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When questioned about the decision to only send hi-rez PCM and DSD via HDMI I2S, Clauzel responded, "Transporting DSD needs either USB, HDMI or more complex solutions like dual AES2. We thought HDMI would be very efficient, robust, and simple. We know that audiophiles aren't very fond of HDMI, but our object was to make a transport and DAC that would fit together without adding a proprietary link between them because we want people to be able to use our transport with another converter. If our customers require that we adapt [because their DACs don't have HDMI ports], we will. If we have to…
Sidebar 1: Specifications
c|AQWO: D/A processor with switchable tube output and outboard power supply. Inputs: 2 S/PDIF (RCA), 2 AES/EBU (XLR), 2 optical (TosLink), I2S (HDMI), USB (44.1 to 384kHz, DSD up to 22.5MHz). Analog outputs: XLR balanced, RCA single-ended. Sample rates: 44.1 to 384kHz, DSD up to 22.5MHz on I2S (HDMI) and USB, 44.1 to 192kHz on S/PDIF (RCA), AES/EBU (XLR), optical (TosLink). Output voltage: 1.4/2.5/3.0V RMS. Output impedance: 100 ohms. Power consumption: 90VA.
Dimensions: 16.93" (430mm) W × 4.72" (120mm) H × 16.54" (420mm) D. Weight: 26.5lb (12kg). Elektra…
Sidebar 2: Associated Equipment
Digital sources: dCS Rossini SACD/CD transport & Rossini DAC & Rossini Clock & Network Bridge; EMM Labs DV2 D/A processor; Apple 2017 MacBook Pro computer with 2.8 GHz Intel i7, SSD, 16GB RAM; Roon Nucleus+; Linksys routers (2), Small Green Computer Systemoptique optical isolation bundle, TP-Link gigabit Ethernet media converters plus multimode duplex fiber optic cable (2); Small Green Computer linear power supply (2) & Small Green Computer/HDPlex four-component 200W linear power supply (2); external hard drives, SSD USB sticks, iPad Pro.…
Sidebar 3: Measurements
I measured the Métronome t|AQWO and c|AQWO using my Audio Precision SYS2722 system (see the January 2008 "As We See It"), making sure that the transport and the processor were each powered from the appropriate Elektra power supply. Although the c|AQWO offers choices of six different reconstruction filters, three different output levels, tube or solid-state circuitry, and both balanced and unbalanced outputs, except when I say otherwise, the measurements were performed from the balanced solid-state outputs set to the highest level, with the Sharp Roll-off filter.…
January's Industry Update included a report on a scientific article presented at last year's AES meeting, in which the authors used test tones and a modest audio system (albeit in an anechoic chamber) to prove that listeners can discriminate between high-rez and CD-rez audio. This is important because scientific evidence of an audible difference between high-rez and CD-rez music is considered weak by some, even as anecdotal evidence grows stronger by the day.
The response to my Update—in the article's online comment thread and elsewhere on the web—was vigorous. Some accepted the result;…
The idea of using digital signal processing (DSP) to convert digital audio data sampled at 44.1kHz or 48kHz to a higher sample rate is not new. I first heard the beneficial effects of upsampling at Stereophile's 1998 hi-fi show in Los Angeles, where a pro-audio dCS 972 digital-to-digital processor was being used to convert 16-bit/44.1kHz CD data to a 24/192 datastream (footnote 1). So persuaded was I of the sonic improvement offered by upsampling that I bought a dCS 972 to upsample CDs to 24/88.2 to feed my then-reference Mark Levinson No.30.6 Reference DAC. As D/A processors improved, my…
In my DAVE review, I concluded that that DAC's "superb re-creation of soundstage depth, its sense of musical drive, and the clarity with which it presented recorded detail were addictive." Listening to this new sample of the DAVE, that is what I heard. But with the DAVE working with CD data upsampled to the maximum rate of 705.6kHz or 768kHz, there was now even more image depth, an increased sense of drive, and even more clarity. These improvements were not just audible with the magnificent Magico M2 full-range speakers; I also heard them with the KEF LS50 minimonitors.
Back in 2017, I…
Sidebar 1: Specifications
Description: Upsampling digital processor with adjustable output sample rate. Digital inputs: 2 coaxial (BNC), 2 optical (TosLink), 1 USB (Type B). Digital outputs: dual-BNC, BNC, TosLink optical. PCM formats supported: 44.1–768kHz, 16/24/32-bit. Included accessories: 15V/4A switching power supply, IR remote control, dual-BNC cables.
Dimensions: 9.25" (235mm) W × 1.6" (40.5mm) H × 9.4" (238mm) D. Weight: 5.6lb (2.55kg).
Finishes: Silver, Black.
Serial number of unit reviewed: 42051, "Made In England."
Price: $4795. Approximate number of dealers:…
Sidebar 2: Associated Equipment
Digital sources: Roon Nucleus+ file server; Ayre Acoustics C-5xeMP universal player; Chord DAVE, PS Audio PerfectWave DirectStream, Mark Levinson No.30.6 D/A processors.
Preamplifier: NHT PVC balanced volume control (with Mark Levinson).
Power amplifiers: Lamm Industries M1.2 Reference monoblocks.
Integrated amplifier: NAD M10.
Loudspeakers: Magico M2, KEF LS50, Vimberg Mino.
Cables: Digital: AudioQuest Vodka (Ethernet), Belkin Gold (USB), Chord (dual-BNC connection to DAVE), Esperanto Blue (S/PDIF to PS Audio), AudioQuest OptiLink (…
Sidebar 3: Measurements
It was difficult to decide which tests would be best at uncovering what the Chord Hugo M Scaler was doing. If I examined, with my Audio Precision SYS2722 system (see the January 2008 "As We See It"), the analog output of Chord's DAVE or another D/A processor when fed upsampled data from the M Scaler, the result would be obscured by the anti-aliasing filter of the AP's A/D converter. I could examine the digital output of the M Scaler, but the analyzer's S/PDIF input is restricted to sample rates of 192kHz and below. Despite these cautions, I feel the following…