A golden age only happens in retrospect: By the time you realize you're in one, you ain't. Hell, most of us have a hard enough time deciding the winners of the past (ever been stuck in a Linn Sondek LP12 vs Micro Seki DDX-1000 debate?) so speculating on Audio futures is always a dicey proposition. All that being said, it's pretty clear to me that headphone audio is now at that brief stage where small to medium sized manufacturers can profitably produce groundbreaking products and not have to worry too much about conglomerates harvesting their technology and driving them out of business. The fact that a standard bearer headphone amp like the Cavalli Audio Liquid Gold is not made by a subdivision of Sony, Panasonic, or Pioneer testifies to the market forces that reward innovation and individual enterprise. Granted, it is true that AppleBeats is the African rhino that sustains Oxpecker birds scavenging for audiophile, um… ticks… but who worries about a little parasitism when the reward is a better headphone escape pod? What do we care if Apple sells a billion sucky iPod earbuds, when it spurs the capital and demand for the exemplars par excellence of Audeze, Sennheiser, and Stax? Sallying forth, the headphone renaissance continues for me in my discovery (with a big assist from colleague Warren Chi) of a new solid-state headphone amp, the Covalent-Audio Nucleus Headphone Amplifier-Preamp.
The first thing one notices about the Covalent-Audio Nucleus is that you sure get a lot for your $399. The two-year warranty is reassuring, but hardly seems necessary, given the sturdy aluminum chassis, high quality relay and double-sided PC board. Further enhancement is produced by Nichicon capacitors that are claimed to provide "over 30,000uF of capacitance for highly filtered and bypassed supply rails which are then regulated by precision low noise voltage regulator." Although I'm not terribly enamored with the industrial motif appearance of the Nucleus, it is a convincingly solid and impeccably clean look. More importantly, this a headphone amp/preamp for those who love the intricacies of amp design. A quick glance at the Covalent-Audio website is chock full of design and engineering information. A sampling:
"The analog inputs are selected by a high-quality relay and the signal is then routed to a RK27 ALPS Blue-Velvet volume control. One audio grade Burr-Brown monolithic FET input IC (one per channel) provides low noise, low distortion voltage gain while a discrete Class AB high current output buffer provides Nucleus' extremely capable output current drive. The Nucleus is direct coupled from input to output (no capacitors in the signal path). DC offset is kept to virtually zero by an ultra-precise DC servo which has been carefully optimized so that it's sonic footprint is non-intrusive."
And on it goes, spooling out details for diehards who live to exchange frothy rounds debating headphone amp design theory. Which works for me, actually, but even so, all you really need to know is that Covalent-Audio follows the tried and true method of using a short signal path, well made parts, and a low noise power supply to do the job. The end result is a Nucleus amp that is smooth and unerringly musical. Listening to Cat Power's "Living in Bars" from her album, The Greatest, the tremendous heft of the left hand piano chords is proof that the Covalent-Audio Nucleus is more than capable of enlivening my review pair of MrSpeakers Mad Dog Pro headphones. Clean, articulate notes are the watchwords of the Nucleus, (not surprising, given the design), and even more welcome is how warm and sweet this amp can sound in the process.
Because I do ridiculous things with my time, I spent a day listening to a variety of headphone amps and DACs, using TIDAL to play the same song over and over and over, "Baby, It's Cold Outside." I finally settled on two versions, the Nora Jones/Willie Nelson cover and the Lou Rawls/Lynne Linsey collaboration. One serious stack of solid-state and tube amps later, it is clear that the Covalent-Audio Nucleus hasn't a mean bone in its body. If you like bite and edge, you need to keep going down the road apiece, as the Nucleus sounds smooth and mellow every note it plays. The stand up bass runs were cleanly articulated, the piano and guitar chord changes could be easily discerned, and musicality as a whole is decidedly in the affirmative. When listening to a hard driving song like the Foo Fighter's "Feast or Famine," (from their excellent new album, Sonic Highways) the Nucleus implores you to crank it up and bellow along. Of course, you may not get the wide, expansive sound of some tube amps, but neither will the Nucleus make you turn down the volume to cut the glassiness when the music turns edgy. Besides, some may prefer the earnest truthfulness of the Covalent-Audio amp's representation of space. Playing the past-their-prime-but-still-skankin' live version of the Specials' "Ghost Town" (More…or Less. The Specials Live) , the Nucleus reproduced a thoroughly acceptable version of headphone room acoustics in the Mad Dog Pros.
Some of the more prominent features of the Nucleus include two inputs selectable from the front panel, a Hi/Lo gain toggle switch for 6dB or 14.6 dB gain settings, and pre-amp outputs that enable you to use the Nucleus with powered speakers or an external amp. The website gives many more technical details, for those so inclined. Although Covalent-Audio says that it will run slightly warm, if felt nice and cool to my cold-blooded touch. I should add that this amp ran 10 hours a day for weeks at a time, and never made a peep of extraneous noise or worked anything less than flawlessly. Try that with your other tube amps or solid state models at this price point. So, is this the headphone amp for you? Well, if you love a razor sharp sound that bears all and takes no prisoners, then probably not. Similarly, if you're looking for that tube amp sound, with all of its benefits and imperfections, than the Nucleus is not really the one to choose, either. But if you like a sound that is warmish, yet still revealing, and always fun to listen to, you can't go wrong with the Covalent-Audio Nucleus.
Covalent-Audio Nucleus Headphone Amplifier-Preamp
Retail $399
http://www.covalent-audio.com
