2020/11/27

New updated - "Sound Lissajous Meter" ver 2.0

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"Sound Lissajous Meter" has been updated to ver 2.0 now!

"Sound Lissajous Meter" is an app that displays the audio signal as a Lissajous curve in real time.

Lissajous is a plane figure obtained by combining two single vibrations that vibrate at right angles to each other.

With the microphone input signal on the vertical axis and the reference sine wave on the horizontal axis, it can be displayed as a two-dimensional curve with lissajous.

In the latest version, it extends the frequency setting capabilities of the reference sine wave to include 1/3-octave band, 12-tone equal temperament, and arbitrary frequency input.

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For example, you can play a sine wave of the same frequency as a reference sine wave signal from an audio system and observe its frequency and phase changes in the pattern of a Lissajous curve. If there is a lot of noise, a noise filter can be applied to make the display clearer.

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In the case of unknown sources, the interrelationship of amplitude, frequency, and phase with the reference sine wave signal will help in the analysis of that source.

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Please click the link below to see "Sound Lissajous Meter" product page on AppStoreTM.

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posted by toons at 17:58 | News

2020/11/26

Origin of Nintendo

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Go south along the Takase River through Gojo-Rakuen, and go west on Shomen street.

There is a quaint building on the north side before Shomen-ohashi bridge.

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Nintendo's former headquarters building, built in 1930.

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Nowadays, Nintendo is a global big game company, but when it was founded about 100 years ago, its main business was the manufacture and sale of playing cards, and it was also exporting them overseas.

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The birthplace of Nintendo. Apparently there are several buildings along the road.

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This old building will be renovated to become a hotel designed by Tadao Ando Architecture Institute.
It is scheduled to open next spring, but it seems that renovation work has not yet begun, probably due to COVID-19.
.t
posted by toons at 10:44 | diary

2020/11/24

Autumn leaves of Chishakuin Temple in Kyoto

On the national holiday last weekend, Kyoto City was full of tourists, even though the third wave of COVID-19 is expanding now.
It may be the last congestion of the year since the government's travel campaign will be suspended shortly.

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I tried to avoid going out as much as possible, but on the last day I chose a less touristy spot to take a walk.

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I went to Chishakuin Temple in Higashiyama Shichijo. As few tourists come here in the fall, I was able to relax and watch color gradation of autumn leaves.

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In the vast temple precincts, I could see many autumn leaves in the vicinity of the bell tower and Kondo.

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It was a pity that so many leaves had fallen. The peak of the fall foliage may have been in the middle of last week.

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.t
posted by toons at 19:51 | diary

2020/11/20

Oike-zakura blooming!

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"Oike-Zakura" is in bloom!

It is the lone cherry tree in the corner of Kyoto Oike-Souseikan, a type of winter cherry tree. It begins to bloom in the autumn season and continues to bloom until early spring.

"Oike-Zakura" will delight passersby on Oike Street even in the cold winter.
posted by toons at 19:57 | diary

2020/11/19

YAMAHA JA-2070 - the masterpiece full-range speaker unit with beryllium center cap

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YAMAHA once sold high-end speaker units to the public. That was about 40 years ago, during the golden age of audio in the 1980s.

There were several speaker units that had a particularly strong presence in the market. It is a product line made of pure beryllium diaphragms, which was developed in the NS-1000M speaker system.

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The first of these is the JA-2070, an 8-inch full-range speaker unit with a beryllium center cap. Some from the speaker unit catalog at the time.

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YAMAHA introduces the JA-2070 full-range unit as one of its representative products in the audio history "YAMAHA HiFi History" on their website.

[ The History of HiFi / JA-2070 article excerpt ]
Since the introduction of the JA-6002/JA-5002 that were installed in the first natural sound speakers, the NS-30/NS-20, Yamaha has always sold main speaker units separately, targeting high-level amateurs putting together their own speaker systems. In particular, the long hoped-for high-end units featuring the beryllium diaphragm developed for the NS-1000 series and FX-1 attracted worldwide attention, with a full lineup including professional items such as a large sectoral horn driven by two drivers in parallel introduced around 1980.

A particularly bright star in the lineup was the JA-2070, a 20cm full range unit featuring a beryllium center cap. This unit, not actually used in commercial speaker systems, was developed for the DIY enthusiast set. With an aluminum-nickel magnet and specially treated white paper cone diaphragm housed in a 50ℓ bass reflex cabinet, it featured wide-range characteristics capable of full flat playback from around 60Hz to over 20kHz. The JA-2070 model aimed to surpass the JBL LE-8T, a renowned full-range masterpiece, with modern technology. At 65,000 yen per unit its price greatly exceeded that of the LE-8T. Extravagant while still insisting on simplicity, it remains a hidden gem among Yamaha's speaker units.

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Specifications:
Model type : JA-2070, 20cm cone type full range
Nominal Impedance : 8 ohm
Playback frequency band : 20 Hz - 20 kHz
Rated input : 20 W
Maximum input : 40 W
Output sound pressure level : 91 dB/W-m
Voice coil diameter : 52.7 ƒÓmm
Equivalent mass : 14.6 g
Qo : 0.59
fo : 35 Hz
Magnet : Alnico, 0.77 kg
Magnetic flux density : 11,000 gauss
Total flux : 200,000 Maxwell
Recommended box capacity : about 50 liters
Dimensions : diameter 213 mm x height 116.5 mm
Weight : 5.0kg

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In fact, I currently own this special full-range unit, JA-2070. I bought it new and have been using it for almost 40 years. It is one of my audio treasures.

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The JA-2070 is the origin of my sound, and it is still working and reproducing a wonderful sound. I'll write a related article about it.
.t
posted by toons at 18:55 | Audio