Bel Canto e1X energy amplifier
I own and enjoy speakers from seemingly opposite ends of the audiophile spectrum: I’m a huge fan of minimally efficient, but otherwise overcrowded flat panel displays like my Magnepan LRS speakers. But I am just as enthusiastic about another, equally unusual alternative: highly sensitive full-range loudspeakers like my Zu Omens, especially when they are powered by tube electronics. It’s an ongoing yin and yang that keeps my home system in constant flux: switching between speakers that use such different technologies while maintaining a relatively optimal positioning for each is a little daunting. But there is a bigger challenge: finding a single amplifier design that is compatible with both. While tubes would be the obvious choice for the Zu speakers, all-tube amps with sufficient power for my Maggies are definitely outside of my tax comfort zone.
This is where Bel Canto Design from Minneapolis comes in. I’ve heard great things about their Class D solid state amplifiers for a while, but they always existed on the periphery to me: I found Bel Canto amplifiers a little too esoteric for my relatively useful system. But now it’s time to rethink that perspective: with their new e1X line of products – a stereo power amplifier, preamplifier / DAC and integrated amplifier – Bel Canto proposes to make a generous portion of their cutting-edge technology available at significant cost savings . Hence this review of their new e1X stereo amplifier ($ 6,000), which is 40% cheaper than its predecessor in the Bel Canto Black EX range.
The e1X stereo amplifier is indeed a class D design. The rated output power is 250 Wpc at 8 ohms and 500 Wpc at 4 ohms, and the e1X is reportedly stable at 2 ohms. The amplifier also has internal switches that allow you to choose between 27 dB and 33 dB overall gain if required to accommodate different speaker sensitivities. The damping factor of the e1X is greater than 500, the dynamic range 126 dB. I asked John Stronczer, Bel Canto’s Founder, CEO and Chief Design Officer, to explain the Class D technology used in the e1X, and he responded by saying, “The output stage is a low-gain Ncore Class-D stage Extremely low noise and distortion at a current of up to 30 A. The overall architecture of this amplifier (and the other Ncore-based products in our range) is a two-tier architecture with no global feedback.
“The first stage provides most of the gain, either 14 dB or 20 dB, depending on an internal switch setting, and works in class A mode in the e1X amplifier. The second stage is the Ncore modulator, which handles all of the current to the speaker load and provides a gain of 4.5x or 13dB. The first stage amplifier is our proprietary discrete single stage high current Class A amplifier and uses selected resistors and capacitors for the best performance. The signal path from the input stage thanks to the Ncore modulator stage is completely discrete Both in the input and in the Ncore modulator stage there is a loop gain of more than 50 dB in the entire audio band. The result is a constant signature with little distortion throughout the audio band and no coloring that can occur when using feedback without sufficient bandwidth or loop gain in the amplifier stages. ”
Stronczer also noted that the 100kHz switched mode power supply used in the e1X is one of the main reasons for the amplifier’s relatively low mass (see below). The power transformer weighs only about a pound compared to the typical 20 pounds (or more) of conventional 50/60 Hz transformers used in some AB and A class amplifiers. He continued, “The operating frequency of 100 kHz … results in less loss of the magnetic core (a smaller core) and much less copper loss in the transformer. This also results in better supply regulation under load and better response to dynamic load changes. The supply does not suffer from the typical harmonic noise radiation of 50/60 Hz, which can color the midrange range of many audio amplifiers. The resulting clarity in the midrange is evidence of this approach. “Stronczer also mentioned that class D power amplifiers do not fall short suffer from the typical thermal wandering effects that can color the sound of more traditional Class AB designs.
I also asked Stronczer how they managed to bring the price down to $ 6,000 from the $ 10,000 price of its counterpart in the more expensive Black EX line. He told me that while the internal circuitry of the e1X shares much of the goodness of the Black EX amplifier, certain design constraints are required to bring the price down. Basically, the more expensive Black EX amplifier is a more powerful design with an output of 700 Wpc (4 ohms) compared to 500 Wpc of the e1X with the same load. And the Black EX amplifier is a true dual mono design with independent 1200W power supplies and signal paths for each channel. The EX series uses a higher quality silver / gold wiring. The chassis and case design uses machined aluminum panels and is much more robust. However, John assured me that despite significant differences between the two amps, the overall shape of Bel Canto’s other amp offerings is definitely present in the e1X.
Setup and installation
When the e1X arrived, I was immediately impressed by how light the shipping box was: the combined weight of the amplifier and box is only 18 pounds! The e1X is not only light and relatively compact (17.75 “wide × 15.75” deep × 3.25 “high), but also has a clear replacement back panel with the expected connections: single-ended (cinch) and symmetrical ( XLR) inputs. Stereo pairs of WBT Nextgen speaker connections and an IEC jack for the power cord. Michael McCormick, President of Bel Canto, mentioned that the company doesn’t have specific recommendations regarding power conditioning, without which I would be best without closing the Amplifier directly on the wall. My listening room has dedicated AC sockets for audio equipment (Romex 10 gauge sockets, Hubbell sockets). I used a special Rite audio cable to power the e1X has a master switch on the back and a standby switch on the front.
McCormick suggested that I make any necessary device connections first, then let the amp warm up and burn in for at least 72 hours before listening critically. After unpacking, I took the e1X down and swapped it for my Emotiva XPA-1L monoblocks. I noticed what could be perceived as a problem: The housing of the Bel Canto is so incredibly light and unwieldy. B. my MG Audio Planus II speaker cables actually pulled the e1X back and forth over the amplifier stand. (Also note that the speaker connections for both channels are on the same end of the back of the e1X, apparently to keep signal paths short in this non-dual mono design. Again, this made connection a little more difficult than the ideal with bulky cables .) Even with my AudioQuest Yukon XLR connections, the amplifier slid everywhere. I wondered if something even more pointed (or grippy) than the e1X’s tapered footers could make it less prone to movement.
This e1X was generating negligible heat and could certainly stay on.
Listening with the Magnepan LRS
There’s a cult in the audio world for little maggies like the LRS ($ 650 / pair), and I consider myself a believer. Some of us feel that the only thing that sets the LRS apart from Magnepan’s more expensive offerings is a careful amplifier adjustment – and maybe a few well-chosen enhancements. For the latter, I’ve upgraded my pair with a number of custom third-party stands from Magnarisers.com: they have vastly improved the level of performance of the LRS.