Boutique caps in oil... reliable?

Erik,

As you mentioned wax, no issues with Jupiter HT.

Running now for 9 years and are close to signal tubes.

No experience with oils.

      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.

@rodman99999 btw: It's been a few years (at least eight) since those Duelunds were replaced.

                     Still: wonderful reproduction/no need for Pampers

Understood. I’ve had the Duelund CAST PIO copper foil capacitors in my speakers and DAC for about 10 years and have experienced zero problems with them. They sound splendid!

@rodman99999 

What makes the Blackgate capacitors special ? I know that they are held in high esteem by many. I lack any experience with them.

Charles

Check out this variety of caps from Jupiter Condenser.

For a vintage sound paper-in-oil capacitor, you might look at their VitaminQ or Comet caps.  According to Jupiter:

These capacitors utilize the same polymerized impregnation fluid developed by Sprague in the 1940s.  Hermetically Sealed and processed under a deep vacuum for several days.  Hermetic sealing keeps oil from leaking out and provides protection from ingress of moisture to ensure long life.  Glass to metal end seals are soldered into tin-plated brass tubes to form leak-tight joints.  Jupiter Aluminum Foil Vitamin-Q capacitors are built to Mil-Spec standards yet developed and refined for beautiful sound.

I have had their Copper Foil Paper & Wax Capacitors 600V in a preamp for around the past 8 years with no problems.

However, I once owned a BAT VK-51SE that leaked out of one of the Bat-Packs.