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I'll describe my experience with the C03 over the past three months in the context of two radically different sounding systems yet which differ only in their choice of speakers. Starting with my long-time FJ OM reference -- rich and dense, slightly rolled off on top, slightly loose at the bottom -- driven by the transparent and unflappable Genesis GR360 + MDHR, the addition of the C03 was nothing short of revelatory.

If the Accustic Arts Preamp I Mk3 shines with its comfort and warm and sunny disposition, the C03 amazes by its transparency and tonal accuracy - very VRE-1 in its presentation. The strength of the C03 is without doubt the ability to perfectly respect timing and transients so that each element is exactly where it belongs and does not intrude on another sonic detail unless it is supposed to. This quality retains absolute and utter control of the flow and micro fluctuations the music is made of.


But that sounds far too clinical. Antiseptic the C03 absolutely is not because it adds just enough lushness and elegance to never sound dictatorial about neutrality. The best way to convey a sense for this rare balance are circus acrobats or ballet dancers whose every movement is controlled to perfection, with nothing allowed to be out of line to ensure the coherence of the whole, yet extreme elegance arises from their perfectly orchestrated performance. I am typically more of a chaos guy than lover of strict order but on rare occasions orchestrated perfection without stiffness can yield beauty. So I fell hard for the C03's way of sorting out the music.

Everything in the C03's personality derives naturally from these qualities - a huge soundstage that reaches into the far corners of the room; precise yet not surgical imaging that allows you to discover layers and layers of instrumental complexity in recordings that had previously seemed two-dimensional; deep, controlled and detailed bass; lightning-fast transients without a hint of glare or harshness... you name it, the C03 delivers.


Admittedly the C03 is not the very best at each single musical attribute but it is the most well-rounded preamp yet to come through my system. In other words, a straight-A student. The Accustic Arts is warmer and more forgiving, the C03 retaliates with more accurate and diverse tonal hues. The German incurs a slight shift in coloration often as a result of gently blurring micro-dynamics, the Japanese offers increased saturation and micro contrasts. The McCormack VRE-1 offers greater instrumental textures and three-dimensionality that exceeds even the C03 while the latter strikes back with bass depth and control as well as greater functionality. The NAT Symmetrical from Serbia offers even denser tonal colors and more natural of imaging to which the C03 retorts again with bass prowess, utterly silent operation and its ability to preserve musicality at whisper levels.

I'll spare you a blow-by-blow description of CDs. Who wants to hear a litany of broad, deep, layered, precise, intense and engulfing? Yet in all honesty, in that first system terminating in the FJ OM speakers, I struggled to pick between the VRE-1, C03 and NAT Symmetrical. Each brought out a slightly different emphasis and feel to the music. The VRE-1 was closest to being 'not there', the NAT offered a great dose of triode magic in the treble and midrange and the C03 dynamics, bass and precision.
With speakers already dense but slightly laid back like the FJ OMs, my favorite was probably the C03 by offering the most enjoyable balance of qualities in conjunction with my GR360 amplifier. Yet the NAT at times just overwhelmed me with its midrange presence by turning voices, violins, brass instruments and cellos into a concentrate of themselves – simply superb on period instruments. The NAT is probably more saturated than strictly accurate, with the C03 in this case offering the most genuine verisimilitude of the instruments but I am not above refusing a little enhancement on occasion. When the tube-induced rush was over however, I always returned to the C03 for its extra helping of truthfulness and accuracy that never betrayed the music or its spirit.
Switching to the McIntosh MA2275's power section, my biases leaned even further towards the C03. This preamplifier was made for tube amplifiers. It marries well with solid-state (in my case class D) but shines with tube amplification by improving timing and dynamics with extremely low distortion. With the MA2275, I preferred the C03 switched to +12dB while I favored 0dB with the GR360. Gain increases bass depth (with arguably leaner bass) and transient impact. Since the GR360 really needs no help in either department, zero gain's increased finesse and even better timing precision was always my preferred choice with the Genesis amplifier.


With systems that need an influx of timing and phase accuracy, the C03 seems the preamplifier to beat. Whether paired with a superior tube amplifier or class A transistor or with speakers leaning towards the lush and riper end of the spectrum, the C03 will not disappoint. But Dr. Jekyll can have his Mr. Hyde moments when not properly matched. That's what I experienced switching to the Genesis G7.1f speakers. Those could not be farther removed from the FJ OM gestalt. Lightning-fast, extended on both ends and with bass that is deep, lean, detailed and nimble, they are top to bottom one of the most homogenous speakers where no register deviates from the neutral and fast overall aesthetic.
Using the GR360 brings into the picture an amplifier just as linear, leaving the entire responsibility for tonal enhancement and musical enrichment to the components ahead of amp and speakers. With the Esoteric X03-SE and C03, there just wasn't enough of it. Perfectly well recorded material was revealed in all its glory but anything less than perfect painfully showed its warts. Remember that there wasn't a valve in sight now and the FJ's paper and fabric drivers had been traded for low-distortion metallic transducers. In the end, this was a little too 'honest' for my tastes. When you can only enjoy 10% of your discs, you've gone too far stripping away tonal and density enhancements. But I also know that some of us look for brutal honesty in a system. If you wanted ruthlessness, this combination of gear would comply.
Don't get me wrong though, I was not blaming the C03. It's the system total that did not quite work for me; not any one given component per se. Bringing the NAT Symmetrical into the picture, everything fell back in place despite a higher noise floor to showcase even more than before the musical qualities of this triode-based design. Its added tonal density and richness, slightly less emphasized attacks and gentle midrange bloom returned a hint of humanity that the system lacked without it.

Not having received Esoteric's companion A03 amplifier for review yet, I can't comment on whether it will fulfill the tonal enhancer role when paired with the C03. The MA2275's KT88s fronted by the C03 slotted right between the other two associations by being less organic than the NAT + GR360 combination but more so than the C03 + GR360. I still preferred the NAT+GR360 perhaps because nothing drives a Genesis speaker better than a Genesis amplifier. On those aluminum + ribbon speakers, I found that association by far the most emotionally compelling particularly on voices.


Tone and texture have to come from somewhere in your system and the C03 won't add any although it won't remove any either. It can be lush in the sense that what goes in comes out the same but energized and with greater dynamic nuances, revealing the micro details your source provided without editorializing the content. I would prioritize Esoteric's preamp for systems with superior tube amplifiers and/or dense paper-driver speakers like Zu, WLM or FJ to enhance their microdynamic abilities even further but in all fairness, it deserves to be auditioned for any system if you're thinking of investing a significant amount of cash on a preamplifier. Properly matched, it is simply amazing. All in all it actually seems to be somewhat more forgiving of associated gear than the VRE-1, enhancing the performance of all amplifiers I tried it with (including the Musical Fidelity A5) whereas the McCormack showed no mercy to gear that did not share its absolute lack of distortion.