Russian K40y Paper-In-Oil Capacitor
I must thank “Bob B” and “Les Lemmars” for kindly loaning me these K40y caps. After the usual rocky burn-in ritual, this PIO cap settled into a confident, natural sounding device. There are some audiophiles who rank these PIO caps as the best of the Russian military caps, including the FT-3 and K72 teflon caps. I may agree with this sentiment when it comes to utter naturalness and ease of presentation as well as the lack of a subtle “plastic” sound, which of course all plastic (film) caps have.
Gladly, this PIO cap did not have an overly dark, laid-back sound some people may expect of PIO caps. The important midrange energy was quite forceful and engaging as well as richly harmonic. The rendering of textures was most reminiscent of a good vinyl setup, which is a good thing; and detail resolution was not lacking, either, but the extreme “air” on top was not as beautifully alive as with VCap teflons. Speaking of teflons, the only real reservation I have about K40y is in the bass. The VCap Teflon, K72, FT3, Sonicap Platinum all seem to have a tighter control over basslines with sharper leading edges and snappier decay. K40y’s bass is more woody, richer, but just shy of the vise-grip crunch, so if you’re a death-metal or electronica fan, K40y may not get you to the promised land.
Overall, I really enjoyed the K40y. Its raison d’tere falls squarely in the critical midrange, where tons of texture, bloom, and natural detail anchor the music without that subtle synthetic feel of many other caps. Although the voices aren’t brightly spotlit, there is a magical highlighting and intensification without turning bright.
Dare I dream of oil-impregnated foamed-teflon silver-foil capacitor…?
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Vishay Roederstein MKP-1839 Metalized Polypropylene Capacitor
Audio Circle member “slbender” was kind enough to send me some less-than-exotic caps to evaluate, including the Vishay MKP-1839. His view is that most caps of similar construction, e.g. metallized poly, should sound very similar, no matter the brand or price. This was a good exercise for me because it helped with the “Big Question” that must be lurking in the minds of many audiophiles: are these expensive, exotic capacitors worth it?
Vishay MKP-1839 is the axial version of the more famous Vishay Roederstein MKP1837 (a.k.a. ERO MKP1830), which is touted as a good bypass cap, and represents a well-made, inexpensive metallized poly cap. And as it turns out, it also sounds good as a coupling cap. Upon casual listening from a casual house guest, for example, it is unlikely he will jump up and down and scream, “Put back that other capacitor X ASAP!”
MKP-1839 sounds pretty well-balanced, without obvious peaks or valleys, and pleasant; it is less hard-sounding than, say Solens. In fact, one can only wish manufacturers would use caps like MKP-1839 in their cheaper, generic audio gear. So, why should you pay more for your cap?
The most important difference between MKP and some of the better caps is the weight behind the notes. I’m not talking about bass weight or warmth but the fully fleshed-out, 3-dimensional harmonic energy behind each note, be it in treble, mid, or bass. Lacking this, soprano, chime, flute can sound just 2-dimentional and thin, failing to fully make you believe.
The other significant difference is in dynamics. The MKP doesn’t sound too lacking until you compare to the better caps. A “pop” or “thwack” via MKP sounds like a fighter who is punching to save his neighbor’s life whereas via a better cap, he sounds like he’s punching to save his own life. Similar difference in microdynamics as well; better caps simply let the small nuances and subtleties to bubble to the surface with easier effervescence and life.
I still don’t believe any of this truly answers the question whether exotic caps are worth it because the answer will depend on one’s gear, tastes, resolution level of the system, musical choice, pocketbook status, and simply how crazy you are. Time to enjoy the music, either way, any way…
