Speaking of stacked film, for some reason i can't manage to get 'm higher than 23, must be a material property thing.
(there even was film/foil polycarbonate, e.g. Roederstein KC1850)
(there even was film/foil polycarbonate, e.g. Roederstein KC1850)
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MKC caps are fine sounding caps, better than MKT/MKS anyway. As far as I recall "material shortness" was the reason. One of the drawbacks of these caps were that the polycarbonate is very hygroscopic (so I was told). This problem existed in the green Siemens "open" polycarbonate caps. You probably know the silver coloured variant with MKT material. The caps you could file off to change their value and that easily lost their lead wires as they were quite fragile. Can't find a picture of them. No problem in audio applications whatsoever and if you like quality you probably will only use only dipped/sealed versions like the fine ERO MKC1832 Jacco showed. Excellent caps, I still have some in stock (10/63).
Google has the answer why production of the base material seized:
WIMA
I see we both shopped at the same store in Vlaardingen many moons ago, Jacco !
Google has the answer why production of the base material seized:
WIMA
I see we both shopped at the same store in Vlaardingen many moons ago, Jacco !
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They still make film from Makrolon, but not using methylene chloride solvent casting for biax. Most is extrusion cast.
There's still no-one making COC capacitor film, a real pity given the excellent mix of dielectric properties, good thermal resistance (HDT of 130°C) and high tensile strength (read: tight winding without tearing).
There's still no-one making COC capacitor film, a real pity given the excellent mix of dielectric properties, good thermal resistance (HDT of 130°C) and high tensile strength (read: tight winding without tearing).
Tight enough to avoid microphonics. Much more common with Teflon, paper, and "handmade" caps than with nice, factory-wound biax polypropylene.
I think "hand-made" or "hand-wound" is a misnomer when applied to limited production capacitors. "Wound manually" on non-automated machinery would be a better description.
John
John
That's the reason for the scare quotes. Point remains that using a hand-cranked machine is NOT the way to get a nice, tight winding.
I've read a few posts over at audio asylum sounding the praises of PPS caps - however there is not a particular brand/make that people recommend.
What would be a suitable 1uF PPS cap for dc blocking in the signal path at the output of a tube preamp stage?
What would be a suitable 1uF PPS cap for dc blocking in the signal path at the output of a tube preamp stage?
haha why not? interesting you should mention that....I have just changed wima mkp4 to vishay mkp1839 and notice no difference!
Actually, I tried 1.5uf 63V PPS EVOX Rifa SMR caps as DC blockers, and found them to be good and competent, but not in any way really exciting to listen to. To their credit, they sounded the same from the moment they were installed as they did a month later. Take this to mean they don't "run in". They sound the same, which makes this the only cap I have heard that is like this. So If you want a subjective rating from me, as a coupling cap, I'd say they are a mid range cap. Certainly better than some, and better than an electrolytic, but not as exciting or extended sounding as some MKP caps.
You could use far worse or better.
PPS is polyphenylene sulfide -- superior to polycarbonate in terms of dissipation factor as this article tells:
PPS stands in for polycarbonate in film capacitors - Electronic Products
PPS stands in for polycarbonate in film capacitors - Electronic Products
I completely agree, they sound somewhat 'gray'...
On the contrary polycarbonates sounds very good and have a very nice timbre but, IMHO, a film/foil (not metallized) polypropilene is way better...
DF is important but each dielectric seems to have a distinct timbric signature, some are balanced, others not...
that is because both of them are polypropylenes...i'd be disappointed id you noticed a difference.....😀
Have a look at the datasheet...this one is only an example...Read carefully lower parts, but NOTE: Depending on manufacturer,NOT all vendors produce AC rated caps have sim ratings for DC....it varies from one to the other, and check product datasheets.
Not my responsibility if one gets injured and premises burns down !
Richy
What's the problem? 275VAC is 778 Volts p-p. Nothing inconsistent here.
G²
Sounds like it may be worthwhile trying them (a neutral sound, is IMHO, much better than a coloured sound when using tube gear...it allows one to hear the differences between tubes without worrying about the capacitors in the signal path too much).
How about these:
PANASONIC|ECQE4105JF|CAPACITOR, FILM, 400V, 1UF | element14 Australia
Farnell lists them as PPS in the description, however the datasheet:
http://www.farnell.com/datasheets/425842.pdf
Shows them to be "metallized polyester" - surely that is not the same as PPS?
How about these:
PANASONIC|ECQE4105JF|CAPACITOR, FILM, 400V, 1UF | element14 Australia
Farnell lists them as PPS in the description, however the datasheet:
http://www.farnell.com/datasheets/425842.pdf
Shows them to be "metallized polyester" - surely that is not the same as PPS?
Definitely not the same. Farnell appears to only have surface mount PPS caps (Panasonic ECHU Series) which are rated to only 50V. They are described as "Plastic Film".
R.S have thru' hole Panasonic ECHS Series but only to 100V rated.
The ones I have used in the past are these Evox Rifa SMR Series
KEMET Evox Rifa SMR High Temperature Film Capacitors - TTI Inc.
I did buy them from R.S. but it seems I must have been one of the few as they have been dropped from their cattle dog.
Cheers,
Ian
R.S have thru' hole Panasonic ECHS Series but only to 100V rated.
The ones I have used in the past are these Evox Rifa SMR Series
KEMET Evox Rifa SMR High Temperature Film Capacitors - TTI Inc.
I did buy them from R.S. but it seems I must have been one of the few as they have been dropped from their cattle dog.
Cheers,
Ian
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