You're right about the price Michael. Since receiving some rave reviews, including on this site, prices have raised to incredible heights. A pity as the Duelunds no doubt are fine caps but IMO and IME the extra quality compared to that of other fine PIO copperfoil caps (and OTHER measures than caps, inductors and wire that can be taken in an audiosystem!!!) doesn't justify the very big difference in retailprice.
I don't know the Cu V-cap, however I've tested the tinfoil V-caps a few years ago and IMO they didn't held up with the standard Jensen PIO copperfoil cap. The difference was big. The tinfoils are fast and detailed but compared to the PIO copperfoils they sound "thin" / less musical. And this judgement came after at least 500 hours of playing in time.
I collected three early cost-no-object early Siltech hybrid poweramps that I've upgraded by a Dutch engineer called Peter van Willenswaard. He used to work for AudioNote UK and now has his own company Audiomagic. Peter is a BIG name with tubes in the Netherlands/Europe. His DAC for instance is a killer. Peter built up a lot of experience with upgrading AN DACs. So much that he decided to design his own DAC. This DAC, though costing about 1/20th of the most expensive AN DAC, performs in the same league as that AN DAC. No wonder it won the first price at a shoot out of the European Triode Festival some years ago.
I have asked Peter to test the tinfoil teflon V-Caps and the Cast Cu-foil Duelunds as I wanted to replace the old coupling caps in my hybrid poweramps by better ones, and these two companies received rave reviews a couple of years ago. A befriended audiocompany in the Netherlands ordered the Cast Cu-foil Duelunds from Frederik as the company was very interested in Peters opinion on the Duelund caps. The V Caps I ordered in the USA.
Peter put them to test in his own design preamp (position of the caps: coupling caps) and audiosystem. The judgement about the V-caps was quickly made. And even after 500 hours, its sound was still not okay in our experience. This became very painfully clear after replacing the V Caps by Jensen Cu-foils: the immediate improvement of the sound with the Jensens installed was SO big!
The Jensens went out and the Cast Duelunds were connected. A long time of playing in followed. Gradually, very gradually its sound got better and better until it performed a bit better than the standard Jensen PIO Copperfoil caps. After a few hundred hours the Duelunds were taken out and returned to the audiocompany...
They made place for the Jensen PIO Cu-foils in paper tube. The paper tube Jensens sounded already from the start significantly better (more detailed) than the standard Jensen PIO Cu foils... So my choice in the end was the paper tube Jensen.
I must admit that my Cast Duelunds belonged to the first badges produced by Duelund as in my first emails to Duelund, Frederik responded that the high voltage Cast caps didn't exist yet, but that they were working on it. Maybe in the later badges other dimensions/design and materials were used?
I'm very curious to your experiences with the Cufoil V-cap, especially how it performs compaired to its tinfoil sister or brother.
Kees