Honda-san's iPhone Adventure
Well, I have to introduce Honda-san to the readers of Jeff’s Place. I have known Honda-san, Mr. Jun Honda, personally for almost a quarter of a century. We were both engineers working in the same company, Pioneer, when he was a young, up-and-coming amplifier engineer, but meanwhile I was already in charge of the DVD player engineering department.
Normally, it would be an extremely rare case for two engineers in the same company, who are 18 years apart in age, to become close friends. However, two facts that may be called mysterious guidance led to our long relationship: I found that we had similar tastes in music, and he took a great interest in my hobby of tube amplifiers.
What I still remember vividly is that one of the analog LPs we enjoyed together using my Altec 414A and Onken horn speakers was a masterpiece of all jazz masterpieces, “Sarah Vaughan with Clifford Brown”.
In the late 1990s, Honda-san was involved in the development of the next generation of extremely high-efficiency amplifiers, commonly referred to as digital amplifiers, which were a hot topic in the audio industry at the time.
However, in order to develop an amplifier with a completely different operating principle than before, it was first necessary to simultaneously develop the device and the circuit.
At that time, Honda-san, a genius engineer, might have already had the outline of circuit design, a PWM class D amplifier circuit, drawn in his mind.
His strong desire and passion to develop these devices led him to move to Los Angeles in the USA, where he joined International Rectifier.
Of course, his wife and three lovely children were also with him on the move. When I was informed of his decision in 2001, I myself was working alone in Semarang, Indonesia, far away from Japan, and I was facing the various challenges and difficulties of an unfamiliar place.
Therefore, I felt even more deeply how much risk he was taking with his decision to move to the USA, and I had a deep respect for his unshakable courage and his wife's strong trust in him, and I prayed for the best of their luck.
It was five years later that Honda-san and I rekindled our friendship on my business trip to Los Angeles.
The Christmas season in 2006 already had started, and at a lovely seaside restaurant in Redondo Beach, with a cool and pleasant breeze, we had a lot of fun talking as the night went on and continued until the restaurant closed.
While we were talking Honda-san introduced me to IRAUDAMP 4. Honda-san had just completed its development, and I was able to get this reference design of the latest Class D amplifier from him.
My involvement with IRAUDAMP 4 was from early 2007, in other words, my quest to realize its full potential in pursuit of the ultimate sound quality, continued for over 15 years.
Now, my improved IRAUDAMP 4 has reached a level that is almost comparable to the sound quality of my WE 310A driven PX25A (DA30) SET, which I have been improving for over half a century in terms of its musical expressiveness, listening from every angle.
There is a definite fact that the sound quality of the extremely simple single-ended amplifier using a rare direct-heated triode that I have completely modified, and the latest Class D amplifier built with the highest quality parts is extremely similar.
This would be the proof that the device and circuit design of Class D amplifier that Honda-san developed over 15 years ago was truly innovative and had incredible potential.
Anyways, Honda-san has continued to be an industry authority on Class D amplifier device development, holding a key position as the Senior Principal Engineer of Class D Audio Systems at Infineon Technologies Americas Corp., which took over International Rectifier.
What I would like to emphasize here is that although Honda-san was such a genius engineer, he doesn't have any arrogance, and has a humble, warm, and open personality that could only be expected of someone who has lived a truly blessed life.
Honda-san is a truly likable person with a sound and respectful personality.
I've felt for a long time that great audio equipment, and splendid parts, such as vintage vacuum tubes, reflect the true personalities of the engineers who developed them.
In this sense the IRAUDAMP 4 embodies not only Honda-san's exceptional technical ability, but also his strong passion and desire to provide the world with extremely highly efficient devices that are boasting remarkable musicality.
I think that I have confirmed this fact as I have spent over 15 years trying to unleash the full potential of IRAUDAMP 4.
Well, I have been introducing Honda-san or Jun-san for a pretty long time, but what I would like to talk about in this chapter is how Honda-san, who is an active engineer and a big fan of Spotify, a music steaming service, became actively involved in our iPhone Adventure.
Actually, I traveled to the United States from the end of September, to early October 2022, when the spread of the coronavirus had subsided.
The purpose of the trip was twofold. I met with Honda-san again for the first time in a while, and we enjoyed the scenery of Southern California from Los Angeles to San Diego.
The other part of my trip was to fly to Texas to visit Alan-san, and do some upgrades to the sound quality of his PX25A mono SETs.
Regarding this on-site version upgrade, I have already shared this in Part 5 and Part 6 with Jeff’s Place readers.
Well, thankfully, even though Honda-san was busy, he was able to spend time with me for most of the three days. Of course, in the car and along the way, we talked and shared the subtleties of each other's lives, and had a truly blessed and precious time with wonderful extraordinary experiences.
After I returned to Japan, I wanted to repay Honda-san's kindness and hospitality in some way. I came up with idea to present Honda-san with a Douk Audio U4, which Alan was already very happy with, and hoped Honda-san would also enjoy our iPhone Adventure.
However, we were all very excited to hear Honda-san's evaluation of the Douk Audio U4 for our iPhone Adventure, and also to my friends in Japan, including Nishikawa-san, Kajiwara-san, and Kato-san.
I sent a new Douk Audio U4 with a NOS WE 396A vacuum tube to Honda-san by EMS. The sound of the WE 396A should be a great match with the sound of the JBL4320, which Honda-san has been using for a long time. I assumed that it would fit perfectly with his music and sound tastes. That was at the end of October 2022.
Here are the two email responses I received from Honda-san:
“This is only my very first impression, but the Douk Audio U4 is very good! First, I listened to the sound using the included Russian tube. My speakers are JBL4320, and the amplifier is the Gallium Nitride version of AMP4."
"In just one listening, I was impressed that it produced a very fresh, three-dimensional sound image. I also felt it has a lot of potential. The feeling that the sound is released without stress must be unique to a DAC that does not undergo digital processing, and it is very good."
"I also appreciate the good sound quality of Bluetooth 5.0. I've listened to several genres of music from my iPhone, and they all come alive. I compared it with the USB DAC I have, a Delta Sigma DAC."
"The U4 offers a more vivid expression and enjoyable music. Yes, the huge sound space of Miles Davis' Kind of Blue makes me feel good. The bass is firmly separated from the speaker. Next, I will switch to Western Electric tube and report back. Thank you very much for the wonderful gift.”
The next day, Honda-san expressed his excitement as follows:
“I just installed the WE 396A. The Western Electric sound is too amazing! That's a huge difference! My favorite is Western Electric sound! Wow, I can say only amazing. Thank you very much for giving me such a wonderful experience. I will also report the details as I listen more closely.”
Honda-san became the latest kindred spirit added to our iPhone Adventure.
Honda-san also highly praised the lively sound of the Douk Audio U4 with the vintage NOS RCA 5670, and used it as a main music source device in a demo room of Infineon Technologies’ new Class D solution at CES 2023 (at The Venetian Resort in Las Vegas) just two month later (above).
Naturally, both customers and staff were iPhone users, so the sound demonstration was very well received.
Furthermore, Honda-san conducted a circuit analysis of the final stage circuit diagram of the Douk Audio U4 for me (above), and when I had a chance to look at his circuit diagram, I was led on a new adventure into the Improved U4.
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