November 15, 2020

Hybrid Vacuum Tube Headphones Amplifier (Part 5) Nichicon Audio KA Capacitor Review

As we are know the capacitor playing major role in audio equipment. It smoothing the ripple from power supply and for most of application is at DC blocking so only the audio signal can be pass through. The capacitor is also become an evil, meaning it dispute for the effect from overall sound performance. One may agree but many others don't and it is really okay because this audio hobby is an art to discover the best sound possible. This is including improving the components quality and one of them is changing the evil itself.

So on my hand is a quite new capacitor from Nichicon. This is KA type for audio and I eager to know how it perform.

I am really familiar with Nichicon capacitor series, quite easy to remember in my opinion.

I have good review the Muse green and Muse KZ capacitor to improve the power supply ripple rejection better. The smaller version is Fine Gold FG or FW with also have the same result in improvement.

This KA is new for me. The size is smaller, it is covered with light blue sleeve and Audio KA mark on it. This capacitor is withstand up to 105 degree Celsius which is rare to find this heat rating in the audio capacitor.

This capacitor must be built for the portable equipment which size is important.


My portable vacuum tube amplifier that I just built recently is still hot.

The capacitors used is standard but high quality from Rubycon ZLH. It sound good and very reliable. If you like how capacitor good in measurement, this Rubycon ZLH is absolutely for you. But for the sake of this review, I guess this will replace it to this Nichicon KA.


The hybrid vacuum tube amplifier here having 6 pieces of capacitor with all 220uF value. The voltage rating previously from Rubycin ZLH is 35 volt and the Nichicon KA is 16 volt. This quite unfair because based on the datasheet, the higher voltage rating mostly have more ripple rejection.

For the capacitor that built for audio have the specification not better than the industrial one. This is the example Nichicon KA against Rubycon ZLH, which is has bigger ESR and V-loss. But I will see how the label Audio KA capacitor can really have a good performance in real audio performance over the standard industrial capacitor.


So changing all capacitor on this hybrid vacuum tube amplifier only takes a few minutes. All components stay the same except the capacitors is now all Nichicon KA.



So the first time I turn on this amplifier, as usual the vacuum tube glowing bright, then I let it idle for a while to reach the optimal operating condition.

The first impression of this Nichicon KA, it doesn't glows the music very well. Overall  music performance seems more narrow and less sparkling than the previous capacitors. This sound behavior should be because the new capacitor not yet in the break-in period. I let it play for few hours and the sound now a little bit changes.

For several hours playing I can feel the new capacitor actually more emphasis in the mid-range frequency. It more transparent with more detail in it. Absolutely this Nichicon KA not on the warm side but more natural. The high frequency also quite improve, it smoother, a little bit but not as striking high as the Rubycon ZLH. I also find the bass has the same texture as before, it is not deep enough, but this is because of the amplifier design, not the capacitor itself. The overall music presentation is almost the same with previous setup and with the same sound-stage and great stereo separation.


This Nichicon KA has it own improvement but more or less the Rubycon ZLH also not bad at all. Nichicon KA is not for anyone looking for warm sounding capacitor, not also for the Rubycon ZLH. 

This Nichicon KA also has cleaner high frequency with smoother presentation. Using this Nichicon KA on portable vacuum tube amplifier give more enjoyable sound performance for sure.



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