The Jupiter HT line of capacitors utilizing aluminum foil in beeswax impregnated paper dielectric has been a favorite among audiophiles for quite some time. This unique dielectric and construction technique has resulted in an extremely unique capacitor that has emphasized an organic, natural presentation with the goal of minimizing synthetic, plasticky taste in many "modern" capacitors utilizing non-natural materials. The original Jupiter beeswax capacitor did have issues with the wax tending to melt at high temperatures, but the current "HT" version uses improved wax impregnation techniques and reinforced paper dielectric, resulting in temperature stability to 70 degree Celsius/158 Fahrenheit. It is proudly manufactured in U.S.A. with cryogenic treatment to top off with that proverbial cherry. With all that effort, it is also somewhat of a bargain capacitor as far as audiophile capacitors are concerned at around $36 each for one 0.22 uF/600V capacitor, which is on the low side these days when a capacitor can cost multiple hundreds of dollars easily.
Not resting on its laurels, Jupiter Condenser Co. has just launched a brand new line of capacitors called Jupiter Copper Foil Paper & Wax. It is said to be the end result of quite a painstaking process to come up with an all-new design that will outperform the already-satisfying aluminum foil paper & wax capacitor. Obvious from the name, pure copper foil replaces aluminum foil, and wax impregnated paper dielectric is used along with the 20 ga solid core silver leads from other Jupiter capacitors. However, the exact details of how Jupiter Condenser Co. managed to tweak, innovate, and listen in order to arrive at this wonderful new capacitor will remain understandably proprietary.
Jupiter Speaks, e.g. The Duelund CAST PIO Question
After the usual long period of time spent on my burn-in contraption, the Jupiter coppers were installed where Duelund copper used to reside. Even after a long burn-in process, capacitors tend to still need time to "settle" into the component after being soldered in. The quick and dirty initial impression before the Jupiter fully settled in was that Duelund had more bass bloom and quantity while Jupiter had more midrange quantity and lucidity. Audiophile electrons were allowed to percolate for some time, then more listening impressions were gathered.
With Duelund, bass lines sounded somewhat round and bloomy rich but with good growl and weight. Jupiter presented bass with more drawn-together compactness and pop especially in the upper bass which is important in driving the music forward in propulsive pop or rock. Jupiter seemed to trade away a tiny bit of bass growl and cushiony bloom in favor of more definition and control, which will likely be welcomed in many systems as many home systems fight bass nodes and lumps.
Difficult female vocal tracks with hardened shhh sibilance were presented more gracefully and naturally by Duelund, which is one of its more endearing qualities. Those who abhor digital Redbook due to irritatingly unnatural, spitty, or metallic sibilance may well find panacea in the Duelund CAST PIO. Sometimes a little oil in the dielectric goes a long way to smooth out some kinks. There was still a lot of detail resolution with Duelund, with bell-like clarity preserved in female vocals. Given the more apparent midrange energy of Jupiter, it was somewhat surprising to find the Jupiter handle sibilance so well on borderline-quality recordings. If one could draw up a graph showing resolution vs. forgiveness, it would be difficult to strike a finer balance than Jupiter has. It is quite obvious that actual human beings spent countless hours tuning the final sound balance by ear, as the final result could not have been due to sheer luck.
Another charming attribute of Duelund has always been the ample amount of low midrange richness and chest resonance preserved in voices like Leonard Cohen and Johnny Cash. Deep, rich low-midrange combined with aged rasp comes through with both alacrity and body-shaking resonance. This is one area that seems to be a special calling card for top class paper-in-oil capacitors, and Duelund PIO does it as well as they come. Jupiter copper also possesses great low-midrange richness and color that far surpass most of the competition, especially those using synthetic dielectric, but if extra PIO flair is needed, well then only a great PIO will reproduce that exactly. The question of which is more "neutral" or "true to source" is another matter entirely, one that each listener must decide for himself.
While Duelund is much better than traditional PIO's when it comes to macro dynamics and sheer bass impact, Teflon die-hards will still wish for a little bigger dynamic contrast and impact. Compared to Duelund, Jupiter dishes out dynamic shifts more briskly and powerfully. Drums are more compactly impactful like tight-fisted Bruce Lee punch. On the other hand, the slightly defocused bass foundation of Duelund can present the acoustic venue with more ambient air and resonance. Who goes to a live acoustic concert and marble at how tight the bass is anyway? For those who have been around the block a few times, this effect is akin to how good vinyl bass can reproduce the air and feel of the live venue better than Redbook CD's with tighter bass. However, if a dance, rock, or electronica party is thrown, Jupiter would be the better choice, and really, this is a great feat for a capacitor with waxed paper(!) as dielectric.
Although Duelund CAST PIO does not sound dark, closed-in, or veiled like many PIOs can, it would not often be mistaken for a full-blown Teflon affair with heroic clarity and microscopic detail resolution; close but not quite. But then again, this slight defocusing and envelopment may be adding to Duelund's organic, natural presentation so many audiophiles crave. On the other hand, Jupiter copper foil capacitor presents an enormous amount of detail and clarity, which is a major improvement over the aluminum Jupiter capacitor. I am not sure how exactly this was achieved without the aid of things like Teflon and silver, but the Jupiter does not have to make apologies to the best high-tech, modern capacitors when it comes to transparency or detail resolution. That is not necessarily to say it has completely matched or exceeded the best Teflon capacitors in this regard, but it is so good that more is not needed for musical enjoyment. In fact, Jupiter lays out its own magic mix of excellent color and richness on top of the unusually high clarity and transparency, which many Teflon capacitors struggle with, save for perhaps the wonderful Vcap copper Teflon capacitor.
Another interesting difference worth mentioning is how Duelund and Jupiter present 3-D, spatial information. Being PIO, Duelund has a more laid-back, expansive, air-cushioned soundstage presentation. For example, multiple singers in an orchestral choire are more enveloped in cushions of air with the space between singers more emphasized and charged with live energy. Jupiter emphasizes the individual singers more who are presented more clearly in the hall with more individual detail. However, the air between them is less enveloping and airy, being instead more clean and tidy, if that makes sense.
Jupiter Condenser Co.
Duelund Coherent Audio