The new DC4 regulator design uses the very best components – we use a full set of Vishay Z-foil “naked” resistors for the regulator section, and extremely low noise resistors for the (non-critical) CX section and for one filter network of the regulator itself. We also now use Vishay bulk film capacitors for all decoupling duties, as well as some very special Audio Note KAISEI capacitors for all the important regulator module capacitors. These are a relatively new capacitor, designed by the same team behind the legendary Black Gate capacitors. The CX module section uses the same Nichicon FG “Fine Gold” capacitors as the DC3 design, as we found that the KAISEI capacitors made no noticeable difference here.
It is also important to note that the regulation module is a series design, which delivers double stage regulation for 8-10 times reduction in noise, compared to a single-stage – similar to the approach applied by CH Precision in their X1 power supply. The heavily shielded power transformer is a 400VA unit. By way of comparison, the transformer in the Neodio HQA power amplifier is 300VA. And they weren’t kidding about the lack of damping: the lid on the review unit clanks like a sound effect from a scary movie. I cured the problem by simply placing a medium-sized HRS Damping Plate on top of the casework, but I’m told that current production includes damping pads applied internally and mechanical measures to cure the issue.
The Arturo Benedetti Michelangeli/Beethoven 1st Piano Concerto recording (with Giulini and the Wiener Symphoniker) is, in its own way, another benchmark. A wonderful, concert performance, it really captures the essence of live classical music, its complexity, scale, expressive range, delicacy and dynamic range. Not that you’d know all that playing the DSD 64 file from the Nucleus powered by the stock supply. The presentation is ‘wall of sound’ flat, with a scattergun approach to instrumental location that doesn’t just litter the instruments randomly between the speakers, it distributes the piano with similar abandon. Colours are compressed, there’s a threshold to dynamic steps that renders them non-existent or clumsy and over bold, robbing the performance of grace and expressive range – which is quite a feat, given the inherent musical qualities of the recording. In short, it’s an experience that encapsulates all that is so often wrong with streamed music…
Substituting the Mini ARC6 DC4 power supply was musically transformational. It immediately restores the sense of space, order and atmosphere to the recording. The perspective becomes more natural in terms of proportions, depth and height, with the instruments back where I’d expect them to be. But far more important is the restoration of dynamic discrimination, expression and control. The challenge with any concerto, is balancing the output of the solo instrument (even a piano) against the power of the whole orchestra. Using the standard power supply, the recording sounds compressed, with everything equally loud, no scaling and no dynamic graduation. The piano doesn’t just match the orchestra for width, it matches it for level too! With the linear power supply, the music isn’t louder – it’s quieter. It’s quiet when it needs to be, allowing it to swell in terms of energy and density when it has to. You hear that at the micro-dynamic level, in the fluid grace and subtle changes in note weight in the piano part. You hear it in the control, constraint and direction of the orchestra in the opening, Giulini holding them down when they can clearly play so much louder. That sense of restraint is all-important to the piece, giving an air of anticipation, latent energy and leading into the lively, vivacious delicacy of the solo part. Where the standard supply reduces the pianism to almost pianola levels of mechanical rigidity, the linear supply allows the grace, articulation, pace, purpose and rhythmic expression to emerge. Listening with the standard supply, you would never know that this is perhaps the seminal recording of this key work from the classical cannon. With the Sean Jacobs supply delivering the DC, the Nucleus is able to deliver the musical goods, the performance emerging butterfly-like from the dull carapace of its switch-mode chrysalis.
