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Positive Feedback ISSUE 26
july/august 2006


bel canto

e.One M300 amplifiers

as reviewed by Ed Morawski and Lester J. Mertz




DIY with Scan Speak 9700 & 8535 Drivers and Series Crossover or Magnepan MMG with modified crossover and stands.

Musical Fidelity A308 power amplifier and a BAT VK-3ix preamplifier.

Musical Fidelity A308 CD player (used as a transport), a Tri-vista 21 DAC, and a Roku M1000 SoundBride Music Server.

Empirical Audio interconnects and speaker cables, Stealth XLR interconnects, Analysis Plus Oval 9 Speaker cables, and Cardas Cross XLR interconnects

DIY Flexy rack of plexiglass, dedicated circuits with Brick Wall surge suppression, Balanced power transformer feeding the CDP and Acoustic First foam panels. Vibrapods, Herbie's Magic Feet and good old hockey pucks. Stillpoints ERS paper


Bel Canto's new e.One M300 monoblocks ($995 apiece) are their latest amps based on the ICE power module. When I owned the Bel Canto eVoII Gen 2 digital amps, I preferred to use two of them in bridged mono, for the increased channel separation and power. Perhaps Bel Canto was listening, because the e.One M300s are a similar design in a much more convenient (and attractive) package. When the Bel Cantos arrived, I plugged them into my system, which included my Musical Fidelity A308cr CD player, my BAT VK-31 preamp, and VooDoo cables throughout.

One surprise was the inclusion of balanced (XLR) inputs, an unusual touch at this price point. I didn't hear any difference in my system between the balanced and single-ended inputs, but they're there if you need them. While the e.One M300's are priced attractively, I had an immediate problem with the binding posts. They are WBTs, and are of very high quality, but unfortunately that means that they must meet European safety standards. It also means that it is almost impossible to connect any speaker cables to them. They are completely covered in plastic, aside from a tiny slot for the cables. The spades I use barely fit. The slots were also at extreme angles to each other, so I had to stretch my cables almost at the breaking point to insert them. The posts are also too far apart for standard dual banana plugs.

I'll be honest with you: before I hooked up the e.One M300s, I was not excited about listening to them. "Ho hum," I thought, "another class-D digital amp." That's what I get for thinking; upon listening, I was more than pleasantly surprised. I have had experience with quite a few digital amplifiers, including the aforementioned eVo II, the ClariT, the Flying Mole, and my Nuforce Reference 9.02s. I will probably get rocks thrown at me for saying this, but compared to the e.One M300s all of those amplifiers now seem to me to have a subtle but definite brittleness, and something of a hard edge.

Bel Canto recommends a 100-hour break-in period for the e.One M300s, but right out of the box I knew they were going to be special. To put some time on them, I used them to play background music while working on my computer. More than once, I had to stop and listen. After 24 hours, I couldn't resist a serious listening session. My first impression was that they threw an ultra-wide soundstage, and had incredible channel separation—no doubt because of the monoblock design. My general impression was that they possessed a very high degree of musicality.

I took a glance inside one of the amps, and given my experience with digital designs, I guess I shouldn't have been surprised—but I was expecting more. The metal case contributes 90 percent of the weight, and there isn't much inside. I actually had to search for the power supply, which is on the amplifier board. I checked out Bel Canto's website (, where I learned that the e.One M300s "…use an advanced Switching Power Supply (SPS), which is vastly superior to the line-frequency (50/60Hz) power supplies traditionally used in domestic power amplifiers…. The superiority of the SPS lies in the fact that the final DC power supply voltage is precisely regulated, and largely free of the line-frequency-related noise endemic to traditional power supplies…. Because the SPS first converts the AC to a rectified and filtered DC, it is not sensitive to residual DC on the AC line, and it reduces the amplifier's sensitivity to AC line problems like RF noise, AC distortion, and variations in the line voltage…. The power transformer of the e.One M300 is running at very high frequency (>100kHz), where the magnetic materials are vastly more efficient than they are at 50- or 60-Hz power line frequencies…." This means that "…the power transformer requires less magnetic material and much less copper wire, and can be quite small." The transformers in the M300s are smaller than 2 inches square.

Once again, a component that flies in the face of normal engineering practice manages to do a great job when it comes to reproducing music. The v M300s had a very transparent, yet detailed high end that I really liked. It was never harsh or hard. The midrange was smooth and substantial without being warm, and was on a par with that of some very fine amps. The bass was more than adequately controlled, if not quite as good as that of the eVoII or my reference Musical Fidelity A308. On the other hand, the e.One M300s are the most pleasant digital amplifiers I've heard.

After 72 hours of break-in time, the bass solidified and became quite dynamic, and the upper end was even better than before. On Diana Krall's Look of Love, brushed cymbals sounded extremely detailed, yet had none of the white-noise sound heard with lesser amps. As many times as I've heard this record, I couldn't bring myself to take it off, and listened all the way through. At points where other amps had sounded harsh or irritating, the e.One M300s sounded like honey, yet in no way rolled off. They were amazingly detailed and full bodied. I especially liked the sound of Krall's piano. It took me a while to find a CD player that could do justice to the piano, so I am sensitive to any distortion. The e.One M300s were right on the money.

Tift Merrit's Bramble Rose was next. Merritt has a great country-to-rock crossover voice, and every note of it sounded beautiful through the e.One M300s. The abundant guitars on this recording were also perfectly portrayed. What's an audition without Norah Jones? Some people may be tired of her, but her debut album is, and always will be, a great recording in every way. I really enjoyed it through the e.One M300s. Once again, I listened closely to the piano and the guitars. Both were intimate yet dynamic—a really difficult feat for an amplifier. The following evening, I was forced to listen at a very low volume because my spouse was taking a nap. This proved to be very valuable in my evaluation of the e.One M300s. I was stunned at how good the system sounded with the volume knob barely cranked. The detail and the bass were still there! I cannot remember any other amp that has sounded this good at so low a volume level. Later, when I was able to crank the volume to the max, it was only on some bass-heavy tracks on Madonna's American Life that the e.One M300s began to run out of steam. Even then, I could not hear any distortion—the volume simply wouldn't keep going.

As befits my experiences with all Bel Canto products, the e.One M300s were completely quiet and trouble free. The Bel Canto engineers have done a great job here. The amps exhibited no hum, noise, or weird behavior of any kind. They did not even seem to mind being run with a 4-ohm load.

In summary, the e.One M300s are pretty amazing. I'm not sure how Bel Canto accomplished it, but the e.One M300s have all the best characterizes of solid-state amplifiers—dynamics, bass, and power—with the best characteristic of SET amps—smooth detail. I think their closest competitors are the Nuforce Reference 9s. In a head-to-head, I'd give the prize to the M300s for their top end, but to the Nuforce amps for their low end, though not by much. I found the e.One M300s more pleasant, but that's a personal call. Highly recommended. Ed Morawski

Ed is currently involved in the manufacturing of Olympic Loudspeakers.





DIY - 1. LJM Originals, Transmission Line w/ Dynaudio 17W75 and Morel MDT30, 2. LJM Modified, BK16 – folded horn w/ Fostex FF165K and Peerless Soft Dome, 3. LJM Originals, Floor Stander, w/ Vifa P17WJ and Vifa DX25SG, 4. LJM Modified, Dynaudio "Aries" – (currently on loan to Tim Stant), and 5. LJM subwoofer, w/ Audio Concepts AC12.

Blue Circle BC21.1 preamplifier, Linn phono stage, and Sonic Frontier Power 1 (55w) with Svetlana's 6550c Output, and 6N1P Drivers, B&K ST 140 (105w), and Sound "Valve 110 SE" (on loan from Fred Kat) amplifiers.

Arcam CD 33T, Linn LP12, Grace 707, Signet Mk 110 E (mc) into Monolithic PS 1.

Audience Au24 (on loan from Keith Oyama), Ridge Street Audio Design, "Poiema!!", DH Labs Air Matrix, DH Labs Silver Sonic, LJM, RS microphone, Maple Shade Double Helix, Synergistic Research Active Looking Glass, van den Hul The Second, van den Hul D300 Mk III Hybrid interconnects. van den Hul D352 Hybrid speaker cables. Blue Circle, BC02, Kimber Kord, Synergistic Research, Active, AC Master Coupler, and LJM Originals, Marinco Plugs w/Belden 14-AWG AC cords.

Acme Audio Labs, cryogenic treated outlets and Hubbell, outlets, Mod Squad Tip Toes and cones, Mana Sound Frame, FIM 305 (roller balls), Vibrapods, Maple Shade Iso-Blocks, Maple Shade Maple Boards, Marchland XM9 electronic crossover, Boos Blocks, Rock Maple Granite Slab, Target Stand TTSA5, LJM Wood Blocks/Equipment Stands, VPI 16.5 (record cleaning machine).


Bel Canto is an American company located in Minneapolis. Until now, I had not heard any of its products, and thought it was only known for very expensive tube amplifiers. When I checked out the company's web page to find out more, I discovered that it claims to have the goal of "getting you closer to the original performance." I also learned that it is "committed to technically superior high fidelity solutions," and "[does] not bend to marketing hype or accepted ‘dogma'" in creating its designs. The brief "About Bel Canto" page mentions marketing hype so many times that it sent up an alert to my rational side. Is this company sure that it is avoiding hype? I wondered about such bold statements, and about whether the Bel Canto amps would deliver that special sound that I crave.

The e.One 300 amplifier is available in either stereo (S300) or mono (M300) configuration. It is rated at 150 watts into 8-ohm loads or 300 watts into 4-ohm loads. The amplifier is based on the "ICE power" analog-controlled switching module used by quite a few other companies. The e.One uses multiple feedback loops to provide extremely low levels of distortion, especially the often-overlooked Transient Intermodulation Distortion (TIM). According to Bel Canto, this allows the amplifier to deliver the clean, sweet sound often attributed to low-powered tube amps.

The heart of the e.One amplifier is Bel Canto's regulated switching power supply (SPS) technology, which consists of an input filter, an AC-DC rectifier, a high frequency (>100kHz) switching regulator stage, a high speed rectifier, and an output LC (inductive/capacitance) filter. Bel Canto claims that this design results in a DC supply voltage that is "precisely regulated and largely free of the line frequency related noise artifacts" found in traditional, heavy 60-Hz power supplies. Of course, these types of high-frequency power supplies go back to David Berning's tube amp designs of more than 25 years ago. More recently, they were used in Linn's compact, high-power amplifiers. It didn't seem all that innovative to me, but this kind of power supply does allow for smaller transformers, and thus for reasonably small amplifiers that are easy to accommodate into any system. 

The e.One M300 amps that I received were beautifully put together, and esthetically, a cut above similar switching amplifiers that I have seen. They are compact, and narrow enough to allow the two mono amps to sit side by side on my rack. The thick, brushed metal front panels have the Bel Canto oval cutout, with a blue LED in the center to indicate operation. The nicely executed corners of the chassis suggest extra attention to detail. The back panels have both balanced and single-ended inputs and the newer, plastic-covered binding posts. The speaker connections work exceptionally well with WBT-type spades or bananas, but are not as easy to use with pins or bare wire unless you make sure everything is perfectly aligned. The power switches are also on the back panels, and once fired up, the amps should left on all of the time for best sound. Standard IEC power receptacles are also provided. The supplied power cords were more than adequate, and I noted no improvement with several of the expensive cords that I had on hand. High-frequency power supply amplifiers don't seem to benefit from exotic power cords or power line filters.

The system I used to evaluate the e.One M300s consisted of the equipment that I normally use: an Arcam 33T CD player, a Linn LP12 turntable, and a Blue Circle 21.1 preamp. The only difference was the longer (2-meter) DH Labs interconnects between the line stage and the amps. I wanted to keep things as close to normal as possible, and not charge off into any new directions.

Initially, the sound was warm and round, pleasant enough to let me sit and listen at length without turning me off or sending me over to the TV. However, the soundstage was very shallow, and the sound seemed to be stuck within the speakers, even on recordings that I knew had great depth. This puzzled me, but after about a week of continuous operation, the sound began to improve. The soundstage moved back, and while the sound began to separate itself from the speakers, they still did not disappear. Was more break-in time needed?

After a few weeks of listening, one of my friends brought over another switching amplifier, a NuForce 8.5, and we compared the two amps. The NuForce had a lot more upper midrange energy and detail, but the Bel Canto really nailed the bass in a way that the other amplifier could not match. We both agreed that the Bel Cantos had a better overall balance and a more realistic musical presentation. With both LPs and CDs, the sound was very agreeable. The Bel Cantos sounded almost tube-like, except for the far more realistic bottom end control. Very nice.

Around this time, I played the same cello recording (Jaap ter Linden playing J. S. Bach's Cello Suites) that I used in my first listen. Wow, what an improvement! The instrument was now well into the soundfield, and the speakers had disappeared. This was more like it, and the sound was very close to that of my usual all-tube system. It was well worth the wait. The Bel Cantos never quite achieved the open midrange of a tube unit, but it was very close, and I mean very close—a lot closer to the tube camp than any other transistor amp I have heard recently. I played a wide range of music, from jazz to rock to orchestral, and everything sounded superb. Nothing jarring or discordant ever emerged from the Bel Cantos, just listenable music. Instruments had beautiful timbre, and voices were smooth and inviting. These qualities made for long listening sessions.

System synergy is a factor that simply cannot be overlooked. After two months of pleasurable listening to the e.One M300s, I switched to my 4-ohm Dynaudio stand-mounted speakers and was immediately impressed. The amps sounded more alive with the lower-impedance speakers. The midrange had more articulation and energy. The sound was involving, with great snap and bass impact. I was even more satisfied with the Bel Cantos, perhaps because of the extra power, but I think that the amplifier/speaker match made all the difference.

The M300s have plenty of power for real-world speakers at real-world volume levels. They never seemed to run out of steam, and sounded like they had a lot more power than their rated output. The e.One M300s may be perfect for those of you that don't like to fuss, and for those who are unwilling to deal with tube electronics to get that last bit of magic. There are no output tube changes to contend with, and no searching for that perfect set of tubes. The admission price is a little higher than average for a switching amplifier, but as with everything else, you get what you pay for. The Bel Canto e.One M300s delivered sound that satisfied. They kept me putting on more and more recordings, without any concern about finding that perfect musical match. Bel Canto has come up with a winner here, and I say that with no hype whatsoever. Les Mertz


  • Power output: 300W into 4 ohms, 150W into 8 ohms

  • Minimum load: 4 ohms

  • Frequency response: +/- 0.5dB 20Hz-20kHz, all loads

  • THD+N: 0.01%, 1W, 1kHz, 4 ohms

  • IMD (CCIF): .0.002%, 1W, 14:15kHz, 4 ohms

  • Output noise: 90uVRMS A-weighted 10Hz-20kHz

  • Voltage gain: 27dB (single ended or balanced input)

  • Damping factor: >1000

  • Output Impedance at 100Hz: <8 milliohms

  • Dynamic range: 111dB

  • Input voltage for maximum output: 1.5Vrms

  • Input connections: Single-ended (RCA) or balanced (XLR)

  • RCA input impedance: 10Kohms

  • Balanced input impedance: 20Kohms

  • Output connections: WBT 5-way safety binding posts

  • Size: 8.5" x 3" x 12" (WxHxD)

  • Weight: 9 lbs.

e.One M300 amplifiers
Retail: $1990 a pair

Bel Canto Design
web address: