Digital technology
The Classé Omega is said a no-compromise design. All data and control signals from the transport…
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'Round back of the player are two sets of outputs: one of XLRs (pin 2 hot) for balanced running, another pair for single-ended. Over at the other side of the back panel, on the bottom, to the left of the socket for the power-supply umbilicus, are two digital inputs: S/PDIF on RCA and TosLink. Above these are the digital outputs: AES/EBU, S/PDIF on RCAs, an AT&T glass output (not seen much these days), and two IR trigger input/output connectors on 1/8" miniplugs.
And back to analog
The analog circuitry comprises three sections: the analog filter, the current-to-voltage conversion, and the output driver. All are unusual in the Omega SACD. The analog filter is a second-order passive type. Because of its 12dB/octave rolloff, it doesn't offer the same out-of-band rejection of a more complex, steep-slope filter, Classé's white paper explains. "However, with a corner frequency at 35kHz and 96dB of attenuation at 2MHz, this filter provides more than sufficient noise suppression to prevent both audible artifacts and intermodulation distortion."
The analog circuitry comprises three sections: the analog filter, the current-to-voltage conversion, and the output driver. All are unusual in the Omega SACD. The analog filter is a second-order passive type. Because of its 12dB/octave rolloff, it doesn't offer the same out-of-band rejection of a more complex, steep-slope filter, Classé's white paper explains. "However, with a corner frequency at 35kHz and 96dB of attenuation at 2MHz, this filter provides more than sufficient noise suppression to prevent both audible artifacts and intermodulation distortion."
The…
Next, I turned to the hybrid SACD/CD Lyrinx disc of pianist Caroline Sageman playing Chopin. Morbidly, perhaps, I played Scherzo 3 in C-sharp minor, Op.39. You know...dumm dumm dee-dumm, as the imaginary casket moves toward the loamy earth. I always liked the slow stuff. And I was surprised to read in the booklet that, "even as a child, [Sageman] preferred slow movements, the more dramatic pieces....Still today she has a particular affection for these works which allow her to penetrate the music more easily, to be able to isolate herself." The SACD layer communicated this feeling exquisitely…
Sidebar 1: Specifications
Description: SACD/CD/CD-R player with balanced (XLR) and single-ended (RCA) line-level outputs, and external power supply. Digital inputs: S/PDIF on RCA and TosLink; both accept PCM from 32 to 96kHz. Digital outputs: S/PDIF on RCA, AES/EBU on XLR, optical (on ST connector); internal sample-rate converter to 96kHz; digital outputs do not function during SACD play. Power consumption: 50W. No other specifications provided.
Dimensions: Player: 19" W by 5 3/8" H by 15" D. Weight: 37 lbs. Power supply: 9½" W by 3¾" H by 15" D. Weight: 10 lbs.
Serial number of…
Sidebar 2: Associated Equipment
Digital source: Accuphase DP-100 SACD/CD transport and DC-101 upsampling DAC, Linn Sondek CD12 CD player.
Preamplifiers: Conrad-Johnson Premier 17LS, Lamm L2, Mark Levinson No.32 Reference.
Power amplifiers: Krell FPB 350mc and Linn Klimax Mono 500 monoblocks.
Loudspeakers: JMlab Utopia.
Cables: Interconnect: Synergistic Research Designer's Reference with Discrete Shielding, TARA The One ISM Onboard, Cardas Golden Reference. Speaker: AudioQuest Everest, Cardas Golden Cross, XLO The Limited. AC: PS Audio Lab Cable, Synergistic Research Designer'…
Sidebar 3: Measurements
Like the Sony transport on which it appears to be based, the Classé Omega takes quite a while to read a disc and decide whether it can be played. However, it does read CD-Rs, so I was able to perform a full suite of tests on it. (Many of my CD-player test signals have been generated in the digital domain using an Audio Precision System One Dual Domain and burned onto CD-R.)
The Omega's error correction was good, but not in the class of the best DVD transport-based players I have experienced of late. It started to mute when playing track 31 on the Pierre…
The presence of this ultrasonic noise with SACD can also be seen in fig.5, which shows wideband spectral analyses of both SACD and external 24-bit sources with a dithered 1kHz tone that is actually below the Omega's noise floor. (I usually use "digital black" for this test, but the Omega appears to shut off its analog output when it detects this signal.) The LPCM data results in a "white" noise floor that starts to rise above 50kHz, presumably due to the sigma-delta DAC's own noise-shaping. However, the DSD data result in a noise floor that peaks at -42dB around 120kHz, before rolling off at…
By contrast, fig.9 shows a similar spectral analysis for the balanced output into the same high (100k ohms) load. Balanced operation tends to cancel even-order harmonics, hence the disappearance of the fourth harmonic in this graph compared with fig.8, and the halving in level of the second from -76dB (0.015%) to -83dB (0.007%). But the third harmonic has increased by almost 20dB, to -58dB (0.12%)!
Fig.9 Classé Omega, balanced spectrum of 50Hz sinewave, DC-1kHz, at 0dBFS into 100k ohms (linear frequency scale).
Thankfully, things don't get significantly worse into the…
Manufacturer's Comment
Editor: The Classé design team thanks Jonathan Scull for his rigorous review of our new SACD/CD player. He was able to hear (and confirm our own findings) that there is still a little more to discover in the discs in the vast music libraries Stereophile readers now own. More important, he discovered the even richer possibilities appearing in the SACD format.
Regarding the high level of crosstalk that John Atkinson measured on the RCA outputs only: Because he found the crosstalk on the balanced outputs to be as low as our specs, we believe the culprit is a…
A man who had just looked through his very first Stereophile---April's "Recommended Components" issue picked up at a newsstand---recently called to ask my advice on a certain inexpensive CD player made by a large mid-fi company. I told him I hadn't auditioned the player and thus couldn't comment on its worth. The man then proceeded to read me the player's specifications, finally informing me that the player "had the new 1-bit thing"---all in the belief that I could make a recommendation based on what he'd just told me. He apparently had been conditioned to believe that not only was "the 1-bit…