How To

Ken Ishiwata, a man and his listening room


Ken Ishiwata’s listening room is hidden in the basement of an innocuous looking office building in Eindhoven, you would barely guess that this was Marantz’s European headquarters let alone the lair of the guru behind KI signature and SE products for the last thirty years. Yet it’s a magnificent room that took eight months and €160,000 to create back in 2007 (and no, the rear wall is not gold as the picture suggests!). It was designed to provide an even frequency response without having a dead sound, it would have been easier to have installed a studio control room style damping, but in Ishiwata’s opinion this kills the music, so he used a range of different diffusion techniques to give the room life without introducing direct internal reflections. It’s a cross between a concert hall and a control room with a 22ms reverberation time and a floor area approaching 50 square metres (over 500 square foot). It works extremely well with the Boston Acoustics M350 speakers he designed in cooperation with Karl Heinz Fink, allowing them to deliver remarkable imaging, bass extension and power for what is a fairly compact design.

kens room

Ken played a variety of tracks with his Macbook Pro hooked up to the USB input of the Marantz SA-14S1 SE CD/SACD player and DAC that is being launched in August. As is the partnering PM-14S1 SE amplifier that was driving the Bostons to remarkable effect for a sub £2,000 integrated. These two products were unveiled at the High End in Munich but the circumstances there were far from conducive to appreciating the finer qualities of the latest addition to the Special Edition series. The first of which appeared in 1986 when Marantz realised that their four times oversampling, 14-bit CD-45 had been made effectively obsolete by the introduction of 16-bit players to the market. With 2000 units in the UK warehouse they were considering a serious price cut to sell them off when Ishiwata suggested that he modify the design. He did this and gave it to David Prakel on Hi-Fi Answers who was blown away and wrote as much in his review. Two weeks later they were all sold, oh to have been a reviewer in those heady times!
Ken demonstrated the SA-14S1 SE using JRiver on a Macbook Pro because of the ease with which you can play different tracks and the access to high resolution material the approach provides. It also served to demonstrate the quality of the USB receiver on this machine, which is the same isolated type used on the SA-11 S3.

KI himself V

Ken is naturally up to speed on computer audio and mentioned a couple of tricks that I intend to try, one of which was that defragging the hard drive on which you store your music is highly beneficial. He says that there is some Japanese software that’s great and will hopefully supply more detail in the near future. He also recommends setting up the PC to buffer music stored on an attached drive, especially if the PC has an SSD drive. He demonstrated the effectiveness of this set up with a mix of classic and lesser known tracks, of which that old hi-fi favourite Cantate Domino (SACD, Proprius) was among the most remarkable. The sense of a choir in the room was palpable, the imaging quite extraordinary especially given that I was sitting off centre. Ken sets up the Bostons so that their axes cross in front of the listener, which is a known technique for producing a wide sweet spot, but usually room reflections undermine its effectiveness. In this room you could close your eyes and hear all the voices spread across the soundstage.

An interesting point was made regarding modern DAC chips, Ken pointed out that all of them are delta-sigma or one bit devices, in other words PCM with its 16 or 24 bit depth is always converted to one bit. This does not happen with ladder DACs, which is one reason why they sound so good, but makes a good case for using DSD which is already one bit. The Marantz player/DAC can run at up to DSD128 or 24/192 but KI is of the opinion that CD rips are not far behind high resolution formats and played a number of them to make his point. He also mentioned that 24-bits gives you over 140dB of dynamic range, something that no amplifier and speaker combination is able to turn into real world sound. Ken’s enthusiasm for DSD has lead to him archiving his vinyl to that format using a Korg recorder.

kens system

The standard 14 series components started life 18months ago and for his SE versions (above in black) Ken has stiffened the chassis with a heavier top lid and better feet as well as adding damping to minimise vibration. The power transistors have copper caps to minimise intermodulation between devices caused by heatsink vibration and the capacitors in the power supply of the amplifier are upgraded to Elko types. Ken has also added shorting plugs to the phono input and the coaxial digital inputs on the CD/DAC, which makes me think that such things require investigation. Those are all the mods that he is prepared to divulge, the rest are the guru’s secret tweaks.
It’s interesting to see how much attention KI is paying to vibration control, this is an area where relatively few manufacturers appear to be making an effort, yet its effects can be easily demonstrated with a support system that provides genuine isolation. What would the room sound like with some of that in it I wonder?

Ken talked about a variety of things after the listening session, including Mark Levinson’s ability to sell his name, again, this time to Lexus, by putting ‘Mr’ in front of it, Harman must love that! And John Curl who designed the first Levinson preamplifier, the JC-1, and went on to do some remarkable work in our field yet never attained anything like the celebrity status of Mr Mark Levinson, perhaps that’s why he called his own company Vendetta Research. All in all it was a fascinating glimpse into the world of a man who brought tweaking to mainstream audio. Surprisingly few large brands have ambassadors like Ken Ishiwata, a man who is dedicated to making great sound systems available at sensible prices, long may he reign.
The SA-14S1 SE and PM-14S1 SE will be available in September for £1,799 apiece.

Jason Kennedy



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