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Back in the summer of 2009, USB-connected D/A processors that could operate at sample rates greater than 48kHz were rare. Ayre Acoustics had just released its groundbreaking QB-9, one of the first DACs to use Gordon Rankin's Streamlength code for Texas Instruments' TAS1020 USB 1.1 receiver chip. Streamlength allowed the chip to operate in the sonically beneficial asynchronous mode, where the PC sourcing the audio data is slaved to the DAC. But high-performance, USB-connected DACs like the Ayre were also relatively expensive back then, so in the January 2010 issue of Stereophile I reviewed a…
The midrange receded slightly with upsampling engaged, as Michael Lavorgna described in his review. The voices in the Bachian arrangement of Noël Coward's "I'll See You Again," from The King's Singers Sing Flanders & Swann and Noël Coward (24/192 ALAC file from 1977 LP, EMI EMC 3196), acquired a touch more palpability. However, the recording lost a little bit of "air" around the singers' images, and the inevitable ticks in this needle drop sounded slightly softer. Augustin Dumay's performance of Beethoven's Violin Sonata 3 in E-flat, from his complete set of the sonatas accompanied by…
Sidebar 1: Specifications
Description: Upsampling, stereo D/A processor/headphone amplifier with independent volume controls for line-level and headphone outputs. Digital inputs: 1 S/PDIF (coax), 1 S/PDIF (TosLink), 1 USB 2.0 (type B). Analog outputs: 1 pair balanced (XLR), 1 pair unbalanced (RCA), 1 headphone output on ¼" (6.3mm) stereo phono jack. Compatible sample rates: 44.1–192kHz, all inputs. Frequency response: 10Hz–48kHz, –3dB, with 192kHz data. Channel separation: not specified. Signal/noise: 120dB ref. 0dBFS, A-weighted. THD+noise: >0.000316% (–110dB) at 0dBFS. Maximum…
Sidebar 2: Associated Equipment
Analog Source: Linn Sondek LP12 turntable with Lingo power supply, Linn Ekos tonearm, Linn Arkiv B phono cartridge.
Digital Sources: Marantz Reference NA-11S1 media player; Ayre Acoustics C-5xeMP universal player; Apple 2.7GHz i7 Mac mini laptop running OS10.7, iTunes 10, Pure Music 1.89, Audirvana Plus 1.5.10, JRiver Media Center 19 for Mac; NAD M51, Channel Islands Transient Mk.II, Auralic Vega D/A converters; Ayre Acoustics QA-9 USB A/D converter.
Preamplification: Channel D Seta L phono preamplifier, Pass Labs XP-30 line preamplifier.
Power…
Sidebar 3: Measurements
I used Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It") to examine the ASUS Xonar Essence One Muses Edition's measured behavior. I used my 2012-vintage Apple MacBook Pro running on battery power to examine the processor's performance via its USB port. Apple's USB Prober utility confirmed that the USB port operated in isochronous asynchronous mode and reported the processor's product string as "ASUS Xonar Essence One\000" from "ASUSTek Computer Inc." Peculiarly, the Mac's AudioMIDI…
Responses to the 1985 "Carver Challenge" (from February 1986, Vol.9 No.1):
Publisher's note: We anticipated a far stronger response to Bob Carver's duplication of the sound of our chosen reference amplifier (Vol.8 No.6), but the two comments below were the only official replies we received. On the other hand, many people in the industry spoke to us off the record, some in admiration, some in envy, some with a kind of disgust. I'm sure other amplifiers will come along that seem to defy duplication; perhaps Bob will be up to another challenge in a year or so.—Larry Archibald
From…
AudioQuest DragonFly v1.2, from March 2014 (Vol.37 No.3):
I did all of the headphone comparisons in the March 2014 issue of Stereophile sitting at my desk, staring at my laptop, and using the latest version of AudioQuest's popular DragonFly USB DAC–headphone amplifier. Aside from some small, tidy certification markings on its backside, the DragonFly v1.2 is identical in size, shape, and functionality to the original model—and, at $149, costs $100 less. Like the original, the v1.2 handles file resolutions up to 24-bit/96kHz, making the device virtually plug-and-play for both PC and Mac…
I know this will come as a huge shock to music fans the world over but the Grammy Awards get it wrong more than they get it right. No offense to the 2013 winners, but after repeated listens to the LP of Bakersfield, which was cut from a digital master, and the CD of the same record, (no high resolution download yet) it’s very clear that the best country record of 2013 was easily this delightful throwback that reminds you again, that once upon a time Nashville wasn’t the only game in the country universe. A lot of what is now thought of as “classic country” was written in California by the…
In his article on the future of audio engineering in this issue, John La Grou tells us—succinctly and correctly, I think—that we are rapidly moving from a culture of handheld devices to one of headworn devices. He postulates that by perhaps as early as 2025, rather than being actively sought out, most audio/video media will be delivered, like milk or the newspaper—but delivered not to our front doors, but more or less straight to our brains. Fascinating? Sure. Frightening? Kinda, yeah. I'm just getting used to Instagram (@stephenmejias), and now I have to prepare for InstaEverything—in my…
By comparison, the older model offered a brighter, edgier overall sound. Individual voices and instruments were slightly less well defined and not as precisely located on the soundstage. And, most significant, rhythm, pacing, and overall control suffered: Snare-drum strokes now evaporated too quickly, ride cymbals splashed where they shouldn't, and the drums seemed altogether a bit ahead of the music. It was as if the band were just a little anxious to get off the stage, whereas before they were content to groove and sway. The new DragonFly added the color, texture, body, and soul that the…