my name is Ralph Stens. I was born in 1959 in Germany. At the tender age of 15, the audiophile bacillus infected me and has never let go of me since. During my studies – I received a university degree in electrical engineering / electronics & high frequency techniques – I started to develop my own circuits for my hobby.
Throughout my professional career, I have been developing mainly analogue and digital circuits around industrial measurement techniques and laboratory equipment. Over the years, a wealth of experience has accumulated here. An advantage for my hobby is that the tasks of measurement technology and audiophile circuitry are very similar in many areas.
But why do I then engage myself with Pass Labs circuitry?
From my point of view as a professional electronics developer the SUSY topology is the best circuit technology for amplifiers in audio design. Over the years this has been confirmed for me by listening comparisons on various high-quality audio systems. So if there is an – at least in my opinion – optimal amplifier technology, it makes more sense to work with this circuit technology than to try completely new developments.
Ultimately, I never make 100% replicas. A company like Pass Labs is subject to commercial constraints that the homebuilder is not aware of. For the individual pieces, especially for your own use, you can develop all you can design and get the best out of the design’s for yourself.
For this reason, on this homepage you will find descriptions of audio circuits which I have designed myself, but also reproductions where the core of the circuit is built on devices from Pass Labs.
Philosophy / Design Specifications
It is my firm conviction that a kind of philosophy or, to put it more simply, a personal opinion about the technical and acoustic conditions is needed to achieve a really good audio transmission system over the years.
Whoever constantly tries something else will remain an eternal seeker.
I’ve heard the best equipment from people who have been dealing with this topic for decades and have formed their own clear opinion. One notices that these audio systems have been optimized step by step over many years.
The best audio equipment you can find at the do-it-yourselfers.
A statement that should not come from anyone less than Dieter Burmester. It is also my experience. This is not because this group of audio lovers is particularly smarter, but because the above-mentioned applies to them in a very special way. They care for and maintain their systems and usually continue to develop them over their entire lives.
So what are my design basics? The answer is of course to be found on the entire homepage, but I try to bring it once here on the essential points. But the most important thing is:
They are my rules and I make no claim to universality!
- No dogmatic approach to the selection of active components. You can build excellent devices with tubes, bipolar transistors and/or FETs. However, I personally do not like working with tubes.
- Balanced circuitry is preferable to unbalanced circuitry. If possible, the circuits should be super-symmetrical.
- I prefer discrete stages with higher operating voltage to stages with integrated operational amplifiers, even though the VV6 has impressively proven that this approach is not really necessary.
- The power supply of an audio device is at least as important as the actual audio circuitry. Here, too, I prefer discrete regulations to integrated solutions.
- A power supply unit should always be oversized and be able to supply the required current with ease.
- Where it is technically possible and reasonable I build power supplies for stereo applications in dual mono version. As the only compromise I sometimes take a common transformer – usually for space reasons. But then, of course, with separate windings.
- In mixed systems – i.e. with analog and digital circuit parts – the grounding must be built up consistently separately. Only at the earth connection do I bring the potentials together in a targeted manner.
- Since 1980 the topic loudspeaker – at least in the frequency range from approx. 100Hz upwards – is finished for me. I haven’t heard anything better than the 57 Stacked Quad powered by a potent super-symmetrical power amp yet.
- Before you think about cables you should take care of the room acoustics. The progress to be made here is much greater.
- Most systems in a normal rectangular living room without any room correction measures can actually not be listened to seriously. I am aware that I am offending many people with this statement, but anyone who has taken appropriate corrective measures knows exactly what I am writing about here – before 2014 I would have considered such claims to be just crazy.