DS Audio

1,What is ‘DS Audio’?   (Digital Stream corporation home page is here)

DS Audio is a newly formed audio business group in Digital Stream Corporation  (“DSC”) this year. DSC has been in the laser optics market over 25 years.
You may not know us, but maybe we are right next to you every day .
DSC has been known as the provider of industrial laser optics systems in the optical disc market, in Medial testing systems, and for various laser optical instruments.
Disc evaluation system, for example, is the absolute scale of optical disc error measurement, where no reading
errors are allowed. “When you see reading errors in the tests, they are caused by the disc errors 100%.”
This is our statement and is based on our 25 years of experience and track-records. Market share of 95% in Disc tester optics speaks itself for the quality and performance of our laser products.

Optical Pickup for Disc Testers      Blu-Ray pickup for Tester / Commercial

Optical mouse, for example, was co-developed by Microsoft and Digital Stream Corporation.
It has changed the world. What about USB?  USB Ver.1 was the first USB unit ever marketed through Microsoft gaming device, and Digital Stream technology was utilized. We are proud to state that  we have received “Outstanding Engineering Excellency” prize from Microsoft.
Back in Japan, we have received “300 Excellent companies in manufacturing”  prize led by Ministry of Economy, Trade and Industry in 2011.











Excellent Technical partner Prize

MS products by DSC








Besides working in the precision measurements by Laser optics, DSC has explored unique applications of laser technology such as PC input devices, Game devices, and the establishment of China National Standard in Blue discs. Those are the milestones of our corporate objective, “Enrich our life with Laser technology”
Today, we proudly announce that DS-Audio Optical Cartridge is ready to enrich your audio life. So, we may be with you every day!



2,DS Audio Factory visit  (from [analog] magazine vol,44)


Digital Stream Corporation (DSC) is located in a quiet residential area of Sagami-Ono, Kanagawa Prefecture. It is about 10 minutes’ walk from Sagami-Ono station in Odakyu-line. DSC may sound unfamiliar to the most of the readers. This is the company making state-of-art Laser Optical devices, not speaking of CD/DVD/Blu-ray standard laser optical heads.
The company was founded in 1989, as R&D Company in the advanced laser optics field, and became famous in the industry.
Moment you step into the lobby, you will immediately notice that this company has been dedicated to develop optical products through their products display.
Jointly developed products with Microsoft along fill the display table, with various technology prizes received in the past.



Mr. Tetsuji Aoyagi, President of Digital stream, graduated from American University, founded Digital Stream Corporation with his strong desire to make his contribution the world with the advanced technology.
That has been the core stream of this company, developing the cutting edge products, and has been leading the market. Their cornerstone products have been the optical pickup heads for the disc evaluation system.
DSC has lead the optical disc market as the extremely accurate laser optics to guarantee the disc compatibility and quality tests. It is very interesting to know this background, where DSC is at the edge of highly advanced digital field (CDàDVDàBlu-ray), and yet they are deeply involved in the classical analog world today.

It is my simple question. Why Analog cartridge now?  What made them develop Analog Cartridge? I threw those questions to Mr. Tetsuaki (Aki) Aoyagi, DS Audio representative and the son of founder. Aki is 27 years old and very seldom you see such a young leader in the analog industry. After talking with Aki, I understood Aki’s belief and DS Audio reflects his philosophy strongly.
Aki sees Today’s music industry puts much value in Easiness and simplicity. It is great that you can carry thousands of music in your pocket. Yet, is this what we are looking for? Is this the right yardstick we measure music? What about our emotions and feelings? Aki knows that we need another yardstick for music that appeals to your feelings. Searching for his music yardstick in different media, Analog record is the one to meet
his feelings.
So, analog is his yardstick. Countless records in the world are ‘human history’ and our treasure. Those must be passed on to the next generations. Aki, therefore, decided to contribute his time to set a new yardstick in Analog record market, wishing to put a new light on our music heritage with the optical cartridge.
Talking with Aki, I felt his strongpassion and moved by his deep thoughts.

Handmade with state-of-art technology and master skills
2nd floor of DSC is about 200, and one corner is fully designated to the optical cartridge production. Contrary to my expectation, I was amazed by their complete ‘handmade’ processes.
Among sophisticated testers and optical equipment, each cartridge is made by skilled engineers with well-designed jigs. In this day and age, the majority of manufacturers are outsourcing parts. Whereas in DS Audio, Electric components are hand soldered by the experienced engineers.
Their concern can be seen on the backside of the printed circuit board in Equalizer. The legs of components are twisted onto the extra wiring and soldered.
This is because DSAudio believes 35μcupper membrane is not good enough for the audio signals to flow. Backing up the ground line reduces the impedance of the circuit. I have never seen such a detailed concern in any other audio makers. I asked Aki that this is too much work process, how can you make volume
production? He replied, “This is our way and our concern. Quality comes first.”No argument here.

Cartridge production goes with 5 pcs a lot. After each process, over-night aging is done. Aki explains that this is an important process to take out any assembly stress on the parts.
This is the know-how from sub-micron laser optics assembly.
Those engineers are highly experienced and skilled, but those time consuming assembly processes result
production volume of two cartridges a day.
Aki showed me the optical adjustment process, which is the most important step in the assembly. Two oscilloscopes are used and each displays 4-channel voltage signals from the photo detector.
Balancing out those outputs is truly the master work.
Adjusted cartridge is then tested and goes to the data measurement step. Once again, this completed
cartridge is put into aging, and data is collected once again for the comparison. Before packaging, the cartridge is played with 5 distinct recordsfor the sound quality, together with Test records.  


It was interesting when Aki showed me the adjustment step. Even I could not see any off set of the parts under the microscope, I could hear the clear difference in the played back sounds. It isa superb craftsmanship, I must add.
All for the music, merging Advanced technology and Craftsmanship
This visit was an eye-opening experiencefor me.
Most advanced technology is harmoniously merged with master craftsmanship of experienced engineers.
Their optical cartridge is manufactured by their love and care for the analog music.
I have visited all kinds of manufacturers in this market, and never seen anyone who is taking such a
time-consuming assembly method like DS Audio. I am sure that the production cost should be much higher than what you imagine.
But, as Aki pointed out, “it is all for the love and care of our Analog heritage. Nothing worth more than this.
We need the best.”


I began to understand why DS Audio made such a big impact in the market.
Through their products, you can feel their “Feeling” and “Love” in analog music. Just hear for yourself. You too
understand what I mean.
I am happy to know that the company like DS Audio
is coming into Analog market. It is my feeling that DS Audio will surely bring
us a new stream of analog music as Renaissance of Analog. I will keep my eyes on this company.

released June 15th,2014 in Japan