      Re: United Chemi-Con "ASF"-- Is this a fake?

                                      They are real just an obsolete series that is no longer manufactured so the data sheet is no longer provided.

                                      ~~

                                      http://waybackmachine.org/

                                      They save random web pages for some historical purpose.
                                      Sometimes if you dig a little through their cached pages you get lucky on obsolete data sheets.

                                      This was saved Nov 16, 2000.

                                      http://replay.waybackmachine.org/200...sf/size_j.html

                                      .
                                      Mann-Made Global Warming.
                                      - We should be more concerned about the Intellectual Climate.
                                      -
                                      Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
                                      - Dr Seuss
                                      -
                                      You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
                                      -

                                      Comment

                                        #20
                                        Re: United Chemi-Con "ASF"-- Is this a fake?

                                        Originally posted by PCBONEZ View Post
                                        They are real just an obsolete series that is no longer manufactured so the data sheet is no longer provided.

                                        ~~

                                        http://waybackmachine.org/

                                        They save random web pages for some historical purpose.
                                        Sometimes if you dig a little through their cached pages you get lucky on obsolete data sheets.

                                        This was saved Nov 16, 2000.

                                        http://replay.waybackmachine.org/200...sf/size_j.html

                                        .
                                        Well that's a handy trick to keep in mind.

                                        Yeah those are pretty meh caps. I'll try something else.

                                        Comment

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