I have been a fan for Black Gate for quite long time. My first time impression probably nearly 10 years ago. I forgot whether I heard SKz or WKz at that moment, but I did remember the beauty of tube amplifier, smoothed by those Black Gate (probably not just Black Gate who contributed for the amazing sonic at that moment).
But 10 years back, I didn’t dare to play hundred of Volts for designing tube based equipment, then high voltage Black Gate such as SKz or WKz was out of my consideration. I got some and sell some… Mostly, I preferred to play with NX series, which very common in low voltage application (as low as 6.3 Volts). Very useful in D/A application. Some people say the Black Gate NX (especially the HQ – High Quality version) is very good in D/A coupling application. It produces very neutral sound, transparent, almost nothing (like direct coupling). But some people don’t like this kind of ‘sterile’ sound. Not analog, some people complaint.
Actually, other best application for Black Gate NX series is on the power supply smoothing section, especially on the D/A side.
I still own several N/NX/Hi-Q series, FK series, F series, PK series, Standard series, C series, and off course, the latest acquisition, SKz/WKz series.
All the latest WKz series (not WK, SK or SKz) will have a green ‘Goddess playing harps’ and ‘Heart of Muse’ text. Actually, Black Gate is not the only one who uses ‘Muse’ in their capacitor series. We also can find Nichicon who uses ‘Muse’ in their line up. Term ‘Muse’ itself (one of them) could refer to any of 9 daughter of Mnemosyne and Zeus. Still on the same mythology, each of the Goddess possesses specific art or science. Probably this one loves music…
Below is example photo of Black Gate SK series. I’m not so sure when was this capacitor released, but I think it was quite long time ago. As for current production, we only recognize WK, VK, and FK. I think this should be around end of 80’s.
Newer, but not the latest. SKz was predecessor to WKz series (which was officially announced on Jelmax Technical Report #104). I haven’t done any comparison between SKz and WKz. Not really necessary to do such comparison anyway 😉
The latest one, WKz ‘Heart of Muse’. I have moved out from electrolytic long time ago (and acquired film capacitor on the power supply, like Solen, Obbligato, Unlytic, Mundorf, Jensen, etc). But few years back, I was quite impressed with Jensen 4-pole which wass actually an electrolytic based capacitor. I’ve never been impressed like that before. Then I remembered with the old Black Gate WKz. Tried to call some of my colleagues, and got one of them still have some stock. Finally, I got those Black Gate WKz back on hand. Not cheap though, but for the sake of ears, sometime we could do out of what most consider as ‘rational thinking’.
What makes this Black Gate different from typical capacitor? Well, Black Gate incorporates Graphite fine particles on the separator between Cathode and True Cathode section inside the capacitor. The point? To improve the ion transfer between Anode and Cathode.
Don’t forget that Jelmax Co.,Ltd. (which ‘outsource’ the Black Gate production to Rubycon) announces that Black Gate has what they call ‘idling’ process. This is the uniqueness of Black Gate capacitor. Based on the Jelmax Technical Report #47, ‘idling’ process means the process of making paths on the separator (which contains Graphite fine particles) for the ion transfer purpose. This process is believed could take as short as 30 hours on high signal application and could be more than 1 month in low signal application. DC Volt and Signal Current are minimum requirements for this ‘idling’ process.