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I measured the performance of the Reference Two in both full single-ended and full balanced modes. Maximum voltage gains were 15.2dB balanced in to balanced out, and 13.8dB single-ended in to single-ended out. With a single-ended input, the maximum gain available from the balanced outputs was just under 20dB. The preamp was non-inverting from both sets of outputs. The unity-gain settings of the volume control were 2:00 balanced, 2:30 unbalanced.

The preamp's input impedance varied from 52.5k ohms (unbalanced at 20kHz) through 66.5k ohms (unbalanced, bass…

Fig.6 Audio Research Reference Two, balanced HF intermodulation spectrum, DC-22kHz, 19+20kHz at 2V into 100k ohms (linear frequency scale).

Finally, the Reference Two can output very high levels of low-distortion signal into high impedances. Fig.7 shows the THD+noise percentage plotted against balanced output voltage into 100k ohms (bottom trace) and 600 ohms (top trace). The preamplifier doesn't clip (…

I inserted the eVo in my main system in place of the resident McCormack DNA-1 (Rev.A mod) and listened. Ho-hum. The eVo sounded kinda flat in perspective, and thin—not bad, but it seemed in great need of run-in before facing judgment (Bel Canto suggests at least 40 hours).…

That's not what I heard from the eVo 200.2. When I turned up the EVo's wick, everything got louder, but not much closer. The eVo forced me to find the one volume level that suited the sound captured on the…

Description: Solid-state, two-channel power amplifier with "class-T" output stage and two pairs of multiway binding posts. Inputs: 1 pair line-level RCA, 1 pair line-level XLR. Continuous power: 120Wpc into 8 ohms (20.8dBW), 200Wpc into 4 ohms (20.dBW), 1% THD+N. Up to 800W short-term continuous, mono. Input sensitivity for full output: 2V RMS. Input impedance: 20k ohms. Distortion at 1W, 1kHz: 0.01% low-order harmonic, 20kHz measurement bandwidth. Bandwidth: -3dB at 1Hz, 80kHz. S/N Ratio: 96dB A-weighted, ref. 1W out. Stereo mode voltage gain: 23dB. Damping…

Analog source: Heybrook TT2 turntable, SME III tonearm, Ortofon SME30H cartridge.
Digital source: Meridian 508-24 CD player, Meridian Reference 800 DVD/CD player, Mark Levinson No.360 D/A processor.
Preamplification: Sonic Frontiers Line-3, Blue Circle BC21 preamplifiers; Margules/Magenta FZ47dB phono stage.
Power amplifiers: Blue Circle BC22, Bryston 9B-ST THX, McCormack DNA-1 (with Rev.A mod), Sonic Frontiers Power-3.
Loudspeakers: Revel Ultima Studio.
Cables: S/PDIF Digital: Apogee Wyde-Eye, Illuminations D-60. Interconnects, DAC-Preamp:…

Despite its high efficiency, the chassis of the Bel Canto eVo 200.2 was warm after the one-hour preconditioning period at one-third power, though not nearly so warm as would be the chassis of a traditional amplifier with a class-AB output stage. The voltage sensitivity into 8 ohms was low at 24.2dB with both balanced and unbalanced inputs. The single-ended input impedance was a high 109k ohms, this approximately doubling for the balanced input. The amplifier was polarity-correct via both inputs (the XLRs are wired with pin 2 "hot").

The source impedance…

Fig.5 Bel Canto eVo 200.2, channel separation (10dB/vertical div., R-L dashed).

With the output-stage switching noise eliminated by the filter, the true level of measured distortion (fig.6) was low,…

Editor: Stereophile has again produced an accurate and informative review. We are proud of and excited by what eVo technology represents and brings to home audio. When we started our search for a solid-state technology that could capture much of the musical excitement inherent in a good single-ended triode amplifier, we did not know that it would be in the realm of the switching amplifier. Our first exposure to Tripath's new DSP switching amplifier technology demonstration board showed much promise, although it was seriously flawed for a high-end application. More…