Esoteric N-01 network audio player

Ever since the Tokyo Electro Acoustic Company (TEAC) founded its Esoteric division, in 1987, Esoteric's slogan has been "state of the art." Given Esoteric's impressive displays at audio shows, which reflect a consistency of ownership, staff, and philosophy of engineering, design, and manufacturing, I have longed to evaluate one of their hand-assembled models in my reference system. Any brand named Esoteric, and whose top line of products is named Grandioso, had better make superior products.

I've been especially curious about the color and tint of Esoteric's house sound, which to this audiophile's ears has remained relatively unchanged over the years. When the opportunity arose to review Esoteric's flagship network player, the N-01 ($20,000), released in 2017, I leaped.

The N-01 is equipped to decode and play MQA and ultra-high-resolution PCM and DSD files, and offers: 2x, 4x, 8x, and 16x upsampling to a maximum of 768kHz; cross-format conversion of PCM and fixed 22.5792MHz DSD signals, using a proprietary algorithm; and what Esoteric refers to as DSD filtering.

The N-01 is designed to work with a NAS drive, an external HD, USB sticks (FAT32/NTFS format only), an external computer, or a network stream via Ethernet. One USB drive can be hooked up long-term to the Type-A port on the N-01's rear panel, and a friend's device into the convenient Type-A port on the front. I wish every network player had a USB-A port on the front.

The N-01 was still in the process of Roon certification during my time with it (this may have changed by the time you read this). Because my review sample could not yet be configured as a Roon endpoint, it wouldn't recognize my Roon-equipped Intel NUC computer.

The N-01 is mostly controlled by Esoteric's Sound Stream app for iOS, which as of July 2018 included portals for Tidal, Qobuz, Spotify, and TuneIn Internet radio. Playlists and an image cache are two of its many functions.

The N-01 does not have an internal hard drive for content storage. When questioned about this via e-mail, Scott Sefton, Esoteric's longtime marketing specialist for its US distributor, Integra USA, replied: "A) One size would never be the right size—libraries vary wildly—and too much space for one person wouldn't be enough for the next; B) Even though HD performance has improved over the years, it would still be the least reliable part in the component; and C) Hard drives are so inexpensive for consumers, if one were built in, the cost would be higher."

From Sefton and Hiroyuki Machida, Esoteric's general manager of business planning, I learned that the N-01 includes eight DAC circuits and eight power-supply regulators for each channel, and separate dual-mono toroidal power transformers. The N-01 and Esoteric's Grandioso K1 SACD/CD player use the same DAC module, based on the 32-bit AK4497 chipset from AKM. Esoteric claims that its 35-bit internal processing has 2048 times more resolution than 24-bit processing. Central to the design is the Grandioso Custom voltage-controlled crystal oscillator (VCXO) clock, which promises a mean accuracy of ±0.5ppm and low levels of phase noise; still, an external word-clock generator can be connected via BNC to increase resolution and sound quality.


Inside the N-01 are two independent toroidal power supplies, for the network module and digital circuit board. Other key design features include Esoteric's proprietary ES-LINK Analog transmission method, and an HCLD (high-current line driver) buffer amplifier equipped with 125,000µF supercapacitors. Two buffer circuits are employed per channel. Esoteric claims a slew rate of 2000V/µs for "excellent response speed."


The N-01 showed up on my doorstep in a box so big I assumed it was a two-enclosure model. But hidden inside the fourth of four nested cardboard cartons was a single beast 17.5" wide by 6.4" high by 17.25 deep, slung in a cardboard strap whose handles made it easy to lift out its 56.7 lb—assuming one could keep all 16 box flaps open at once.

The N-01 is housed in a two-layer-thick case made of aluminum and steel. Its double-decker interior construction is claimed to reduce interference between circuits and permit shorter power-supply paths for higher sound quality. The lower chassis' base plate of 5mm-thick steel is supported by Esoteric's proprietary vibration-isolating feet. Since circuit-board design is an important factor in the voicing of its products, Esoteric builds its boards in-house using a proprietary solder, in a space that meets the clean-room standards of hospital operating rooms in Japan.

Features and Idiosyncrasies
Because anyone who considers buying a network player will have Internet access, I'll forgo an exhaustive summary of what's made abundantly clear in the online user manuals for the N-01 and Esoteric's Sound Stream app. The N-01's front-panel controls (there is no remote-control handset) let you choose among five inputs, including network, XLR, RCA, USB, and optical. The large LED screen, which can be kept on for a fixed amount of time, dimmed, or turned off completely also displays the file's resolution and format (PCM or DSD). While these are easily readable from across the room, other information, including its MQA indicator and the clock setting, frustratingly appear only in tiny print.


The Esoteric draws 33W, but as my Dan D'Agostino Master Audio Systems Progression monoblocks output 1000W into 4 ohms, I never bothered to use the N-01's Automatic Power Saving mode.

An external computer can't control the N-01 per se, or vice versa —nor can the N-01 send files to the computer. The N-01's output options are unusual. Instead of XLRs with fixed pin settings, you can select XLR2 or XLR3 (pin 2 or 3 hot, respectively). There's also an RCA output and a word-clock input on a BNC jack.

My setup and playback protocols were influenced by another e-mail from Sefton: "While you will have upsampling and filter options that you can experiment with—I suggest you leave upsampling at Original and the filter turned off. These settings will give you the most resolution / shortest signal path, and is how they are set for shows and demos. You can try these out—you might find them 'more romantic' or smoother—but I think after listening to them a while, then turning them off, you will see you will have more detail and resolution with them off. (Humble opinion/experience.)" By phone, Sefton added that playing files in their original formats gives the "most honest and true representation of the music."

I checked with John Atkinson if I should take Sefton at his word. He explained that our readers will need to know about the differences between the various upsampling modes.

Sefton also noted that because the N-01's volume control is digital, the lower the volume level, the more the resolution suffers. He urged me to turn the volume up full and use a preamplifier. I did compare listening to the N-01 direct, with its volume set between 30 and 36 out of a range of 0–100 and outputting the analog signal with the N-01's volume turned up full to an external preamp connected via RCA. Sure enough, in direct mode, lower volume levels produced a flatter, less involving sound. However, I also discovered that, depending upon choice of preamp, not having one in the chain may actually deliver weightier images with greater undertones, overtones and complexity. For some listeners, those qualities may be more important than ultimate resolution.

For listening via a mediating preamp, I tried two: Audio Research's tubed REF 6, and Lamm Industries' balanced hybrid L2.1 Reference two-box model. Both were connected to the D'Agostino Progression monoblocks with runs of Nordost Odin 2 RCA interconnects. While I absolutely love the Lamm's sound—its marginally diffuse, warm, chocolatey midrange is to die for—the ARC's is more straight-ahead, detailed, and transparent, and was easier to find space for on my crowded rack. I stuck with the REF 6.

The Sound Stream app's layout looks a lot like Aurender's, without the distinctive yellow-and-brown color scheme. Sound Stream offers more playlist and display options for USB-stick playback than do dCS's Rossini and Network Bridge apps, and it includes a Qobuz portal, which the dCS app did not at time of writing.

As explained in the manual, it's essential to quit Sound Stream before unplugging USB links or sticks, turning off the N-01, or changing the input. If you don't, the N-01 freezes up, and because there's no master power switch on the N-01's rear panel, the only way to reboot is to pull out the plug and stick it back in. Given that the N-01 froze more times than you might ever wish, I rapidly became a certifiable expert in pulling its power cord out just far enough to turn everything off, then reinserting it, without disrupting a shitload of connector cables.

Esoteric Company
US distributor: Integra USA, Division of Onkyo USA
18 Park Way, Upper Saddle River
NJ 07458
(201) 818-9200

Ortofan's picture

... match the levels as closely as possible in a vain attempt to ensure a level playing field was simply insufficient.
The levels must be matched electrically (at the speaker input terminals) to a precision of within +/-0.2dB - which is equivalent to about +/-50mV relative to a 2V signal.
So, sadly, the outcome of your A/B comparison is of no value.

CG's picture

I'm not sure it's of no value. After all, unless one's head is in the proverbial vise at the listening position, there will be variations of at least 0.2 dB. And, the variations will not be uniform across the audio band. This is but one detail of A/B testing that gets lost in the dogma.

But... Using a wide-enough bandwidth true RMS meter to measure the applied voltage to the speakers is a pretty good practice. If a reviewer wants to make A/B comparisons, I don't think it's unreasonable for them to buy and use some variant of the Fluke 87 multimeter. Its bandwidth is around 20 KHz and it has been available for around three decades. You can buy refurbed meters for a very reasonable price online. Of course, there's other usable meters but the Fluke is pretty widely used and available.

ok's picture

Esoteric’s default digital specs and even crucial measurements seem suspiciously close to Kalista’s recently much maligned ones, while their sonic character appears more like a Yang-Yin opposite thing. Don't really know who to trust these days anymore..

Bogolu Haranath's picture

Police quote: In God we trust. All others are suspects :-) ............

Jason Victor Serinus's picture

we are all manifestations of God. We also have ears. Some of us trust them.

dumbo's picture

Price: $20,000

respectable measured performance

possible 120Hz hum on the DAC chip's voltage reference pin

It sure looks pretty though...Sigh