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RH salivated over the Spectral SDR-2000 Professional HDCD D/A processor in Vol.18 No.5, and this was my first chance to hear it in my system. He did not exaggerate. It is clearly a Class A processor; it may even be the best processor in Class A, though I haven't had the opportunity to compare it directly with the Mark Levinson No.30.5, which isn't exactly chopped liver (footnote 1).

At first I found the differences between the SDR-2000 and the Mark Levinson No.36 D/A converter to be subtle—less notable…

Description: Digital Processor with HDCD decoding. Inputs: three coaxial on RCA jacks, two AES/EBU on XLRs, TosLink optical, Spectralink. Controls: digital input select, polarity inversion, mute, display dim, operate/standby. Sampling rates supported: 44.1kHz, 48kHz. D/A conversion: four custom 20-bit DACs in balanced configuration. Digital filter: Pacific Microsonics PMD100 8x-oversampling. Analog filter: passive, linear phase to 22kHz. Frequency response: DC–22kHz ±3dB (limited by encoding). DAC step resolution: 5µV or less. Digital noise output: 100µV p-p or…

I listened to the SDR-2000 Pro at the front of my usual reference system, and with an all-Spectral playback system with MIT loudspeaker cables and interconnects. The people at Spectral believe that their electronics and MIT cables are needed to fully hear the SDR-2000 Pro's musical performance. Although I agreed to replace my usual amplification and cables for part of this review, auditioning the SDR-2000 Pro in my familiar reference system was mandatory.

My system consisted of a Mark Levinson No.31 CD transport feeding the SDR-2000 Pro via…

The SDR-2000 Pro's maximum output level was lower than that of most processors, measuring just 2.06V from the balanced outputs and 1.03V from the single-ended outputs. These low levels are a result of the 6dB attenuation in the SDR-2000 Pro's analog stage to conform to the HDCD requirement. When playing HDCD-encoded discs, the maximum levels will be 6dB higher: 4.12V from the balanced outputs, 2.06V from the single-ended outputs.

The output impedance measured 200 ohms from the unbalanced jacks, 400 ohms from the balanced outputs at any audio frequency. DC…

Early Sunday, CAF issued this statement, signed by show founder and organizer Gary Gill:

Can you tell a product…

Description: Solid-state stereo amplifier. Rated output power, 20Hz–20kHz, with no more than 0.5% THD (FTC): 300Wpc minimum continuous into 8 ohms (24.8dBW); 600Wpc minimum continuous into 4 ohms (24.8dBW); 1200Wpc continuous into 2 ohms (24.8dBW). Frequency response: 20Hz–20kHz ±0.05dB. S/N ratio: &#6280dB (ref. 1W). Input impedance: 100k ohms balanced, 50k ohms single-ended. Voltage gain: 26.8dB. Input sensitivity (for 2.8V output): 130mV. Input sensitivity (for full output): 2.25V. Output impedance: <0.05 ohms, 20Hz–20kHz. Damping factor: !w800, 20Hz–…

The preamplifier was the remote-controlled Mark Levinson No.38S, with either a Mod Squad Phono Drive EPS or an Audio Alchemy VAC-in-the-Box used to amplify LP signals from a Linn Sondek/Cirkus/Trampolin/Lingo/Ekos/Arkiv setup on an ArchiDee table. Digital sources were MLevinson No.30.5 HDCD and Parts Connection Assemblage D/A processors driven by Mark Levinson No.31 and No.31.5 transports via Madrigal and Illuminati AES/EBU cables and Meridian 518 or Genesis Digital Lens jitter-reduction units (No.31) or Sonic Frontiers UltraJitterbug (Assemblage). I also used…

All of the No.333's measurements were taken using the balanced inputs. After a one-hour, 1/3-power preconditioning, the heatsinks were too hot to keep my hands on. The wideband S/N Ratio (ref. 1W into 8 ohms) measured a reasonable 62.5dB, this improving to 79.5dB when A-weighted. The channel separation (not shown) was better than 90dB below 5kHz, decreasing above that frequency to a still-good 70dB at 50kHz, due to capacitive coupling between the channels. The amplifier's voltage gain into 8 ohms measured 26.7dB, it didn't invert polarity, and its input impedance…