SPL Phonitor x - Review Introduction This will be a summary or TL;DR; version of my full review. - if you want more information then I have a much more comprehensive and detailed full review posted on the main headphone.com site. That “full” review includes more detailed impressions on how the unit sounds, it’s features and how they work (in particular the “Matrix” feature), coverage of the optional DAC module and some thoughts on how it works with other gear. The unit I am reviewing is on kind loan from “Headphone.com” for audition/review purposes. -- The “SPL Phonitor x” is a premium, feature-rich, headphone amplifier and pre-amp, billed as having features and performance that lend it equal facility in professional/studio settings as well as in the role of an audiophile headphone system. The unit provides both balanced and single-ended source inputs and headphone outputs. A configurable cross-feed/speaker simulation “Matrix” feature, a granular balance/stereo/mono control, VU meters with configurable sensitivity and enough power to drive almost any headphone with power to spare. Options In addition to “classic black”, the Phonitor x can also be had (along with the rest of the matching line of SPL components), in two additional colors … a classy looking silver and, perhaps my (guilty) favorite, a metallic red finish. An optional DAC module, the “DAC192” can be added to the unit (at time of purchase) for all-in-one operation. The unit I am reviewing is equipped with this module, details and impressions for which are contained in the full review. Build The Phonitor x has a very solid feel to it; all of the switchgear is wonderfully tactile and engages firmly and positively with a satisfyingly solid “thunk”. The large, central, illuminated volume dial is buttery-smooth. All sockets mate solidly with both input and headphone connectors. Labels are clear and concise, with the functions they indicate being entirely unambiguous. The overall impression is that this is a very high-quality and entirely “premium” device. Sound The $2,499 question is, of course, “How does the SPL Phonitor x sound?” In a word … fantastic! For a start it is clearly both an entirely neutral and highly transparent performer. Using a variety of sources and headphones there’s no tonal shift beyond what those components impart by themselves. How transparent? Much of my listening was performed using a Chord DAVE DAC as the source. The Phonitor x is the only solid-state amplifier I’ve paired with/compared to DAVE that does NOT result in a noticeable loss in transparency or resolution. It covers up nothing, makes excuses for nothing, and lets the source show its true colors without omission or editorialization. It is, for all intents and purposes, the proverbial “wire with gain”. Lots of gain, if you want it … There is an addictive sense of lurking power, absolutely effortless delivery and this is accompanied by an impression of “scale” to music that I’m not used to outside of either very-capable speaker systems or state-of-the-art tube-based headphone rigs. Huge dynamic swings in the most powerful musical performances don’t even begin to phase this thing, while micro-dynamic nuances are fully resolved, even when they’re occurring together. Transient response, perhaps mostly subtly exemplified by plucked strings and most vividly by rapid-fire electronic percussion is, to say the least, first class. Paired with Focal Utopia, HD800S or Abyss AB-1266 Phi, transients are lightning fast, and that remains the case with somewhat more laid back cans like the Audeze LCD-4. Listening to one of my favorite instruments, the piano, both from commercial and my own recordings (of my own instrument), illustrates a pure, unwavering tonality. No emphasis, no bias, just a pure and honest reproduction of what the unit is being fed. Treble is delightfully smooth, but without any loss of detail and maintains an excellent sense of air, space and, where called for, delivers any sparkle present in the source material - with no rough spots nor glare at all. Bass is reproduced with excellent drive, slam and control and yet retains its texture. Tunes played in the lowest bass registers are ably communicated. Some of this is no doubt due to the significant available power, combined with larger than typical voltage drive. Both upper and lower registers blend perfectly, seamlessly, into a fully detailed and present midrange. Once again I was struck by how transparent the performance of the Phonitor x was, even compared to the direct outputs of the DACs I’ve been feeding it with. Detail and resolution are superlative; where brush strokes on cymbals or drum-skins are so well rendered that you can hear when the wire bundle is split or part of it clips the rim of the drum head. The inadvertent twisting of a bow as a violinist seems to shift the hold mid-note, minor utterances, odd, tiny, shifts in a vocalist’s tone, changes in the depth and pace of the artists breathing, environmental noises (chairs moving, pages turning in music, other sounds common to live recordings) are all clearly audible(fn). Complex layering is easy to hear through and excellent separation make focusing on a given instrument, or voice, amazingly easy … either spatially (especially with the right headphones and the “Matrix” function in play) or by being able to isolate that one performer/instrument via its sound and how it is being played. If you want to pick a mix apart, or focus on part of an orchestra, the Phonitor x is an excellent tool. Overall, music is portrayed with a distinct sense of “substance” and notes carry an interesting feeling of “weight”, despite the result never feeling anything other than realistic, natural and transparent. This is set against a dead-silent, carbon-black, background. At no point, in normal operation, was the background anything other than completely silent. And it is, perhaps, in part due to the absolute void against which the music is delivered that results in the presentation being one of absolute clarity and vividity. Summary Simply put, the SPL Phonitor x is the best sounding solid-state headphone amplifier I’ve heard. It maintains a neutral, accurate, extremely transparent rendering while providing ample drive to the most demanding headphones I own. It yields a huge sense of scale and power with effortless delivery, has excellent tonality AND tonal weight, transient response is superb and it plies it’s trade against a dead-silent, void-black, background. Its features, and sonic performance, make it easy to integrate into studio scenarios and still able to satisfy audiophile sensibilities. The optional DAC module is a useful convenience feature, but I’d reserve it’s use for monitoring purposes - when listening for pleasure I would be looking elsewhere for a source. If you’re looking at high-end headphone amplification, then the SPL Phonitor x really deserves to be on your audition list. I am sufficiently enamored with the Phonitor x that I have decided to buy one; which is the highest recommendation I can give any component. It'll replace the iFi Pro iCAN that I was previously using for solid-state duties in my primary rig.