2018/10/29

SANSUI AU-5500 repair - 2

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Sansui's integrated amplifier AU-5500 manufactured in 1975 is being repaired.

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When removing the top panel and turning on the power, pilot LED lamp is lit properly. But the relay of the protection circuit is not released. Since smoke does not come out, I was relieved a little.

Then I heard something vibration noise from the inside. When I left it for about 3 minutes in this state, suddenly the vibration sound ceased, the protection circuit was canceled and the sound was outputted.
It does not distorted in a clear sound. But crosstalk performance are not very good feeling.

The problem is that the protection circuit is not immediately released, so there is a high possibility that something is happening around the power amp section. Therefore, I removed the bottom plate and observed the inside circuit.

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The board on which the metal can transistor is mounted is a power amplifier section, it seems to be orthodox configuration of single push pull amplifier.

A relay of the protection circuit was found here. It is quite suspicious about the protection circuit and the driver stage.

A little observation, I understood that the deterioration of parts of the electrolytic capacitor on this board has advanced considerably, and it seems to be the main cause.

Since this board is facing downward, it is easy to cause thermal deterioration of parts due to heat inevitably.
Although there are plenty of space inside the enclosure, it is mysterious why this configuration was made.

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This electrolytic capacitor, the electrolyte inside is expanded and is diagonal. Actually, the bottom half of the part is blackened with fever and the electrode is loose, so I think that it is on the verge of explosion. That vibration noise also seemed to be a source generated by this electrolytic capacitor.

So, I think that it is necessary to replace the inside of the deterioration parts in order. It should be repaired for each board separately as a whole. Fortunately, the power transistor seems to be alive, so it may be possible to replace with the minimum parts.

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I will clean up first because the dirt is stuck to the whole of this amp. Although only the front panel has few scratches, silver switches and knobs were stained in gold by cigarette smoke. It seems to have a long way to go.

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posted by toons at 09:11 | Audio

2018/10/28

Naginata - Sailor's special nib fountain pen

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SAILOR Profit 21 Naginata sharpening model - Rhodium - medium fine (NMF)

It is Sailor's special nib fountain pen, Naginata sharpening model. It is said that this fountain pen is the most easy to write Japanese character.

This is special one that had produced the master nib designer, Mr. Nobuyoshi Nagahara.

He died in 2015, and production of the special nib fountain pen ceased.

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The special pen nib was sharpened by handmade, so its production quantity was very small, it was produced only by reservation.

My Naginata fountain pen is a medium fine pen tip (NMF), but it is comparable to bold (B) at the pen tip of a normal fountain pen.

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For the first time, when I wrote a letter using this fountain pen, I was amazed at its splendor.

It is a distinctive writing taste that the ink flow is very good and feels like being dancing on paper.

In addition, the soft and supple feeling peculiar to 21 gold is easier to write than any fountain pen you've used and you can write powerful letters smoothly.

The picture below is a nib shape of Naginata fountain pen. You can see that the pen tip is very large and it is being scraped like a long sword.

A unique line that becomes thick if you put the pen down, and becomes narrow as you stand, is created from this shape. You can freely control the character expression with kanji depending on the angle of the pen.

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The other day, when I was investigating fountain pen related information on the web, I found that SAILOR was resumed to sell the special fountain pen including Naginata sharpening from October 5, 2018 in Japan.

I am very pleased the resurrection of "Pen tip is SAILOR !".

According to news, Sailor seems to resume production and sales with new specifications and prices with the special fountain pen including Naginata sharpening.

http://www.sailor.co.jp/lineup/fountainpen/10-7112

Reference)
Types and features of pen tip by Sailor:
http://www.sailor.co.jp/knowledge/original

English Sailor web site:
http://sailorpen.co.uk
posted by toons at 09:01 | diary

2018/10/12

New updated - "Audio Tone Generator Lite" ver 4.0 - Free of charge!

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"Audio Tone Generator Lite"has been updated to ver 4.0 now.

"Audio Tone Generator Lite" is a free app that has simplified the sound generator function of "ATG - Audio Tone Generator" app.

"Audio Tone Generator Lite" creates the audio reference signals as Sinewave, Sinewave Sweep, White Noise and Pink Noise.

It will help you to make the sound benchmark for your audio equipment and loudspeakers, your listening environment and room acoustics or your hearing.

The signals created by this app can be best used in conjunction with external devices, such as an audio spectrum analyzer or a sound level meter.

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If you are interested in this app, please click the following link to display on the product information of App StoreTM.

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posted by toons at 16:55 | News

2018/10/11

New updated - "ATG - Audio Tone Generator" ver 5.0

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"ATG - Audio Tone Generator" has been updated to ver 5.0 today.

"ATG - Audio Tone Generator" is a powerful reference Audio test signal generator app for iPhone.

It will help you to make the benchmark for your audio equipment and loudspeakers, your listening environment and room acoustics or your hearing.

The audio signals created by this app can be best used in conjunction with external devices, such as an audio spectrum analyzer or a sound level meter.

This app creates the reference audio test signals as Sine-wave, Frequency Sweep, White Noise and Pink Noise, and has a high precision of CD quality and a frequency accuracy of 0.1Hz. Frequency Sweep time can be altered as desired by the user.

It can also generate octave band noise of 1/1 or 1/3 octave in NOISE mode. You can use it for detailed analysis of specific frequency bands.

In addition to AirPlay, it supports to Bluetooth communication newly.

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Applications:
- Testing for Loudspeakers and Headphones
- Burn-in for Audio equipment and Loudspeakers
- Testing and tuning for Audio amplifiers, Equalizers and many other Audio equipment.
- Acoustics testing
- Frequency response measurement for Audio systems using White noise and Pink noise
- Sound Masking
- Relaxation and Meditation
- Hearing Test
- Mosquito sound creation for teenagers

If you are interested in this app, please click the following link to display on the product information of App StoreTM.

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posted by toons at 18:59 | News

Thanks for 6th anniversary of TOON establishment.

Our company celebrated the 6th anniversary of establishment on October 11 today.
We would like to offer new sound and environmental solutions in the future.
Thank you very much all for your support and gratefulness.

October 11, 2018
TOON, LLC.
posted by toons at 18:57 | News