Jupiter is the far better choice ...... if you want more inner detail, richness and spot-on tone. The Jensen cap is very good, but not as neural top to bottom with an obvious darkening and thickening of the sound
LErik is so right. Try them. For me and others they are just too forced and tilted up in the presence area. My ears could not relax with them. Others love them. If you like tilted up upper mids and highs and the perception of uber detail, then you may like these. Perhaps your system could use this presence area boost? Perhaps not? You know your current sound and what you are looking for sonically.
I have never had an issue with Jupiter copper foils leaking or breaking down in any way over the years. I have with Duelund and Jensen however. Jupiter is richer sounding than Vcaps with better meat on the bones weight and body. Vcaps are more resolving and sharper leading edges. However this resolution comes with a slightly thinner sound.
I used the Jupiter caps in varied positions in all kinds of gear (crossovers to amps) so my comments are based on use beyond one or two products. I must have upgraded and modified at least 30 DIFFERENT audio pieces with this cap...perhaps more. With all things audio the end result is often gear and system dependent. No doubt in your two pieces, your particular design and flavor, that was your experience.
However, the Jupiter copper foil cap is wonderfully balanced top to bottom with no part of the sound spectrum emphasized. This is evident when used across a wide spectrum of gear, not just one line. This is also consistent with a plethora of professional and manufacturer reviews including Humble.
As always these caps need over 200 hours of break in before judging. This is especially true of Jupiter and Vcaps.
I used the Vcaps copper ones and very pricy. Very long run in period. They were simply too thin sounding to me, but very resolving for sure. I also like the HT Jupiter capacitor in beeswax. Nice tone and very organic sounding. Not as much air and inner detail as the copper foils, but good for sure and less money.
I suppose one’s sonic priorities and tastes are at play here. I am not a detail guy. I am more of a tone and body guy.
Yes the Jensens are darker than the Jupiter copper foil as pointed out. They will open up a tad, but won’t deliver in the highs as extended and sweet as the Jupiter. They have the personality you are currently hearing even after burn in. They are known to be a tad rolled off and very “polite” in the highs. I also find them thicker in the upper mids.
My experience is the Jensen’s, in tube gear and dacs, are just darker than the Jupiter or Duelund copper foil caps. I also modify and upgrade gear for a living and do all manner of upgrades with caps. Jensen are good caps, but not as good in the micro details, resolving , and air as the Jupiter copper foil or Duelund. These areas seem to reflect the sonic need of the OP so I am specifically talking about this “presence” area of the spectrum. . Vcaps copper are also more extended and resolving.
A good option, keeping what you now have, is to bypass your Jensen with the Duelund pure silver .01uf bypass cap from Parts Connextion. I have had great results with this combo in electronics. You will definitely get more air, sparkle and resolution. More realism!