Still curious about the different between Jensen Copper Foil Paper Tube and Duelund CAST PIO, I held another session to benchmark both capacitors. You can read previous articles here and here.

This time I visit another friend. His systems as shown below. Briefly speaking, we can see a Fostex full range speaker with extra Visaton Super Tweeter. The source are Cayin CDT-17A (fully modified on its analog stage and additional reclock module) and a turntable (VPI Scout with Super Platter and Van den Hul Grasshopper IV GLA cartridge). The preamp is Tube #26 with RGN Rectifier. The power amplifier is RS241-12E1-6J5 with RGN Rectifier also.

We compare the Jensen Copper Foil Paper Tube and Duelund CAST PIO on the position between 12E1 and RS241.


The result?

For standard music consisting a lot of vocal, like Rebecca Pidgeon – Spanish Harlem or Ingram Washington, the different is there, but not that significant. Duelund wins for the harmonic details and spacious imaging – but in a small margin. While Jensen which doesn’t have that kind of details, but it could swing the vocal very well. I would say, the Duelund with around 4 times more expensive to Jensen, won’t make my jaws drop on the floor.

But situation changes completely after we switch to an even more complex music, with various instrument (most likely, consisting a lot of cymbal or brass and live music environment). We take some track from Sheffield Labs and some other more popular like Coal Train/Stimela by Hugh Masekela. With these kinds of music, we do really enjoy the advantage of Duelund CAST PIO. The music sounds live, a real live music and harmonically rich with huge and spacious imaging. It only take few second after the first tone played, before we can say, the Duelund is definitely better than the Jensen. Does it worth the 4x more expensive price? In this session, I would say YES! This session, Duelund CAST PIO does make my jaws drop on the floor.

FYI, mostly we use Vinyl as source. I seems that we got enough with CD 😉

Caveat: Jensen Copper Foil Paper Tube is a good capacitor, really a good one for its price… BUT… if you don’t want to get poisoned, don’t ever  hear the Duelund CAST PIO. After you hear the Duelund CAST PIO, it seems that you have no way back.


I also held an extra session with my Aikido (equipped with Duelund CAST PIO and RGN 1054 Rectifier) vs the Tube #26 Pre-Amp. I need to improve my Aikido mid-vocal though 😉


Also we held a Cayin CDT-17A short mod session. The best combination after several times testing is the 0.47uF Jensen Copper Foil Paper Tube  + 1uF Mundorf Supreme Silver/Gold/Oil. This combination provides excellent vocal with superb staging and details.