Fall 2008

Capacitor Musings Part 2
Article By Jon L.
Page 3

WIMA MKP10 Polypropylene Capacitor
I was absolutely shocked when I received my WIMA MKP10 capacitors. They are huge as seen next to same-capacitance AudioCap Theta and Auricap in the picture. This German company supplies a lot of capacitors for many high-end companies, and I have seen many red-colored WIMA capacitors inside components; but I don't remember them being this large. WIMA MKP10's claim to fame is their "double-layer" construction:

"The construction principle of the series WIMA MKP 10 consists of a non-metalized dielectric film and an carrier film metalized on both sides acting as electrode. Thanks to the metallization on both sides, the electrical conductivity is considerably improved and the contact surface between the electrodes and the schoopage layer is doubled. This results in better contact and allows for high current and pulse loading capability."

The reason I am even going into such detail is due to the fact its sound quality easily exceeded my jaded expectations. It sounded quite bright at first, but after settling down, it presented a nicely-detailed, airy, and sexily breathy sound. It perhaps does not have 100% of the refinement and sophistication of Dynamicap E or Jantzen Superior Z, but its slightly more forward and breathy sound is a bit more exciting and ear-grabbing. It's not overly etched or thin-sounding, either, which you always have to watch out for in cheap metalized poly caps. I have heard some people complain WIMA lacks bass, but this was not true in my case at all, as its bass was just as good as other good poly caps. I don't know how WIMA's other caps sound, such as MKP4 and FKP, but the 630V MKP10 is a budget-champ!

AudioCap Theta Polypropylene Film and Tin Foil Capacitor
AudioCap Theta is constructed with polypropylene film and tin foil with gold-plated OFHC leads, and it is very reasonably priced compared to AudioCap PCU, which is polypropylene film and Copper foil and priced accordingly. I have read AudioCap Thetas being described as lean and clinical in the past, and that's exactly how they sounded in the beginning. However, after proper break-in, these things became extraordinarily rich and warm in tone, without any wooly, syrupy sloppiness. AudioCap Thetas definitely had another notch of detail and resolution in the mid-midrange compared to even the best metallized polypropylene caps, resulting in sumptuously textured and detailed voices; however, the upper-midrange and treble also retained this rich smoothness, which in fact made them sound a touch less open and sparkling compared to metalized poly caps like WIMA.

The longer I listened to AudioCap Theta, I was both more charmed and frustrated at the same time. It's density of tone and authoritative texturing in the midrange was very tasty, which only highlighted its Achilles' heel, i.e. somewhat dark and shut-in upper highs compared to the best. Hoping for luck, I tried bypassing the AudioCap Theta with FT-1 Russian Teflon's 1/10^th its value. Even though both caps were burned-in, the resulting sound was initially horrid: overly bright, grating, and just amusical.

Knowing these things take time, even with previously used caps, I ran them for some time, and like magic, everything fell into place. The combination was at once rich, textured, and warm, yet with intact high-frequency leading edge detail and sparkle. This casserole of sorts yielded very, very satisfying results, working much better than when I bypassed oil caps with small Teflon caps. I must presume that oil caps and Teflon caps are simply too different to gel coherently; combining more similar film caps really hit on something wonderful here.  

In fact, to check my own impressions, I put back one of my expensive Teflon references; and I honestly can't tell you I definitely prefer the Teflons. The Teflons still have a smidge more see-through transparency and smoother liquidity, but the Theta/Teflon combo has more weight and texture behind the notes while not giving up overall resolution and punch. This combo is a definite contender in the right system.

Sprague Vitamin Q PIO Capacitor
Sprague "Vitamin Q" capacitors are a beautiful example of how things used to be manufactured right. These capacitors are built like a tank and sport a special vitamin Q mineral oil to soak the dielectric; the overbuilt Russian oil caps have nothing on these NOS caps when it comes to build quality. Almost a cult favorite among DIYers over many years, Vitamin Q's certainly live up to their reputation for great sound quality.

After the usual rough period of settling in, Vit Q's came alive with beautiful tonal color, bags of textural contrast, and a sense of immediacy. There is a "wetness" to its presentation that is quite beguiling, yet it's very detailed and sparkling, definitely not polite or overly dark. If you find the Jensen copper PIO's a little too refined and buttery smooth in your system, Vit Q's might fit in very well instead. On the other hand, many audiophiles prefer that velvety smooth sound, in which case they will likely prefer something like Jensens. Both offer more openness and air compared to the denser sound of Russian K40y PIO's, but all three PIO's are capable of doing music justice with synergistic placement.

Previously I tried bypassing the Jensens with small Russian Teflon caps to add a litte more sparkle and contrast, but in the end I decided I prefer the Jensens by itself to preserve its own charms. I have no such desire to bypass the Vit Q because it seems to have enough contrasty sparkle already. Vit Q's don't sound like good polypropylene caps, Teflon caps, polystyrenes, or anything else, really, but they have a unique, involving character that's hard not to enjoy.

POSTSCRIPT (?)
I highly doubt these are the last capacitors I will ever try, but for now I can convey a few of my thoughts about this whole capacitor-rolling business. Firstly, capacitor-rolling is far from an exact science. It's most akin to cooking in my mind because the best ingredients in the world don't guarantee great final taste; they have to be utilized in right amounts to be in balance with everything else in the pot. The same can be said about audio parts including capacitors, and of course, the listener's preferences play a large part.

Secondly, the price of the capacitor does not necessarily predict the end result. While some of the great Teflon capacitors have to be expensive by their nature, there are numerous "cheap" capacitors out there that will have no trouble passing the musical signal in satisfying manner. Many expensive capacitors do sound great, as they should given their price, but a careful DIY'er can arrive at very satisfying results at a fraction of the cost, especially when total system synergy is taken into account.

Thirdly, some have requested a simpler table of rankings and scores for all these capacitors, but if you have read this article thus far, you should already have a feeling that there can be no concrete ranking by the numbers. I feel that most of the better capacitors auditioned are capable of "beating" each other depending on the specific application, taste of the listener, type of music, overall system configuration, and of course, the cycle of the moon. I'd rather not presume that my rankings are superior to other people's rankings; as long as one has tried reasonable capacitors and chose with his ears and enjoys the music, that's really all that matters in the end, isn't it?

Until next time...