Anyone have experience with these? I know the consensus around here is that silver is' bad' and kills the music, but do you believe in different types/quality of silver? Just like we know there are different types of copper which ultimately do sound different.
Anyways, these CAST Ag seem to be Jimmy Auw's (avid diy tweaker to the max! respect!!) favorite cap to run in his Aikido preamp. He has tried most caps available in the market on his system and still says his reference are these CAST Ag!
http://www.audiohum.es/DIY-components/Electronic-components/Film-capacitors/Due/Duelund-CAST-Silver-Foil-Capacitor
http://jimmyauw.com/2010/08/16/battle-of-three-capacitors/#more-1529 (AudioNote copper mylar VS Jensen copper paper tube VS Jensen copper with copper tube)
Brief conclusion:
Audio Note comes back with its new Mylar-in-Oil design. Should have better reliability because of its new design and also have better high frequency extension. But I think Audio Note still emphasizes on the midrange band, as if we are talking a full range speaker here. It’s your call, not a matter of right or wrong. At US$ 55 each for 0.47 uF, the price is quite a bargain.
Jensen maintains the old Paper-in-Oil design, but they are offering 4 type of chassis (Aluminum, Paper, Copper, and Ceramic). The overall vocal is quite sweet, but with added dynamic and high frequency extension. Surprisingly, the Copper Tube provides significant improvement. The Copper Tube has even better high frequency, separation, and resolution, although with a small trade-off on the midrange side. While the Paper Tube could be an all-round solution, sweet vocal, but with extra high frequency compared with the Audio Note.
As comparison, I would prefer Copper Tube on 300B, Paper Tube on EL34, and Audio Note on KT88 Push Pull or perhaps 2A3.
Sorry if my review sounds that I don’t really like all those three capacitors above. They are very good to excellent capacitors, really! But since my daily life is with the Duelund CAST Ag, so it’s very hard for me to get back. I’d try to be as objective as I can, but still I miss something when listening those three capacitors. If I should score the Duelund CAST Ag at 10, all of three above will get between 7.5 to 8. It’s quite good, right? Since the price different between Duelund CAST Ag and those three capacitors also very huge. Audio Note costs about US$ 55 each, Jensen around US$ 100-120 each (all 0.47 uF). The Duelund CAST Ag could cost over US$ 600 each! At fraction of cost, definitely those reviewed capacitors above have performed excellent sonic performance for most of my daily usage (the Duelund definitely not 5-10 times better as the price separates them).
VS Duelund CAST Ag:
Shortly after finished the comparison, I soldered back my Duelund CAST Ag (my current reference, priced around US$ 1500 /pair 1 uF). Well surely this capacitor is at different level with the previous three (again at 5-10 times price different). The high resolution is there, the vocal maintains its sweetness, staging is superb. All in perfectly harmony. I would say its musicality and microdetail are what we are talking about. All the tones seemed so balanced, well controlled, and proportional. This is the first capacitor which I could listen the Classic, Vocal, Jazz, or Pop, without afraid of losing their balance. Well, you got what you’ve paid though 
