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  • #16
    On glass caps, real ones, for the record Peavey used them in some late 70's - 80's amps. Little guys that looked like diodes. They fit an unexpected amount of capacitance in a tiny package, the tradeoff being rated at low voltage. Definitely not electrolytic, I take it they were some kind of thin film technology. There were also caps in glass cylinders, film in oil, from the 1950's - early 60's. I have one, it's a work of art. About 1.5 inches long, half an inch wide cylinder. But I don't think I wanna know what kind of oil is in there - could well be polychlorinated biphenyl or some similar poison.

    Back to the program already in progress...
    This isn't the future I signed up for.

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    • #17
      Originally posted by Helmholtz View Post
      I have an assortment of Styroflex caps from the 80s (as well as databooks). Those were/are all labelled in plain pF values.
      I love polystyrene capacitors. Unfortunately, they have 3 main disadvantages. First, like you mentioned, they can be damaged at relatively low heat. Second, they are often terminated with very light gauge lead wire (but not always). Lastly, manufacture of capacitor grade polystyrene largely ceased in 2012. So, much like polycarbonate, small runs of new production rely on stores of warehouse stock.

      Plus, just between all of us,... I like the way they sound
      But you'll never get me to admit it.
      If I have a 50% chance of guessing the right answer, I guess wrong 80% of the time.

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      • #18
        Me too - LCR Components in Wales UK are a small UK manufacturer, I've been buying their 630V low pF polystyrene caps for decades, excellent spec, they're distributed by Farnell so I guess that Newark should carry them in North America.
        The 630V range have nice sturdy leads
        A company I used to work for needed a 0.33uF 50V high spec cap, LCR made a small custom batch (polycarb I think) at a very reasonable cost.
        http://www.farnell.com/datasheets/17...790.1537990594
        Last edited by pdf64; 07-26-2019, 11:26 AM.
        My band:- http://www.youtube.com/user/RedwingBand

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        • #19
          Originally posted by pdf64 View Post
          Me too - LCR Components in Wales UK are a small UK manufacturer, I've been buying their 630V low pF polystyrene caps for decades, excellent spec, they're distributed by Farnell so I guess that Newark should carry them in North America.
          The 630V range have nice sturdy leads
          A company I used to work for needed a 0.33uF 50V high spec cap, LCR made a small custom batch (polycarb I think) at a very reasonable cost.
          http://www.farnell.com/datasheets/17...790.1537990594
          Newark was acquired by Avenet recently, but It looks they still are partnered with Farnell for inventory and distribution for now.
          47-720pF @ 630V is pretty sweet. I could use those all day
          If I have a 50% chance of guessing the right answer, I guess wrong 80% of the time.

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          • #20
            Some Styroflex caps demonstrating that even large nF values were labelled with pF numbers. An additional letter specifies cap tolerance. The huge 0.1µ one is probably a prototype or a special order sample:

            Click image for larger version

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            Last edited by Helmholtz; 07-26-2019, 01:55 PM.
            - Own Opinions Only -

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            • #21
              Originally posted by Helmholtz View Post
              Some Styroflex caps demonstrating that even large nF values were labelled with pF numbers. An additional letter specifies cap tolerance. The huge 0.1µ one is probably a prototype or a special order sample:

              [ATTACH=CONFIG]54472[/ATTACH]
              Now THAT ^^^^ is my idea of a proper capacitor!!
              Logic is an organized way of going wrong with confidence

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              • #22
                I only dig this thread up because I had a question about identifying voltage rating. I have some ranging from 100pF-1000pF.

                Click image for larger version

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                Helmholtz, do you know if the markings hold true across all manufactures? Do you know what the voltage rating is on these?
                If I have a 50% chance of guessing the right answer, I guess wrong 80% of the time.

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                • #23
                  I put polystyrene caps in my headphone amp, and ironically I recently listened to this vocalist
                  Click image for larger version

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                  also Poly Styrene (RIP)
                  their best song
                  https://www.youtube.com/watch?v=xjVVhJ-INWQ
                  lots of polymers therein

                  on the caps those leads are incredibly weak, I think tinned copper

                  here's a nice breakdown of different PS caps.
                  https://www.tedss.com/LearnMore/Poly...ilm-Capacitors
                  (also a Ted)

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                  • #24
                    Originally posted by tedmich View Post
                    on the caps those leads are incredibly weak, I think tinned copper
                    Fortunately the most of the ones in I have (some in that photo) have nice heavier gauge leads than some of the other common polystyrene types. I wanna say, like, 20AWG or there abouts

                    Edit: just checked out that tedss link. Just what I was looking for
                    If I have a 50% chance of guessing the right answer, I guess wrong 80% of the time.

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                    • #25
                      Helmholtz, do you know if the markings hold true across all manufactures? Do you know what the voltage rating is on these?
                      German manufacturers used:

                      blue: 25VDC
                      yellow: 63VDC
                      red: 160VDC
                      green: 250VDC
                      brown: 400VDC
                      black: 630VDC
                      orange: 1000VDC

                      Don't know about other countries.
                      - Own Opinions Only -

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