MKP 'Audiophiler' Metallized Polypropylene Caps

[dorrisant]

Just wondering what the opinions on these are...

http://www.tubesandmore.com/products/C-MKP

Has anyone used these? If so where? In particular, any opinions on using them as cathode bypass caps? I know they are huge, but do the pros outweigh the cons?

Closing eyes and preparing for a $#!+storm,

Tony

[Leo_Gnardo]

You'll get no such @&$%+ storm from me. Yes they sell awful cheap for film caps but I've used 'em in presence controls, so far so good. Same for rudimentary crossovers, mostly blocking low freqs to smaller speakers as in some old Gibson and Sano amps where there's a 12" or 15" plus an 8". 400V rating means unlikely to fail in either application. Yes they're physically way big for cathode bypasses but I bet they'd work just fine.

[V2]

they were used in the 10-watt Phaez Daisycutter kit amp:
https://www.youtube.com/watch?v=qumL2poI7dQ

Sounded good in that amp (I built one).

[VacuumVoodoo]

Offered range of capacitance values suggests these are primarily for loudspeaker cross over networks.

[dorrisant]

Thanks for the opinions guys...

I think I will order one of each and see how they fit and sound.

Tony

[Tone Lover]

The red looks cool to bad they were not 630v. I would use them instead of the Solens for the power supply in fenderish type designs I do. I hate electrolytics if I can get away from them.
Bill

[Jerryz1963]

I had this article on caps and I lost it

This is really a confusing topic. According to one article which seemed authoritative, PIO aint so great 'cause they are leaky. Then I find another that shows actual screen shots of tests and PIO bests the bunch!

First article states polypropylene (Teflon) are best, followed by polystyrene. Second article also states they are close, but reverses them, saying polystyrene is the better of the two.

I note that affordable polypropylene are hard to find and I usually settle for polystyrene. I am curious to try PIO and wonder if the first article is correct about them being "leaky." Maybe he was referring to vintage?
If I find the article with the screen shots, if there is any interest, I'll post it.

Both articles involved actual testing (not just ears, but by taking measurements). I found plenty where it was just "ear" testing and I'm extremely skeptical of same.

[Leo_Gnardo]

First article states polypropylene (Teflon) are best, followed by polystyrene. Second article also states they are close, but reverses them, saying polystyrene is the better of the two.

I note that affordable polypropylene are hard to find and I usually settle for polystyrene. I am curious to try PIO and wonder if the first article is correct about them being "leaky." Maybe he was referring to vintage?
If I find the article with the screen shots, if there is any interest, I'll post it.

Teflon is NOT polypropylene. Polypropylene hard to find? Yes I suppose. Mouser only has a couple pages of them... metallized (MPP) and not. Digikey too. And Antique has a good choice too. Plus several varieties of mylar film: my faves Mallory 150. Mojo has their "Dijon's", and a couple more expensive varieties from Sozo. PIO - Mojo now has their "imported from Brazil" PIO's brand new not leaky not expensive like Vitamin Q also not likely to contain Polychlorinated Biphenyl (PCB). It's all there, if you look. Polystyrene are good but usually don't have hi voltage ratings worthy of use with tube circuits. Where do you get yours?

Last couple of years the main source for teflon caps has been Russia - there are a couple of vendors with stocks of mil surplus but numbers are running low and prices going up lately. Some folks run 200V rated caps above 500V and claim they're not breaking down. If you like to play Russian roulette scan ebay and good luck with that.

[martin manning]

Vishay 715 and 716 Orange Drops are PP.

[Jerryz1963]

I was confused by that Teflon business. It seems there is more contradictory than confirmatory info regarding caps, just makes it frustrating trying to learn anything. Thank you for clearing that up. I just settled for plastic dielectric, metal film. I would like to try some PIO if they aren't priced into the stratosphere. I usually get mine from DigiKey and Mouser, I occasionally get some from ebay - since ebay revised their business model that's gotten much worse - you can't trust anyone, the ratings are meaningless.

I have used one vendor, "Just Radios" They send along a biz card with prices and values of caps on the back. All 630 volt caps. 2 uf to 0.0005 uf.
They are in Canada. If you are having trouble finding an obscure value, worth a look

So you like Mylar film? One of the articles (I think, can't remember for sure) trashed Mylar. The last one I read mentioned polycarbonate which fared well in the tests, and I don't recall running across that dielectric much, if at all.

[rp]

According to one article which seemed authoritative, PIO aint so great 'cause they are leaky.

You only see PIO in vintage test equipment, things like Tektronix scopes and old lab equipment, that big heavy grey metal stuff that no one knows what it ever did. Stuff that had to be stable and reliable and durable and was very expensive in it's day. Must say something about the quality of PIO. You never, at least I have never ever, seen then in vintage MI equipment. Sometimes in vintage hifi but even there it is very rare. Until the boutique DIY era began in the mid 80s no one thought PIOs were worth putting in guitar amps. Now that we have flaky crap from Brazil everyone wants them

[davent]

Justradios has 630v polystyrenes from 10p to 10n.

http://www.justradios.com/cart.html

[Leo_Gnardo]

So you like Mylar film? One of the articles (I think, can't remember for sure) trashed Mylar.

And what were they trying to sell? Usually that kind of review comes from someone trying to flog their own whatever. Hey it's the internet, everybody has a friend for a minute then not, and nobody knows you're a dog.

[cbass]

The caps that sound best are ones you can't buy anymore

[rp]

So you like Mylar film? One of the articles (I think, can't remember for sure) trashed Mylar.

And what were they trying to sell? Usually that kind of review comes from someone trying to flog their own whatever. Hey it's the internet, everybody has a friend for a minute then not, and nobody knows you're a dog.

and were they trashing them in MI or Hifi, most the the diligent cap shootouts out there are in the hifi realm. I can see 10 cent green chick-lets underwhelming in hifi, but on a diy vintage pedal forum they might be the shizz.