Duelund cast Pio Hybrid Copper/Silver or Rs series with Silver Bypass PIO

The magic of the Cast caps is undoubtedly in the oil. I’ve used 600v Duelund Cast caps in an amp and I know the beautiful sound they convey until the oil leaks.

Oil leaks is one issue. What about the shelf life of the oil? Does oil degrade over time? Does the Duelund magic deteriorate over time?

V-Cap CuTF and Jupiter Copper caps won’t have those issues and are my preferred caps to use.

Excellent point!  I am with you on this, longevity might be the Biggest issues for the Duelund caps or any other caps that has the oil impregnated in them.   

No worries on the oil. I am not aware of any such issues in real life usage. Oil impregnated caps have been sold for decades.  This would be especially true for crossover usage where there are no heat issues to worry about. 

There are 2 excellent capaciyors I am currently using  in my preamp no direct voupkjng caps it us transformer coupled but has a big Mundorf Supreme 22uf 
Very respectable I added 15% ,the new Duelund Jam  using their latest using a lite tin over Copper which for sure opens up the top a bit in s paper oil, but in a Aluminum housing not quite as fleshed out as the cast but close at half the cost 
Very nice depth and instruments have a nice accurate tonal balance.
On the Dpeskrr end I gave a Huge 68uf  Clarity Csa cap  the Jupiter 2.2 ads some realism and depth  the last cap Brand new Jsntzen Alumen Z is a Aluminum foil with very very thin dialectric very smooth but fadt and detailed grest imaging 
A great match a very easy cap to like blends with most other caps. 
Priced very nice I put in a pr of 4.7uf caps  the Voxativ drivers really come alive 
A new budget favorite cap  they only go to 10uf.  Hifi collective is the only place yo buy , order the FedEx option delivered in 3 business days . 
Both Duelund Jam, and Jantzen  Alumen Z foil  caps  would be a great combo 
The Jsntzen only 100v ,for Loudspeakers. I AM ARE 630v and are tanks a 3.3uf 
85mmx 75mm and over 1 lb each.

Having my speakers upgraded, with the crossovers currently being made up:

• Tweeter Network - Jupiter Copper Caps (4 x 10µF and 2 x 1µF),
  
• Woofer Network - Jupiter VT Round Aluminium Caps (2 x 6.8µF)
  
• Main Caps being bypassed with Duelund Silver Caps (0.01µF)
  
• Resistors - PathAudio 10W
  
• 10awg hand wound Air Core Inductors
  

The crossover board is getting a wee bit tight, especially with the main Caps (they’re actually slightly bigger than a Coke can). Not quite finished yet, still need a couple of resistors for the Shunt, and then attach the ribbon wiring, but nearly there :)

https://imgur.com/a/xFRxn