Oil capacitor from mica

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Summary

　Pulse sound of capacitor

Through previous experiments, it is known that the pulse sound produced by a capacitor is smaller or produces no sound as the capacitor has a larger outer shape (especially, one with a higher breakdown voltage).

In this respect, the box-shaped mica condensers and thin mica paper condensers used for coupling the 200Hz LPF and HPF with the mid-low, mid-high, and high frequencies are large in external size and do not emit any sound at all.

Waveform distortion

In the section of "Sound Laboratory / Capacitor that produces sound / Summary of the warped waveform of a laminated ceramic capacitor," it is stated that "I think it was correct to change the coupling capacitor to a large (box-shaped) mica capacitor and the filter capacitor to an SE capacitor or a box-shaped mica capacitor. I think it was." I wrote.

Certainly, the sound improved when I changed from pea-sized film condensers to SE condensers, large box-shaped mica condensers, and mica paper condensers.

However, in a series of experiments with sound-producing capacitors, I noticed the distortion of the rising waveform of the capacitor and came to believe that the mica capacitor passed the test in terms of pulse sound, but failed in terms of waveform distortion.

By switching to box-type mica capacitors, there is a (+) in terms of sound quality in that the capacitors do not produce sound, but there also seems to be a (-) in terms of waveform distortion.

If we can solve this minus, the sound could be even better.

In other words, distortion (distortion) of the waveform at the rise of the sawtooth wave may be causing distortion (distortion) of the audio signal as well.

◆Mid and high frequency coupling capacitors

◇Condenser used

I used a 0.1μF 2000V high-voltage oil capacitor (Photo 1-①) to replace the 0.2μF box-shaped mica capacitor that I have been using.

Since we only had two of these capacitors on hand, we decided to check the sound with 0.1μF for the time being.

The pulse sound and the rising waveform of this high-voltage oil capacitor have already been confirmed in the previous section, so we know that there is no problem with it.

Installation

Crimp terminals are attached to this high-voltage oil capacitor as shown in Photo 1.

Since the box type mica capacitor is a screw terminal type, it is to be able to replace it easily with a screw.

Photo 1: High-voltage oil condenser

From the top

①0.1μF 2000V (WV), 5000V (TV)

(2) 0.2μF 1200V

(3) 0.1μF 1200V

◆Listening Results 1

The first impression was that there was no noisy sound even when the volume was set at 11 o'clock, which is usually set at 9:30 or even 10 o'clock when the volume is high.

This is the first time I have listened to the sound at this level.

I found the mids and highs to be beautiful and the distortion to be reduced.

I listened to it again the next day to see if it was not too much distortion, but it still did not sound noisy even when the volume was turned up.

Sources used for listening

No. Song name Favorite source

CD & SACD

Reference page / Remarks

1 CD: Ayako Uehara

　　　Live at International

　　　Tchaikovsky Competition" 2002 TRITON

DICC-25002

0.8μF coupling capacitor for mid and bass

So far, I have been using a mica paper capacitor 0.2μF in quadruplicate.

This capacitor also has no problem in that it does not produce pulse sound, but I noticed that the distortion of the rising waveform is the second largest among mica capacitors, and I was beginning to worry about the distortion in the mid-low range.

◇Condenser used

For the mid-low range, I decided to use 4 high voltage oil capacitors 0.22μF 1000V in parallel.

I found this capacitor sold as a coupling capacitor and bought eight of them for the mid-low frequency band, knowing that they would fail.

Fortunately, I was relieved to find that the measurements in the previous section showed no problems in terms of pulse sound and waveform distortion.

In addition to the above, I also bought two 0.1μF capacitors in this series, which I intend to use for treble tones in the next step.

I will also add them to the coupling capacitors for the mid and high frequencies.

While replacing this high-voltage oil capacitor, I added 0.2μF and 0.1μF 1200V high-voltage oil capacitors shown in Photo 1-② and ③ to the aforementioned coupling capacitors for the mid-high range.

The left side is 0.2μF and the right side is 0.3μF, but since they are coupling capacitors, there is no problem.

Photo 2: High-voltage oil capacitor (new)

0.22μF 1000V made by Toichi Electric Co.

Non-Inductive Vitamin-Q Oil Paper Cap

(Purchased from Sanei Denpa Co., Ltd. in Akihabara, Tokyo)

◆Listening Result 2

My first impression was the beauty of the sound in the mid-high range.

I was delighted again by the beauty of ADAGIO LA QUARTINA's cello.

I also listened to other CDs as shown in the table.

The most significant features are the fresh and clear sound of the mid and high frequencies and the fact that there is no grating sound even when the volume is turned up.

Since I have said the same thing over and over again every time I make improvements, I am left with the phrase "even more" fresh and clear sound, but it would be more accurate to say that it is the first fresh and clear sound I have heard, not just "even more".

Sources used for listening

No. Title Favorite source

CD & SACD

Reference page / Remarks

1 CD: ADAGIO LA QUARTINA No10

2 CD: Cello Cantabile No-19

3 CD: J. S. BACH　

　　　Sonatas and Partitas

　　　for Solo Violin Volume1 NAXOS

8.555422

4 CD: DIE KUNST DER FUGE No20

5 CD: Emmanuel Pahud

　　　Brandenberg Concerto No14

6 CD: Amazing Grace

　　　～Best of Gary Carr No3

7 CD: Ombra My Who

　　　Gerry Carr Plays Opera Aria No9

◆Summary

Difference of ◇Condenser

I knew that the mica paper capacitor I had been using was causing sound distortion.

Also, the above high-voltage capacitor sold as a coupling capacitor may be a really good capacitor.

The label on the unit reads "Non Inductive Vitamin-Q Oil Paper Cap TONE FACTORY TOICHI," which indicates that the condenser was designed with sound in mind.

According to the store, this condenser has been well received as a coupling condenser for vacuum tube amplifiers.

If this capacitor had been available 42 years ago, we would not have suffered from the irregular low frequency oscillation of 6080 low RLOTL amplifiers.

◇Expectations

So far, we have used a box-shaped mica capacitor for the 0.1μF coupling capacitor for treble, 200Hz LPF, and 0.1μF for HPF.

If the sound changes this much, I have high expectations that the sound will be further improved by replacing these capacitors with oil capacitors of high withstand voltage.

◆Issues

Distortion of sawtooth waveform at several kHz

We imagine that the distortion in the rising waveform is due to the formation of a high-resistance battery or capacitor inside the capacitor.

The frequency of the series of waveform observations is as low as 10-25 Hz, so it is affected by this.

If this theory is correct, waveform distortion would be negligible at high frequencies.

You should be able to tell by sweeping the sawtooth waveform of the capacitor with the frequency set between 5kHz and 20kHz and observing the waveform distortion.

As for the pulse sound, the laminated ceramic capacitor produces the loudest sound.

In addition, there is a voltage dependence of capacitance, and the sawtooth waveform has an upswing.

The laminated ceramic capacitor is used for decoupling capacitors, and although I appreciate that there seems to be no problem since it is an application used at a constant voltage and the sound is also good, it is the capacitor that I have been concerned about from the point of voltage dependence of capacitance for some time.

In the section on amplifier sound aging/enhancing preamplifier decoupling capacitors, I also wrote, "Using one with a distortion factor, even if it is only a slight problem, will cause these things, so it seems best to avoid using them as much as possible." He writes.

I will start to re-examine multilayer ceramic capacitors after I have finished what I wrote in the summary and assignments, not at the same time here.

◆continued

　

First edition November 16, 2004