September 2003Orpheus Laboratories Three S Stereo Amplifier
by Doug Schneider
The people at Switzerland-based Orpheus Laboratories appear poised to make quite a splash in the high-end audio world. If they succeed, theyll do it by not only making good-sounding electronics. Theyll also have bucked some trends and punched holes the size of Buicks into some conventional audiophile wisdom.
To say the least, Orpheus products are unique. The Orpheus One digital-to-analog converter features the Anagram Technologies ATF (Adaptive Time Filtering) 24/192 upsampling engine. Anagram, you see, owns Orpheus Laboratories and makes "high-performance digital signal processing solutions" -- not full components, but hardware and software like ATF that can be incorporated into other companies products. Indeed, that leg of the business has had considerable success. Today you can see the ATF upsampling module implemented in a number of high-end CD players and digital-to-analog converters, the most famous likely being Audio Aeros Capitole 24/192 CD player, which uses a customized version of ATF that Audio Aero calls STARS. Of course, Anagram products get used in Orpheus products, too.
Then theres the Two multichannel preamplifier -- a high-resolution preamplifier that's user-configurable between two and six channels. In November, 2002, Jeff Fritz praised it to the high heavens for how neutral it sounded, as did I, and it gained a well-deserved Reviewers Choice nod, along with the SoundStage! Network Edge of the Art award for 2002.
But what could Orpheus and Anagram do with a power amplifier -- a solid-state power amplifier at that? The Orpheus Laboratories Model Three M 150W monoblocks ($8400 USD per pair) and the Three S stereo amplifier ($4600), the subject of this review, include the Anagram Technologies Power Loop -- a unique circuit placed in the output stage of the amplifier that purports to turn what would be a normal solid-state amplifier into one that delivers constant power into any type of speaker load. The Three S is rated at 40Wpc into 16, 8, and 4 ohms. This is unusual for a solid-state amplifier, which will usually deliver less power into 16 ohms than into 8, and more power into 4 ohms.
The styling of the Three S (and Three M) is amazingly simple -- too simple, perhaps, for those who enjoy giant bulky devices with incredibly thick faceplates and massive heatsinks jutting from the sides. But I like the way this amp looks -- then again, Im not one of those people who has to have something that looks like a car engine resting on my floor to bolster my audiophile status.
The faceplate is 19" wide, but only 1-3/4" high, and from front to back the amp is 15". There are no external heatsinks. The unobtrusive size and appearance, no doubt, is likely the reason that some audiophiles think that the Orpheus amps are digital switching designs. Theyre not.
When you pick the Three S up youll notice how surprisingly heavy it is. Its weighted mainly to the front, where the large but shallow transformers sit. And when the amp plays, it gets hot -- hot enough that I quizzed Orpheus Labs about this, wondering if the amp needed lots of "breathing room." It doesn't. In fact, Orpheus gave me the go-ahead to stack the other Orpheus components I had in-house on top of the amp -- exactly how they do it at their factory! I was surprised, but I did it, and I never encountered a problem. However, reviewer stress-testing isnt necessarily something the user at home should do. If you buy a Three S, I recommend giving it some breathing room, or at the very least put the amplifier on top, or near the very top, of your stack of components. Why build up excess heat if you really dont have to?
The backside of the amp is pretty conventional: single-ended and balanced inputs, a dual set of speaker binding posts, an IEC receptacle for a detachable power cord, and the on/off switch.
Now things get a little trickier
The Three Ss power rating is 40Wpc -- not all that great for a $4600 amp and not likely to impress those who buy watts by the dollar. But as I said, the interesting thing here is that Orpheus claims 40Wpc regardless of the load. Understanding this, though, is critical to successfully implementing the amp in your system. There are, after all, implications that consumers need to realize.
Delivering constant power is done using the Power Loop, a feedback-type circuit that monitors the output of the amplifier against the input needs of the speaker, and faster than Winona Ryder can stuff clothing into her purse, voltage and current get adjusted. As a result, the amplifiers output impedance will vary, too. With a conventional solid-state amplifier, voltage remains constant.
This explanation is deliberately oversimplified (I recommend reading Orpheus Labs' literature or website to find out more), but its enough to raise a simple question: Why do things this way? Orpheus Labs says that adjusting the output voltage and current results in better control of the speakers drivers, and this, they say, results in better transient response. And transients, they point out, are what music is all about. So why doesnt everyone do this? Because, as I said, Orpheus is bucking some trends -- most notably the way were led to believe an amplifier should work.
All other solid-state amplifiers I know of are designed to deliver constant voltage, with output impedance as close to zero as possible. And, not surprisingly, almost all speakers are designed to be driven by an amplifier that delivers constant voltage. Florian Cossy, head of research and development at Orpheus and Anagram, readily admits that the solid-state Three S and Three M behave more like tube-based amps that have a high output impedance. However, the similarity ends there because Florian doesnt buy into the notion of actually using tubes, calling them "distortion devices."
But because most speakers are designed for amplifiers with constant voltage and a very low output impedance, they wont react the same when fed constant power. In fact, their frequency-response curves will vary in a way that correlates with the speakers impedance curve -- just like those high-output-impedance tube amps. So even those who contend that all solid-state amplifiers sound the same might be forced to back off from that stance when they encounter the Three S and Three M because, if what Orpheus Labs says will happen does happen, its quite easy to demonstrate through measurements how the acoustical output of a speaker designed for an amplifier that delivers constant voltage will be altered using an amp like the Three S and Three M.
"So isnt that bad?" That was the next question I posed to Florian, and he believes that the frequency-response deviations are minor compared to what a real room can do to the output of a speaker (room gain, for example, can bump a speakers output at various frequencies astronomically), and, he believes, the frequency-response compromise is offset by the improvement in transient response.
The only thing I could do at that point was listen to the Three S.
Before I get started
Discerning this amplifiers sound is a challenge because it is dependent on the amp's interaction with the speaker. As I noted, constant power will cause response variations in the speakers output that wont be present in a conventionally designed solid-state power amplifier. Comparing two amplifiers is difficult enough. But comparing two amplifiers when there is a frequency-response variation with one that differs from speaker to speaker is close to impossible. Therefore, does it make sense to compare the Three S to a tube amp? Not really -- but for even more reasons. Even the all-amplifiers-sound-the-same group normally holds their arguments within the limits of solid-state designs, readily conceding that tubes have a flavor, or "sound," if you will. I love tube amps. I wont dismiss them like some will, but Ill be the first to admit tube-based amps vary sonically to a far greater degree than solid-state amps. The Three S sounds different from a tube amp, thats for sure, but for a whole lot more reasons than just one.
But dont get the idea that the Orpheus Three Ss sound varies so greatly that same music played through one speaker sounds completely different played through the next. The folks at Orpheus Labs are right: Frequency-response variations, when you factor in the room, are not quite as cutndried as some may think. Still, it must be noted that I detected some variation with speakers that were audible enough that I couldnt discount them. In the end, then, I have to confine my review to my experience with the amplifier, along with description of some basic sonic characteristics of the Three S that help to define its sound and were shared among the speakers I used.
I used the Three S with the Orpheus Two multichannel preamplifier and One DAC (with my Theta Data Basic as a transport). A variety of review speakers included Verity Audio Tamino, Song Audio Type II Silk DM, Ruark CL10, and Ascend Acoustics CBM-170. Analog cables were either from Nirvana (S-L) or Nordost (Valkyrja); the digital cable was i2Digitals X-60.
The Tamino was quite telling about the amplifiers output capability. The Power Loop module is one thing to consider, but the 40Wpc output was yet another. I feared the Three S would die trying to drive the Tamino, which has been a tough load for a few amplifiers Ive had here. (I suspect quite low impedance, although I dont have measurements for this speaker here to back that up.) As a result, the best partners to date have been beefy solid-state units: the Perreaux 200ip and Simaudio i-3 integrateds rated at 200Wpc and 100Wpc, respectively. Those amplifiers grabbed the Taminos like vices, turning them from the mushy mess that some amplifiers produced into quite an open, transparent, and lively sounding speaker.
And the Three S? It was able to do the same thing in a way that surprised me. There was no strain and certainly no sense of pain coming from it -- nor was there a hint that this is a low-powered amplifier. From weighty and gutsy orchestral pieces like Carmina Burana [Telarc 80056] to hard-edged and gutsy rock-type affairs like Steve Earles Jerusalem [Artemis 751147], the Three S maintained a solid grip that resulted in deep, tight, and sometimes thunderous bass, along with rich, controlled, and textured midrange frequencies. There was also loads of details amidst a top end that was airy, clean, and wonderfully extended. Voices and instruments hovered in space, carved from the mix, and the bass was so authoritative that I was impressed by how muscular this relatively small amp could sound. However, Im apprehensive to say something like the Three S has stronger bass than some other amplifier. There is, after all, the Power Loop in the equation. Many speakers have rising impedances in the bass region that could account for a large part of what would be heard. Therefore, on that final note, I will conclude inconclusively, that the bass from the Taminos was impressive.
And while controlling the speaker is one thing, achieving high SPLs is another. In my smallish room, I did try to tax the Three S to its limits -- but surprisingly, I never succeeded. My room and I gave out before the Three S did. This isnt to say that the Three S is some sort of magical powerhouse, mind you. Orpheus Labs does offer the 150W M version for a good reason -- some people will need more power. How loud you need a speaker to play will depend on your room size and speakers sensitivity. My room isnt all that big, and the speakers I was using were of average sensitivity. What this does prove, though, is that 40 watts can get you quite far provided the amplifier is beefy enough to wrestle with any speaker load.
The Three S exhibited another strength that was consistent from speaker to speaker: astonishing transparency and cleanliness. Like its companion the Two preamplifier, there is starkness to the Three S's presentation thats far more significant than, say, simply wiping a window clean, or lifting a "veil." Its like taking a rock and breaking through the window to see a crystal-clear view of whats outside. The Three S sounds so clean its as though it's not there.
Glenn Goulds A State of Wonder: The Complete Goldberg Variations (1955 & 1981) [Sony Classical 87703] is a surprisingly pristine-sounding CD set -- great older recordings now polished up with state-of-the-art remastering. Here the Three S shows its abilities and lets you know why it costs what it does -- and why you shouldnt necessarily buy your watts by the dollar. Goulds piano hovered in space, nothing obscuring it, amidst a ton of detail. From the lows through the highs, the Three S sounds utterly clean -- crystalline is perhaps even better. There isnt a hint of grain, hash, or grunge. What you get is an exceedingly pure, see-through rendering of the recording -- and the Three S does this without sounding fatiguing, as some solid-state amps can.
In fact, sometimes when I tire of the zippiness inherent in some solid-state designs, I turn to something like the all-tube Zanden Model 600 for its rather romantic take. The Zanden isnt as airy as the better solid-state amps, sacrificing a bit up top for a less-fatiguing sound, but it can sound so much easier on the ears. Now I turn to the Three S, too. The Three S cant match the 600s richness, particularly through the midrange, but its top end is fully extended without going over the edge. And thats the key to the Orpheus Three S. Its not how it looks or how much power it delivers; its how refined it sounds -- or doesnt sound, depending on how you look at it.
But thats not to say that the Three S is without fault -- depending on your speakers it can be, well, a little odd. And although I cant necessarily confirm it definitively, I suspect it has to do with the unique topology it employs, which includes the Power Loop circuit. Thats why you have to be careful with what speakers you match it with.
Whereas the Taminos and the Three S mated quite successfully -- as did the CBM-170 and Song Audio Type II Silk DM -- the results with Ruarks CL10 were mixed. Bass and highs from the CL10s were fine: clean, tight, and articulate down low; clean, clear and infinitely extended up top. These things remained consistent from speaker to speaker. But still, the pairing wasnt quite right in the midrange. I remember playing Norah Jones Come Away with Me [Blue Note 32088] and finding her voice and portions of her piano leaping out at me too much. The CL10s already have a front-row perspective, but this was putting me right up to the stage.
Weve measured the CL10, and these measurements will perhaps help to explain things. Even driven by a normal solid-state amplifier, the CL10s have a peak, both on and off axis, starting at around 600Hz and extending a little past 1kHz. In my review of the speakers, I noted the speakers slightly forward balance. Surprisingly, though, its not really objectionable -- the CL10s sounded so clean that when they presented things like voices in a little more forward manner, the sound was still quite good and lively. However, with the Three S it was even more forward than that.
Strange? Not really. Looking at the impedance measurement for the speaker shows an additional rise starting in that same area, but extending upwards to about 2kHz. That means that harnessed to the Three S, you get the normal "bump" in the midrange thats inherent in the CL10, and then, likely, an additional bump in that same region and beyond. As a result, the CL10 goes from a little forward, to even more forward. Too much of a good thing? With the Three S, yes.
As I mentioned, the unique operating nature of the Three S makes an apples-to-apples comparison with any solid-state amp almost impossible. However, there are some things that can be said about the Orpheus amp in relation to other amps, perhaps to put into perspective why someone might pay so much for a relatively low-powered amplifier.
The Perreaux 200iP I mentioned is priced about $2000 less than the Three S, and the i-3 almost $3000 less -- and they are integrated amps to boot! In terms of power output and features, the Three S cant compete. The Three Ss strength, though, is its refinement. The 200iP and the i-3 sound great and are worth every cent of their asking prices -- and then some. But when you move to the Three S, you hear more detail and clarity in the midrange, along with a top end that is so squeaky clean and extended, without even the remotest hint of hash, that the differences hit you square in the face.
I played the soundtrack to The Mission [Virgin 90567-2], a long-time favorite of mine that features large-scale choral works. The speaker end of my room was flush with voices, each wonderfully delineated. The stage was precisely set, and the minutest details were easy to discern. The Three S gives a high-rez presentation, but without any sizzle or bite.
As Jeff Fritz has done, I recommended the Orpheus Labs Two multichannel preamplifier with plenty of enthusiasm. And Im just as enthusiastic about the Three S in a number of ways. The Three S is only modestly powered, but its gutsy in a way that makes you forget its power rating. More importantly, though, its one of the most pristine-sounding amplifiers Ive heard -- tube or solid state. It's squeaky clean to the max, transparent and detailed as anything, and most certainly never fatiguing. Its $4600 price isnt cheap, but this amplifier is ultra-refined-sounding, and thats what you are paying for.
However, I have to temper my enthusiasm some. The Three S, more than any other solid-state amplifier Ive used, has to be matched carefully to the speaker with which you want to use it. Your experience will likely vary somewhat from speaker to speaker, as it did for me. The Three S is certainly unique, and the guys at Orpheus Laboratories are bucking some trends with their designs, but theres a bit of a caveat to doing that. Still, dont let reservations dissuade you from checking this amp out -- although you must try before you buy.
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