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Reviewer: John Potis
Analog Source: Rega P9 turntable, RB1000 & Hadcock GH Export arms, Rega Super Elys & Garrott Bros Optim FGS Cartridges
Digital Source: Accustic Arts Drive 1, Audio Aero Prima SE DAC
Preamp: Bel Canto Pre2P
Power Amp: Art Audio Carissa, Bel Canto e.One REF1000 and Canary CA 160 Mono Blocks, Musical Fidelity A5 Integrated
Speakers: Tidal Audio Pianos, Hørning Perikles, Anthony Gallo Acoustics Reference 3.1, Ohm Acoustics Walsh 4 with 4.5 mk.2 upgrade, Thiel CS 2.4
Cables and Wires: JPS Labs Superconductor 3
Power Cords: JPS Power AC, Analog AC, Digital AC and Kaptovator power cords, ZCable Heavys, Red & Black Lightnings
Powerline conditioning: Balanced Power Technology 3.5 Signature Plus with ZCable Cyclone Power Cord
Sundry accessories: Sound Mechanics Performance Platform, 2-inch Butcher Block platforms with Quest for Sound Isol-pads, Vibrapod Isolators and Cones, Ultra & Heavy ZSleeves, Viablue QTC spikes under speakers, Auric Illuminator, Gingko Audio Mini-Clouds
Room size: 12' by 16' with 9' ceiling
Review component retail: $4890/pr, $1390 to modify your amps


I've been observing for a while now the way some readers respond to the 'positive review'. Did the reviewer love it or hate it? If it didn't work in his system, then surely it's not worthy of your consideration. If he liked it, then it must be just what the doctor ordered. Wrong. Positive or negative, so far more important than whether or not a reviewer liked a component is the description of what exactly the piece sounded like. Sometimes I can't really blame readers for their mindset though. At the completion of certain reviews, if you were asked to recap how the writer described the sound, you might feel at a loss.


You may well notice that certain writers seem to think the most important thing for you to know is that they really enjoyed the product. Enthusiasm seems more important than the details of what was heard. This is simply wrong-headed. It's also lazy reviewing but I guess it falls under the heading of entertaining writing. Style over substance may make compelling reading but it makes for bad counseling.


Stereophile's preamble to their recommended components list has been spelling out the fact that skimming through the list and randomly picking this and that component will not guarantee a good sounding system. The RC list is an inventory for your consideration, not your purchase. Consideration means that you research and listen for yourself to determine if, when combined with other components under consideration, a particular one will add up for a synergistic match that conforms to your idea of a musical system. This is a concept that seems to elude even the list's most vocal detractors.


How can there be so many Class A rated components? How can there be both inexpensive and ultra-expensive components in the same category? Shouldn't the more expensive components be eliminated if only because they're more expensive than the rest and therefore poor value? I don't think so at all. Just because there are less expensive components of similar ranking doesn't mean they'll work for you in your system. Sometimes they will - count yourself lucky. Sometimes they don't though and in such a case, readers are fortunate for having a more exhaustive list of components worthy of consideration. Just because you favor a drier wine doesn't mean that a sweeter one doesn't tickle my fancy. One isn't better or worse, they are just different. If you choose a highly recommended sweet wine when what you fancy is a dry one, no matter how great of an example of a sweet wine it is, you're not going to be happy. And nowhere is there a greater audio example of how faulty this notion of right and wrong is than with Underwood HiFi's Level 2 modified Bel Canto e.One Reference 1000 monoblock amplifiers.


The e.Ones are a favorite of mine and I own a pair. Upon the completion of their review, they became the first-ever electronic component to receive our Lunar Eclipse award. When I consider their price, their performance and their size, I'm forced to put them in a class of their own. So when Underwood's Walter Liederman approached me about a review of his modified Ref 1000s, I was torn. I liked mine very much. Likely, the modified version was different. But would it really be better? And what if I liked it? What if I loved it? Did that mean I was in error with my Lunar Eclipse award? Was this entire topic something best avoided? No, of course not. If it's not already clear, the point I've been trying to make is that it's unimportant which version of the Reference 1000s amps I liked best. The point is how do they differ and which one is likely the better fit in your system.


Back to the beginning
If you're not already familiar with the Bel Canto e.One Reference 1000 amplifiers, I refer you to my original review. If you're even considering the modified version, it's mandatory reading. It goes into more detail regarding the amplifiers' basic personality than I plan to go into here. Briefly, the Ref 1000s are small, light and highly efficient analog switching amplifiers that pack roughly 25 pounds of muscle in their diminutive frames. Producing 500 watts each into an 8-ohm load, they double their output into 4 ohms and are said to be stable into 2 ohms. They are highly efficient and get only slightly warm to the touch as they drive my 4-ohm Thiel CS 2.4s with finesse and brawn.


Where the Reference 1000s are concerned, I found myself completely enamored with their harmonic saturation, their density of both image and tone. Light and airy? Nope. The Bel Cantos forego a big airy and ethereal presentation in favor of one that's solid and almost visual. The music has way too much meat on its bones to qualify as truly see-through. So rich and full of color are the Ref 1000s that they out-tube some tube amplifiers. Don't think syrupy, amber or romantically colored in the old-fashioned tube sense or you'll be way off base. However, think good clean modern day tubes -- just extremely powerful ones -- and you'll be on the right track. Think lean, threadbare and bright and then consider their inverse. Now think big powerful tube sound without the heat, maintenance and expense and you complete the picture. You'll also understand why I enjoy them so.


Now enter Walter Liederman and Chris Johnson. Liederman heads up Underwood HiFi and Johnson is the founder and former president of Sonic Frontiers and now the Parts ConneXion. For years these two have been modifying components from various manufacturers. 6moons has had the pleasure of enthusing over several of them over the last few years but I believe this is the first time we've been in a position to compare modified against stock.


The buyer has the choice of two levels of modifications. Level 1 addresses certain issues and Level 2 builds further upon them.


Level 1 Modification
a) Johnson installs eight Japanese Riken ½ and 1-watt 'signal path' carbon resistors w/gold-plated leads
b) Six feet of DH LABS 18 AWG 'Revelation series' pure 99.999% silver solid core input signal wire with Teflon tape-wrap dielectric
c) Four premium WBT-0763 single output binding posts to replace the stock terminals
d) Four Black Gate ultra-premium electrolytic capacitors
e) One sheet of Soundcoat chassis damping material cut and applied where applicable
f) One sheet of ERS EMI/RFI suppression paper in critical locations
g) Ten feet of TRT WonderSolder throughout
h) 4 hours labor
The Level-1 modification costs $990.00 per pair plus shipping or you many purchase a new modified pair for $4,490.00/pr plush shipping.


Level 2 Modification
All of above plus:
a) One pair of WBT next Gen 0210-cu copper RCA jacks
b) WBT Next Gen Copper 0710-Cu speaker terminals
c) Replacement of the inexpensive ribbon cable connection between the input and ICE PCBs two entirely new ribbon connectors using 12 feet of DH LABS 23 AWG 'Revelation Series' pure 99.999% silver solid core umbilical signal wire with Teflon tape-wrap dielectric. These cables are custom fabricated and hand soldered into the circuit.
d) Two additional hours of labor for a total of 6 hours.
The price of a Level-2 modification to your pair of amps is $1390.00 (excluding shipping) or $4890.00/pr plus freight for a new modified pair..


Underwood HiFi offers their own two-year warranty (parts and labor) on new amps, the same as offered on Bel Canto amplifiers but you'd send Underwood the amplifiers should you encounter difficulties. Modifications to your amps come with a 1-year warranty on all custom work done.


My review pair arrived with the Level 2 modifications. Right out of the box and with about a half-hour of warm-up, my first thoughts were, "Congratulations. You've succeeded in making a great amplifier sound like everybody else's." Out of the box, the amps are much more reminiscent of the average $1500 integrated amp than what they'll eventually morph into. You'll have to be patient. I knew that Black Gate caps are notorious for protracted break-in so I fired off an inquiry and was told to give 'em 200 hours. Out of the listening room they went to spend better than a month in another room breaking in the Hyperion HPS-968 loudspeakers I've got warming in the wings. I've enjoyed the combo greatly, albeit on a very casual basis. But you may want to spare yourself the initial hours of disappointment and set them up in the garage with a tuner and a pair of monitor speakers for a few weeks.


When it came time for them to go back into the music room, it was immediately apparent that these amps were neither the ones I'd listened to several weeks prior nor were they my personal pair. However, there were some strong similarities. Retained was the solidity and power of the stockers. That magic was still there. Images have an almost reach-out-and-touch realism and presence. There's real heft. Focus is excellent. That's the good news. No matter which version you choose, you get what makes the Bel Canto Reference 1000s stand alone.


That's also just about where the similarities quit. I don't want to convey that these are night and day differences. The two versions of the amps don't sound so different that you'll hear one pair in one shop and the other across town and be blown away by the difference. But side by side there are differences and important ones at that. They make choosing between the two amps a matter of deciding which one best suits your system.


From little acorns mighty oaks do grow.
First, the Underwood Level 2 modified amps are brighter than stock. Slightly more forward, too. Not drastically so but easily observably if you know the stock amps' signature. They sound slightly more open through the midrange as you would expect from such a change. They also seem to retrieve detail slightly better as well. Seem to? Without question the Level 2 modified amps are more forward and they make those details a little more obvious, much as shedding additional natural light on the object to be photographed will. But I'm not prepared to say that the stock amps are capable of less detail. It's just that the mod projects them a little more, makes them just a little more obvious. Moving on, the amps are more illuminated through the upper midrange and treble. High percussion and chimes in particular become much more vivid in an almost disproportionate manner with the actual change in tonal balance. In other words, this added presence is much greater than the perceived change in brightness. That's a good thing. Turn up the treble control on a receiver and you'll observe a similar added presence, but at the expense of what is probably a harder treble and excessive sibilants. Unless there's something wrong with your speakers or unless your system is already teetering at the point of excessive brightness, the marginal change here shouldn't be enough to cause those types of problems.


The title cut from Supertramp's Some Things Never Change [Oxygen/SilverCab 63245-90002-2] provided an excellent opportunity for the modified amplifiers to strut their stuff. The opening drum riff came across with crystalline clarity and a sharply focused leading edge backed up with a fulsome and highly detailed body that pulsed with resonance. The best SET amps I've heard don't give me a clearer window here nor do they provide the same kind of weight way down low. Up higher, the percussion was crisp without becoming irritating, sibilant or edgy with hash.


Eric Johnson's Ah Via Musicom [Capitol CDP 7 90517 2] is a bright disc I've been enjoying a lot lately. As much as I dig the music, the fact is that I've been using it a lot lately as a torture disc to demonstrate how a component under review will deal with bright recordings. As long as a component allows the recording to sound like what it is without over-sweetening it or making it sound harder and brighter, I know the component is doing its job and operates within an acceptable tolerance of neutrality. This disc really highlighted for me the difference between these amps and my twice as expensive 26-watt 300B Canary CA 330 push/pull tube amplifiers. I was relieved to hear that while these modified amplifiers may be slightly brighter, they are not bright per se. In the areas of upper frequency transparency and delicacy, they still fall short of the Canary tube amps. That should surprise no one. But I found the overall frequency balance very similar to what I've been enjoying with the Canary amplifiers.


I also failed to get their same kind of highly illuminated soundstage and airy presence but through the midrange, the modified Bel Cantos did a really super job as usual. They still couldn't match the sharply focused images or the highly delineated outlines of the Canarys, however. And they oh-so-slightly smeared the timing cues as they didn't quite let go of the notes as well either. But I'll be damned if they didn't come embarrassingly close for a solid-state amplifier of such modest price and gargantuan power reserves. Through the midrange, these Bel Cantos, either stock or modified, are fully the match for any KT88 or 6L6 tube amplifier I've ever used. Where they differentiate themselves from some of the better EL34 amplifiers is in the way they don't sweeten the pot. They are more of the truth-and-nothing-but-the-truth breed. Johnson's "Steve's Boogie" has a slight Country beat'n'twang to it and the recording process wasn't overly kind to the crisp percussion but the Bel Cantos weren't completely without mercy. This was listenable and non-irritating while at the same time articulate, incisive and energetic. Here the Level 2 modified amps struck a very fine balance between incisively lively and irritating.


Bass sounds more penetrating through the Level 2s. I don't wish to draw any equivocations between the Bel Cantos and a mass market receiver but, again, if you were to adjust the treble control on a latter, you'd observe that if you turn down the treble, you'd hear a change in the bass. Turn down the treble and you will say good-bye to bass snap with a commensurate loss of detail. It's what happens when tonal balance is out of balance. Conversely, increase the treble level and the bass will become more energized as leading edge transients are emphasized. No, the difference between the stock and modified Bel Cantos is nowhere near that drastic. Still, this analogy goes a long way toward describing why I believe I hear things over the modified Bel Cantos in the way I do.


Try "Sooner Or Later" from the same Super Tramp disc. There's lots of low level heft, power and detail that adds both drama and excitement. Brass, like high percussion, is sharply focused and very energized without becoming piercing. Like the stock amps, the modders maintain an extremely saturated and almost visual presence that suggests, to a higher degree than any other solid-state amplifier I've ever heard, the physical presence of musicians.


Without question, the modified Level 2s just sound livelier in some systems than the stock amps. Why that is should be obvious by now. Brighter and more forward always does. When bass is projected with greater snap and microdynamic impact, the music's pace seems to pick up as well. These are things that the Level 2 modification unquestionably brings to the Bel Canto's already bountiful table.


As the evaluation period wound down, I looked over my listening notes and realized that I had spent a lot of time putting the amplifiers through a lot of worst-case scenario recordings as opposed to just enjoying them on well-recorded music. The reason for this was that I was already aware of what the stock Bel Cantos major in. It was easy to hear what the modified versions could do and it became my mission to find any downsides to their revisions. Once I'd realized that within the context of a properly matched system, I wasn't going to find any downsides, it was time to listen for enjoyment. One of the recordings I've been listening to of late strictly for enjoyment is Neil Young's Harvest Moon [Reprise 945057-2].Let me tell you, it sounded great. I love the music and the recording has an extremely live feel to it. It sounds like one of those live-in-the-studio recordings and I suspect that it is. Unlike most live recordings, however, all the spatial relationships between the instruments are maintained and each instrument is superbly captured with loads of detail, nuance and texture. Microphone placement may be a bit close for a true live experience but spectral coherence seems absolute and it makes for an exceptional listening experience overall. The amplifiers preserved and presented absolutely everything I enjoy about this disc. There was that tactile presence of the performers and the expansively deep and layered soundstage. The Bel Cantos presented a real sense of muscularity with an uncanny sense of pace, rhythm and timing that was the antithesis of muscle-bound - maybe one of the amplifiers' more assuring attributes. If there's a solid-state amplifier that lets you have more tube-reminiscent cake while allowing you to eat it with the powerful reassurance of solid-state, I've yet to hear it.


The remaining question:
So, have I made a case for the Underwood Level 2 modified Bel Canto e.One Reference 1000 amps being better than stock? I hope not. I don't think they are. Of course, my contention isn't that they are worse either. Unquestionably Chris Johnson knows better than to make a good amp worse. He just made it different. A little different but importantly different. Two great amps with the same great heart yet slightly and importantly different to where each will synergize in a slightly different system. It's not about being better or best. It' about blending into your system. It's about gently nudging your system's sound this way or that - or allowing its path undisturbed. That's what system matching and synergy is all about. Remember too how subjective it all is. You may call the stock version deadpan and the modified version natural and neutral. I may call the stock amps neutral and the modified ones bright. It all depends on one's vantage point, where you are and where you want to go.


As it happens, the speakers I have around here -- the Gallo Ref 3.1s and Thiel CS 2.4s -- respond superbly to the stock Bel Cantos. If I was shopping today, that's what I'd buy - again. Anything that moves these two speakers toward added brightness is moving them in the wrong direction. But on my Ohm speakers or any number of others such as Dynaudios and Morels that you may find a touch on the sweet and stoic side, you'll likely welcome the added energy and snap of the Level 2 modified amps. Ditto if your room is on the overdamped side and sucking the life out of your speakers. Then the modified Bel Cantos will be a great choice. [Following the submission of this review, John reported most excellent compatability between the modified amplifiers and the Hyperion HS-968s, asked for and was granted a 6-week loan extension to use this amplifier pair for the Hyperion review. That's more evidence of the component synergy factor he talked about in this review - Ed.]


Hershey makes both milk and dark chocolate. Only fools debate which one is better. Mostly people just enjoy the option of choice. Maybe it's time for audio manufactures to do the same. In this case, a collaboration between Walter Liederman and Chris Johnson amply demonstrates just how useful having a choice can be. These modified Level 2 amplifiers may not be better in the strict sense of the word but they are different and may just sound better in your system. And that's just fine with me. Viva la differentia!
Underwood Hifi website