Originally from South Africa, Robert Koch now lives in Japan and his amplifiers are both made in Japan and realise many of the best aspects of ultra-specialist Japanese audio electronics. Perhaps more importantly, however, high-performance audio has been a passion for Robert from a very young age. We spoke to him about how he created Robert Koda and where the company goes from here…
How did you start out in audio?
Our family home had two music rooms, both with decent kit. By the time I was 12 or so audio quality became important to me. With the interest in audio came an interest in electronics and radio. I became a licensed radio ham as soon as legally able at 16 years old. Through the club, I was able to get a hold of plenty of technical information but as it happened our city library had all the AES (Audio Engineering Society) journals. A golden find leaving me immersed for days on end, and building huge files stacked with photocopies.
What was your first big break?
As a youngster, I was approached by a chap who wanted me to build him an Audio Research M300. I turned his offer down, but he gave me an after-school and weekend job at his high-end audio store. I spent a decade or so at that store and we were always looking for the “Holy Grail”.
My other big break was to meet Kondo San (Kondo Hiroyasu of Audio Note fame, who died in early 2006) who was kind enough to take me under his wing. I remain incredibly thankful for the opportunity and care Kondo San – and later Ashizawa San – gave me.
What did you learn from working with Kondo San?
Perseverance and patience first. Materials and technique second. Then perseverance and patience again – Completing the task you set out upon without any loss of interest or focus.
Is this why your amplifiers use both valves and solid-state as a base?
As a teenager I learned how tubes work before learning about transistors. I have always loved tubes, but I have come to better understand their inherent limitations and fields of usefulness. On the other hand, I have learned how to better harness semi-conductors in such a way that mitigates their (mostly) soluble flaws. So, it’s a natural flow to follow what can lead to the desired result.
Your products are minimalist yet use balanced and single-ended inputs and outputs. Why?
A pre-amplifier needs to be useful in a number of settings. Some power amplifiers are best run with a single-ended input, others not. The same goes for source components. If there is no or at least very little sacrifice a pre-amplifier should be able to support all these conditions unless specified for a particular niche. In the case of K-15 there is no sacrifice but there is added cost since in our application at least the volume control becomes twice the monster…
Why are your preamplifiers low gain?
It’s all in the pursuit of ‘the purest signal path’! I tried passive pre-amps and found that even though greater voltage gain was not required to achieve a desirable listening volume, there was a definite collapse in sound quality as compared to a decent active pre-amp. Our pre-amps are built with sufficient gain (x2.5) to reach suitable volume even on older digital mastering, and our pre-amps offer loads of power gain. For example, the K-15 might consume 80µW from the source while delivering 27,000µW into a load.
What is the secret to your amplifiers’ absence of sonic signature?
“Dynamic simplicity” is a strong theme and key word in our designs. Music is in a constant state of flux and in order not to displace this delicate time and amplitude relationship we need inherently stable electronics that does not introduce additional moving parameters. Every aspect of the design needs to be ‘sorted.’ For example, a Class A/B output stage would place a music/loudspeaker related shifting load on the power supply and if the power supply was imperfect, time shifted voltage fluctuations could influence other parts of the amplifier resulting in a corrupted outcome… Quite the opposite of our vision of “Dynamic simplicity”.