The David Berning Quadrature Z Mono Power Amplifiers

Stretching Your Horizons...

I think the Beatles said it best when they sang, “Oh that magic feeling, nowhere to go”. And it is true, for me anyway, that having absolutely nothing to do and nowhere to go is indeed magical. I have never been able to understand those people who are always going on about how they just HAVE to be doing something or they would go mad. The idea that, upon waking, the day stretches before me, is entirely my own and requires no contact with the outside world is blissful indeed. Sometimes I can spend hours with my guitars or effects pedals, simply playing the day away.

But recently things have changed. Whereas I would normally begin my listening sometime during the early afternoon, increasingly often I have found myself perched on the sofa as early as 8.30 AM intrigued by some musical fascination. And of late I have often stayed there for hours on end, rising only to change the music or make tea. I have begun to realise that, somewhere deep within my previous appalling slovenliness, there was a kind of routine. An order of things that is probably linked to a kind of deeply anal Virgoan fastidiousness that is completely out of my control (although RG would say it’s because I am just a recluse at heart). Fortunately I will not have to seek help for my present condition. It will pass quite naturally, for I have realized who is responsible; I point the finger across the Atlantic at David Berning of Maryland in the USA, as it is his monobloc amplifiers that have had me totally hooked and continually capture my musical fascination in a way that so few products ever have.

For days before sitting down to write any review I try to format the task stretching before me in my head. What am I going to say and how will I say it? But, every now and again, when an absolutely brilliant piece of audio hardware comes along I can’t help fantasising about submitting a piece that has the name of the component and just a few words beneath which say something like “Totally amazing amplifier, if you have the system for it and can afford it, then buy it”. It’s succinct, to the point and encapsulates how I feel, but it doesn’t give you the full story does it? In fact it will be very difficult for me to give you anything other than a very partial glimpse of the technology behind these amplifiers and the steps that David Berning has taken to address the well-known limitations associated with OTL amplifiers. I am no amplifier designer and have little comprehension of the finer points of audio design and even less where valves are concerned. But what I will say is that as humans, we like to compartmentalize and as audio and music lovers we also have a strong tendency to fit various types of component into neat little slots. Hence the widely held belief that solid-state amplifiers are fast, a little lean but have grip and control. Valve amplifiers on the other hand, are warm and more colourful, but slow and a bit soft. If you are even a general subscriber to these stereotypes (no pun intended) then time spent with David Berning’s amplifiers will be the audio equivalent of a cattle-prod in the nether regions because, despite being an all-valve design, and OTL to boot, the Quadrature Z amplifiers will shake your preconceptions to the core*. They’ll open your ears to the sheer beauty of music. Experience them and you’ll not give a hoot whether they are valve, solid-state or made from recycled washing machines. With these amplifiers the music is the message and the method of delivery is awesome.

The absence of output transformers and the fact that they eschew battleship build too, makes these amplifiers deceptively light in weight; no “hewn from solid billet” casework here. The facia is a simple alloy plate with extensive grilles to cover the innards. So if you judge by appearance alone you might well wonder just where all the money went. Internally though, the amplifiers are superbly constructed and point-to point wired. You just know that this is no mass produced component. As I mentioned before, the solutions arrived at have eliminated the problems usually associated with OTL designs, yet have preserved all those things that commend them, such as their astonishing openness and transparency. And valve life is very impressive too, at a projected 20,000 hours.

The Quadrature Z amplifiers utilize embedded Stillpoints resonance control devices in each of their four feet, but you can take this a stage further by bolting a four-legged Stillpoints Component Stand to each amp in place of Mini Inverse Riser feet to give a total of eight resonance control devices for each mono amplifier – a very smart move indeed. The same importer deals with both products and I strongly suggest that you factor in the cost of this installation when taking delivery (£1590pr.). There are also other requirements that simply must be met if you are really going to hear what these amplifiers are capable of. These begin at the mains socket on the wall and include everything from the equipment supports to the hardware. Finding a pre-amplifier of sufficient quality is not going to be easy and you can probably count the candidates on the fingers of one hand. Fortunately the Lyra Connoisseur 4.2L SE works absolutely superbly with the Bernings. Your source too needs to be impeccable, as does the cable loom. I used the Naim CD 555 and the Burmester CD 001, while the cabling was Nordost Odin for both interconnects and speaker cables, with Valhalla, Quantum and Thor for the mains. Everything was isolated on the Stillpoints ESS rack. For speakers I used both the JMLabs Micro Utopia Be and the exceptional Eben C1 (reviewed elsewhere in this issue). I would have enjoyed using them in a wider bandwidth system, but fear not, RG will be doing that in the next issue.