Boutique caps in oil... reliable?

      Back when they were a couple hundred bucks each; I replaced the four coupling caps, in my tubed monoblocks, with Duelund's .22uF 630V, CAST PIO, pure Cu foil's.

      Within six months I noticed a tiny puddle under one of the amps and called Parts Connexion, who instructed me to return all four.

      Apparently: Duelund had a bad run and was replacing any parts from that batch gratis.

      Returned the baddies and received the new caps within the same week.

      I was absolutely happy with their caps and issue resolution.

                                It's hard to be perfect all the time! 

     Some may remember the Black Gate caps from Rubycon.   MAN, how I miss those babies!

      Anyway: here's a funny, cap-failure flashback, related to Rubycon (an EXCELLENT manufacturer), their non-solid, aluminum electrolytics and a major industrial espionage fail:

     btw: It's been a few years (at least eight) since those Duelunds were replaced.

                     Still: wonderful reproduction/no need for Pampers.

@charles1dad -

What makes the Blackgate capacitors special ?

     I can state, as a certainty, when they were used to upgrade existing electrolytics: the component's performance was enhanced.  In my experience: very few ever disputed that.

     What MADE them so special would be more apropos, as they were discontinued about 15-20 years ago, much to my dismay.    When that happened: the remaining stocks were quickly snatched up.

     Far as what made them different/better/special: something about the use of graphite impregnated paper as the cathode and the oxide that formed on the aluminum foil (anode) becoming the dielectric.    Probably why they took forever to settle into their ultimate, wonderful presentation.    At least: that's how it seemed, whenever used in an audio signal path.

     The catalog of the Black Gates was extensive.    Just about everything/anything in electrolytics a POOGEr (ala Walt Jung) could ever need/want, to enhance their listening experience.

      First thing I searched for, when I bought my Cary monoblocks, was an appropriate octet of their WKz caps, that were dynamite in tube amp power supplies.

                              UNOBTAINIUM/BUMMER!

@charles1dad -

     When @roxy54 mentioned Audio Note, it rang a bell in my empty head and I did a little search.

     Mr Qvortrup also started using Black Gates back in the 80's

     Beside that tidbit: the following is an interesting article:

           https://www.audionote.in/the-black-gate-story

     As I mentioned: BGs take a LOOONG time to reach their prime, so- be patient when you get your new DAC.   

                                    btw: Thanks for the props!     

                It's good to know, I'm helping someone in their quest.

                                          Happy listening!