Output Caps, Final Round:
BEST OF THE BEST electrolytic capacitors duke it out for a place in my no-holds-barred PCA.
The majority of my listening tests for this round were performed through ATH-M50 headphones, which I have found to be invaluable for giving an honest rendering of sonic differences. These findings were confirmed through further comparisons using my HD598 and also feeding my Tripath->Aurasound system. Sources were a wide variety of FLAC files played both from my XDuoo X3 or my Mac's ECHO soundcard. This test was intended to compare caps of similar size that will fit into the available space on my PCB for this particular build. Voltage and capacitance ratings thus vary across caps tested, but all caps are 10x20mm unless marked with an asterisk, which means they are 12.5x25mm.
Elna Cerafine
values tested: 16V 330uF, 25V 220uF, 25V 470uF*
I can see why a few people like these more than Silmics. They have more midrange forwardness and bite to them, and at first blush seem to offer a more engaging sound. However, their treble can be a little harsh after a while, and the response is rather poorly extended on both extremes of the frequency spectrum, resulting in a less detailed, somewhat boomy and congested sound, with noticeably less bass control than the Silmic. Not my cup of tea.
Elna Silmic II
value tested: 16V 220uF
Bass has rather flawless texture, speed, and extension, even with a marginally undersized 220uF cap. A polite, soft midrange and treble makes you want to crank the volume, and the overall sound is nice and full. It hides the flaws of harsh recordings, but also seems to push vocals farther away and hide some harmonic texture, resulting in an odd hollowness in midrange timbre. I'd say these sound spacious due to decent extension and a somewhat exaggerated treble sparkle, but the high treble is missing. I particularly dislike the way these do metal percussion. Cymbals and hi-hats do not sound realistically metallic. Other than that, these sound great, if slightly veiled in parts of the spectrum.
Nichicon Muse KZ
value tested: 25V 330uF*
Nice. These are quite detailed, with a beautiful, jangly midrange and sparkly treble that gives an incisive "electric" sound to the upper ranges. Vocals really jump out and grab my attention so that song lyrics have excellent intelligibility. The overall presentation is ever so slightly on the hot/forward side of neutral, with a hint of upper mid harshness, but the overall timbre is natural, with enough treble to give an open soundstage. Metal strings and percussion sound right. This size gives impactful, fast, and detailed bass with my 50R cans. With these, I never feel like I'm missing any detail whatsoever, and I wouldn't say the soundstage is huge, but certainly bigger than either Elna. They're lightning fast, and darn revealing.
Panasonic FR
value tested: 25V 1000uF
I've described these before, but I'll compare them here to the others in this lineup.
- They're really just better than the Cerafine in every respect.
- Compared to Silmic, they have a strikingly similar smoothness in the mids, but this time the effect isn't exaggerated by a contrived treble sparkle, maintaining a more natural timbre overall. FR has much more clarity and extension than the Silmic in the high treble, for a wider soundstage with real air. I chalk this up to less distortion. Switching from Silmic to FR is like lifting a thin veil. Chimes and cymbals are simultaneously less fatiguing and more realistic. Bass is powerful and full, with effortless extension from the 1000uF size, but a little less textured than the sweet Silmic bass. In fact, I'd say the entire presentation is a little "slower" than the Silmic, which has a bit snappier attack. Most importantly, these FR are even less fatiguing than the already smooth Silmic. There, I said it.
- Compared to the Muse, this FR sounds a lot smoother, with much less of that addictive Muse midrange texture, and a slower transient attack speed. FR has a cooler presentation, with more extension up high, and slightly less distortion throughout the spectrum. Bass isn't quite as punchy nor textured in the midbass region as what the Muse puts out, but upon listening back and forth, I feel the FR bass is more neutral, with deeper extension due to more capacitance. FR has a better soundstage due to its superior treble transparency, and sounds less fatiguing. I'd say the two are evenly matched for detail, with the KZ giving more speed and midrange zing and overall a fuller body, but the FR letting more micro details come through the mix by virtue of clearer imaging and a more neutral signature.
Conclusion:
FR is the only electrolytic I have heard that actually gives this amp an expansive soundstage, with real air, even with a closed headphone. Silmic and Muse, while both great in their own ways, always sound "on my ears" while with the FR, music seems to come from slightly "beyond my ears". The FR sound has a certain magic to me because it sounds less dense than the other electros, highlighting the silence between notes and giving instruments a good amount of breathing room. The subtle but delicious consequence of this effect is that "space" is better represented through a delicate rendering of reverb tails and other subtleties of the recording. I can listen to the PCA more comfortably at higher volumes with the FR than with any other cap--it never grates me in the least. Most importantly, its neutral signature encourages me to just kick back and enjoy the music instead of analyzing the sound and wishing for improvements--something that can be quite hard for me with other caps. Silmic and Muse sound great, and each have subtle tonal colorations which may certainly appeal more to personal tastes or give great synergy with certain equipment. But I feel that if measured, the Panny would show significantly less distortion than either of the others. That's how it sounds to me, anyway. YMMV. Try them and see!
