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Combining caps to get a value - is there a difference?

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  • #16
    Get falling down drunk and assemble the XO's and listen to them in your car in the garage with the windows down and the stereo playing in the laundry room?

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    • #17
      No, No, NO! I've got it!

      You wrap all of your capacitors in painter's tape, put them in a box and shake them up and then randomly select an equal number from the the box (without peeking under the tape) and assemble the XO's with them.

      Well, that won't really work because then all you have left to do the blind comparison too is a bunch of randomly mixed up capacitors . . .

      I'll be back, I'm not done with this yet . . .

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      • #18
        Seriously, if somebody tries a blind test, measure your capacitors carefully. Electrolytics are often 20% tolerance. Obviously if one group of capacitors has a bunch more or less capacitance than another, they won't necessarily sound the same.
        Francis

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        • #19
          Originally posted by andykriech View Post
          Well, I am not sure that I would know how to blind XO change testing to myself...how does one do that?
          andy
          I have a love/hate thing with blind testing.

          Several small things I have done/changed over the years gave me that "Good feeling" and reassurance things were better for sure.
          But after a while, I read a lot, decided to blind test on a few things that were easy to change back and forth (relatively).

          My concern, just about everything I had changed, I was not able to tell for sure if it did or did not make a difference, minus the really old electrolytics that were easily discerned.

          For my comparisons blind, resorted to coercing a youngish female family member (teen) who had no cares about this stuff, with the incentive of being rewarded, to help.

          Wifes seem to have no interest. Guy friends ask WHY?? So not easy to find someone to assist.

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          • #20
            We've all been here...
            Attached Files
            Francis

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            • #21
              ^ HA! No doubt.. I am absolutely a 95% guy. I figure it is easy to get to 90%, takes moderate effort to get to 95%, and herculean effort after that. I fully embrace the concept of diminishing return and am happy to live with my 95%.

              ...at least right now. If I keep hanging around here though..

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              • #22
                Originally posted by Dukk View Post
                ^ HA! No doubt.. I am absolutely a 95% guy. I figure it is easy to get to 90%, takes moderate effort to get to 95%, and herculean effort after that. I fully embrace the concept of diminishing return and am happy to live with my 95%.

                ...at least right now. If I keep hanging around here though..
                I'd say resistance is futile, but actually it's darned useful sometimes.
                Francis

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                • #23
                  I got tired of paying big bucks for audiophile caps and search ebay for high voltage SPRAGUE, CDE, Bishop, and Relcap metalized polypropylenes. I have pretty good luck with caps with over 600 DC volt ratings. Don’t use oval shaped caps since they have lousy winding tension that leads to microphonics. Most of the film and foils caps I have tried sound detailed but hard and eventually fatiguing. The exception being high voltage 0.047 and smaller bypass caps. I think that the higher voltage caps thicker dielectric may allow for higher winding tension and less microphonics. One of the worst caps I have tried was a a multi cap film and foil oval shaped cap. Do not try to evaluate a cap right after you solder it. They sound better after playing over night with a broad band noise signal over night. I use thunder storm or fire recordings on you tube on the completed speaker.

                  The Cornell Dubilier 940C / 0,01uF / 3000VDC bypass caps recommended by Tony Gee by do sound good on tweeter cross overs as does the same series cap in the 2000VDC rating. Some his rankings of low and medium priced caps are not too different from my experience as well.

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                  • #24
                    Andy (OP) - you might be able to shave cost by using back to back polarized caps for the larger values, and the ability to get the voltage rating doubled by using the pair in series.
                    I have recently done this, and would up with a 450uF/500VDC electrolytic cap pairs for about $20 for the set of 4 parts.

                    Later,
                    Wolf
                    "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                    "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                    "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                    "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                    *InDIYana event website*

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                    http://techtalk.parts-express.com/blog.php?u=4102

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                    • andykriech
                      andykriech commented
                      Editing a comment
                      Hi Wolf, by "back to back" do you mean in series? So, 2 500uF/100v caps in series (give 250uF & 200v) in parallel with another 2 250uF/200v pair would give 500uF and an increased votage rating?

                    • Wolf
                      Wolf commented
                      Editing a comment
                      Yes- tie the neg or pos terminals, and use the other 2 to connect the circuit. Yes- it takes 4x polarized caps to get the same capacitance at twice the voltage rating.

                  • #25
                    Everytime this discussion comes up I refer people to Frank VanAlstine's Audio Basics. Frank was a Dynaco engineer, then went into business for himself, so he knows his stuff He published a newsletter which I subscribed to, in part because it could be hysterically funny. "Magic caps" comes up repeatedly in there, Therefore I can't point to specific issue, but it is downloadable for free on his website, AVAhifi.com, I think under resources tab. He takes on all sorts of audio myths and misunderstandings in there. Good reading.

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                    • #26
                      Another bargain in large value caps is Motor Run capacitors. They're usually polypropylene film, and are available in values up to at least 120uF (that I know of) through industrial suppliers on eBay. Check the datasheet for any cap you get, but so far all the Run rated caps I've seen are polypropylene. Motor Start caps on the other hand are electrolytic.Prices are around $15 for the ones I've bought.
                      Francis

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                      • andykriech
                        andykriech commented
                        Editing a comment
                        Thanks Francis, I wasn't aware of this type of cap. Will check them out.

                    • #27
                      Quick update, making progress on the Black Boxes boxes, almost ready for assembly. Having some fun making do with only what I have on-hand...
                      Will be researching some of the great suggestions provided here for the final XOs.

                      Really appreciate everyone's help and suggestions.
                      Stay safe.
                      Andy

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