search

I measured the Acoustic Research AR-M2 with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). Source materials were WAV and AIFF test-tone files, as well as DSD64 and DSD128 files of test tones prepared for me by Malcolm Hawksford. The AR-M2's battery was fully charged at the start of the testing.

The maximum output level was 1.89V from the line output jack and 3.71V from the headphone jack, both with the volume set to its maximum. The output impedance was 100 ohms from the line-out jack and 10 ohms from the headphone jack, both…

Analog Sources: Garrard 301, Thorens TD 124 turntables; Abis SA-1.2, EMT 997 tonearms; EMT OFD 25 & OFD 15 & TSD 15 pickup heads; Denon DL-103, Miyajima Premium BE Mono II cartridges.
Digital Sources: Halide Designs DAC HD USB D/A converter; Apple iMac G5 computer running Audirvana Plus 1.5.12; Sony SCD-777ES SACD/CD player.
Preamplification: Hommage T2 step-up transformer, Shindo Laboratory Aurieges Equalizer Amplifier phono preamplifier & Masseto preamplifier.
Power Amplifiers: Shindo Laboratory Corton-Charlemagne monoblocks.
…

I performed a full set of measurements on the April Music Aura Note V2 using my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I looked first at the behavior of the digital inputs, using either S/PDIF data sourced from the Audio Precision via an optical link, or USB data from my MacBook Pro running on battery power. To avoid overloading the April's power-amplifier section, I examined the signals at its line-output jacks without any load attached to the speaker terminals. (Plugging headphones into the headphone jack mutes both the speaker and…

Saturday April 2, from 11am–7pm, Whetstone Audio (2401 E. 6th St #1001, Austin, TX 78702) are presenting John DeVore of DeVore Fidelity and Mike Pranka of Well Tempered Lab playing the new Gibbon X loudspeakers and Royale 400 turntable. There'll be food, drinks, and a Rega RP1 turntable for a lucky winner! Please RSVP: (512) 477-8503 or brian@whetstoneaudio.com.

On the Outside
Designed in California and manufactured in South Korea, Aurender's N10 is a smart-looking…

Description: Media Server running Linux. Formats supported: WAV, AIFF, FLAC, ALAC, AAC, M4A, MP3, APE, DSF, DFF. Internal storage: 4TB (two 2TB hard disks) plus 240GB solid-state cache drive. Resolution and sample rates supported: PCM up to 32-bit/384kHz, DSD64, DSD128. Inputs: Ethernet, two USB Type A. Outputs: USB Class 2.0 (Type A jack), AES/EBU (XLR), S/PDIF (coaxial RCA and BNC), TosLink optical.
Dimensions: 16.77" (430mm) W by 3.24" (83mm) H by 13.77" (353mm) D. Weight: approximately 26 lbs (11kg).
Finishes: Silver, black.
Serial number of unit…

Digital Sources: Apple 2.7GHz i7 Mac mini running OS 10.10.3, iTunes 12, Pure Music 2.0, Audirvana Plus 1.5.10; Antipodes DX Reference music server; iPad mini running Aurender Conductor app for N10, iPeng 8 for Antipodes DX; PS Audio PerfectWave DirectStream D/A processor; AudioQuest JitterBug USB noise filter; UpTone Audio USB Regen.
Preamplifier: Ayre KX-R Twenty.
Power Amplifiers: Vandersteen M7-HPA monoblocks.
Loudspeakers: Vandersteen Model 7 Mk.II.
Cables: Digital: AudioQuest Coffee (USB) & Vodka (Ethernet), Kimber Kable Orchid (…

With a media server like the Aurender N10, there's not much that can be assessed on the test bench. However, I did look at the properties of the N10's AES/EBU output, using a 45'-long cable to connect the N10 in the listening room to my Audio Precision SYS2722 in the test lab. Even so, with the N10 playing 24-bit J-Test data sampled at 44.1kHz, the jitter in the AES/EBU datastream was very low, at 293.3 picoseconds (average value over a 700Hz–100kHz bandwidth). The eye pattern (fig.1) was wide open, as it should be.

That's what members of the Smoky Basement Secret Audio Society would exclaim in unison at the end of each ceremony admitting a new devotee. It was called the Smoky Basement Society not because everyone smoked (though they did), but because its members believed that whenever an audio designer finally got a design dialed in just right, he or she had metaphorically "let the smoke out." They exclaimed, "Hail, Neophyte!" because they believed that the most important aspect of being an audio engineer was to have a fully open "beginner's mind." In Zen practice, this is called…