Introduction

In this month's newsletter, we feature an online interview that Audio Note Singapore had with Mr Yamada of Zanden Audio (Japan). He talks about the Zanden product development. We would like to thank Mr Yamada for this opportunity.

We would also like to announce that our website has included new audio equipment from Portal Audio (amplifiers) and ASCENDO (speakers).

Interview With Mr. Kazutoshi Yamada of Zanden Audio

The following is an interview with the highly esteemed Kazutoshi Yamada of Zanden Audio fame. He is the man behind one of the hottest super high-end audio brands in the industry, and designer of the award-winning Model 5000 tube DAC and Model 1000 tube phono stage. Some of his other products include the elegantly beautiful Model 7000 amplifier that sets new standards in the pure Class A Single-Ended genre, and the new top-of-the-line Model 9500 monoblock that is taking America by storm at this moment.

Mr. Yamada, when did you first start Zanden, and what were your goals at that time?

I started Zanden 24 years ago, when I was 27 years old. At that time there was only analog. My goal was to realize true live sound from LP records. I found one solution, which I am using in the Model 1000 phono stage and Model 5000 DAC. This was the use of a fixed impedance filter technique.

I graduated from Osaka Prefecture University. My major was electronic communication engineering. I have the experience of more than 500 live music concerts as a coordinator. Therefore, I have a lot of experience listening to live music. I like classical music, especially Bach. I also like Jazz and world traditional music.

It is easy to get high power from a pentode circuit compared to a triode circuit. However, I don't think the negative feedback circuit is the best choice for audio electronics, and pentode tube circuits inevitably need it. We must use a triode tube circuit if we want to avoid using any negative feedback. Moreover, we can use a permalloy core output transformer for better sound quality. And while the triode circuit gets less power than a pentode tube circuit, we can compensate by using the 845 triode tube to get higher power output.

Are there any design aspect or parts selection in your products that are unique to Zanden? Is this the reason why you can achieve the special Zanden sound?

I already have 6 patents and a patent pending technology regarding analog filters for digital audio. I design all my amplifiers with these technologies and some other very unique ideas. Some examples:

• I use a non-traditional, unique fixed bias for tube circuits whenever possible. I believe in minimizing the number of capacitors in the circuit. I always use a rectifier tube to produce the minus bias. I almost always use polypropylene signal capacitors.
• I invented some useful current-regulated circuits and have applied them to all of Zanden's amplifiers.

Your Model 5000 MK3 DAC has achieved remarkable worldwide success, and even received some highly coveted awards from major magazines. Is this due to the 1x oversampling technology that is used in the DAC, or are there other factors?

The 1x oversampling technology is certainly an important factor. The DAC also has some other unique and important technologies. One of these is the currently patent pending Zanden analog filter that reduces sampling noise. Its phase shift characteristic is only about 10 degrees at 20kHz. Also this filter is a fixed impedance type and constructed as a passive device. It consists only of coils, capacitors and resisters.

So this filter acts as a straight wire within the music signal frequency range (20Hz to 20kHz). The tube amp circuit is unique and unlike any other manufacturer's circuit.

Regarding the latest Model 5000MK3, this DAC uses a very effective RF noise absorption material, that was invented in Japan and not used by other manufacturers in the audio industry.

I have been studying about the influence of RF noise and its relation to sound quality for 2 years. Thanks to this research, I have reached some important results regarding RF noise, and I am going to release some products benefiting from it very soon.

Yes, I am developing a very high quality top-loading CD transport right now. This transport will be compatible not only with the Zanden DAC but also every other DAC. The final sales product will have 2 versions. While the cosmetics are the same, the clock circuit and accuracy are different. The top model is really exceptional because it has a clock oscillator, which is about 10,000 times more accurate than other famous hi-end transports. (The entry-level unit is fully upgradeable to the top model).

Both models have a special design that solves some of the basic problems of CD pick-up mechanisms and a special construction, which reduces the negative effects of RF noise. I am designing the main transport unit and power supply units separately. The CD mechanism is the Philips CDM12 PRO2 with some modifications.

I know that a high quality line stage amplifier (or preamp) is needed by the end-user. Therefore, I am working to release one as soon as possible.

Currently, I have only a prototype version. I intend to focus on it after releasing the Zanden transport. I have already finished developing a new digital cable for use between the digital transport and DAC. This will incorporate the same RF shielding materials used in the Model 5000 MK3.

Also I am developing some useful accessories to improve the sound quality of various components. More details of this will be released at a later date.

Lastly, I am very interested in high-efficiency speaker systems like the horn designs from Avantgarde Acoustic.

I would like to design a special low noise amplifier for them next year.

All information in this abridged electronic newsletter is valid at the stated date at the top of this newsletter and all information is correct at the time of its release. Some information may not be relevant at the current time, please check with us for any queries regarding this newsletter. All product names and trademarks are the properties of their respective owners.
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