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The word on Bel Canto's upsampling DAC was already out when I visited their room at the 2000 Consumer Electronics Show looking to get one of the first samples. But despite my protestations, all Bel Canto's Mike McCormick wanted to talk about was their company's new digital amp, the eVo 200.2. Sure, there's a future out there in which all sources will be digital and D/A conversion will occur in the speaker (or later?). But today, I see no practical advantage in a digital amplifier with only an analog input. It may be more efficient and it may be new technology, but the amplifier has got to…
Switch the amp on from the rear, wait a few seconds for the relay to click gently, and there's music. The simple and clear manual was hardly needed except to confirm that the amp is intended to remain powered up. With any of the inputs and any of the speakers I tried, the case of the eVo remained cool to the touch.
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).…
In the home, we turn up the volume to make the audible image of the performance seem larger and, as a direct consequence, the performers nearer. This maneuver should not make the performers sound as if they're playing louder, because the true loudness of the performing instrument is encoded into the recorded harmonic content and dynamic emphasis. At least, this has been my experience.
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…
Sidebar 1: Specifications
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…
Sidebar 2: Associated Equipment
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:…
Sidebar 3: Measurements
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…
The active low-pass filter did come in useful for examining the Bel Canto's channel-separation and THD performance, however. Fig.5 shows the separation, adjusted for the filter's insertion loss. It is quite different in the two directions, the R-L trace showing the usual rise at high frequencies due to capacitive coupling, the L-R showing a pronounced minimum at 2.5kHz.
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,…
Manufacturer's Comment
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…
Kalman Rubinson wrote a Followup in November 2001 (Vol.24 No.11):
How do you know when your system is really loud? If you don't have a sound-level meter, you can wait for your neighbors to complain or for your ears to bleed. But long before that point, a system will begin to give telltale signs—like dynamic compression and increased distortion, which are often misinterpreted as meaning "loud" rather than "distorted."
Well, I don't generally get to that point with my regular equipment and musical preferences, and when I auditioned the $2395 Bel Canto eVo 200.2 power amplifier for…
Kal Rubinson wrote again about Bel Canto in December 2002 (Vol.25 No.12):
I had reviewed the original Bel Canto eVo 200.2 quite favorably in the March 2001 Stereophile (Vol.24 No.3), but was somewhat surprised by John Atkinson's decision to put it in Class A of "Recommended Components." It was a breakthrough for high-end amps in terms of technology and efficiency, but it was less than the state of the art in transparency and lack of grain. Moreover, JA and I had problems getting it to put out full rated output because of its built-in protective current limiters. Snipping out the limiting…