Last fall, Murali Murugasu talked with me about the birth of his company, Constellation Audio, which he cofounded with David Payes in 2010. “We knew that to succeed, we would need to bring something new and special to the marketplace,” he said. Yet if you take a quick look at Constellation’s Revelation Taurus Mono power amplifiers ($39,000 USD/pair), and the Revelation Pictor preamplifier ($18,000) with optional DC filter ($5000) reviewed here, you might wonder how that could possibly be true -- from the outside, they look like typical audio separates.
But if you’ve read my review of the Revelation Taurus, published in December 2017, you know that Constellation products include some interesting design wrinkles that result in sound quality that’s anything but ordinary. The same is true of the Pictor, with or without DC filter. Technically and sonically, it’s unlike any preamp I’ve reviewed.
As I wrote last December, “Constellation Audio makes four series of electronics -- ascending in price from entry level, they are the Inspiration, Revelation, Performance, and Reference lines. The models in each are cut from the same technical and visual cloths.” In the Revelation Pictor, Constellation has combined elements of their current preamp models one step above and below the Revelation line: the Performance Virgo III ($32,000) and the Inspiration Preamp 1.0 ($9900). (Aron Garrecht reviewed the Inspiration Preamp 1.0 for SoundStage! Ultra in June 2016.) The family resemblance is strong, and a lot of trickling of technology -- down and up -- has been going on.
Constellation’s promotional copy states that the Pictor “uses the same core circuit topology as Virgo III, and a few minor changes aside, the same separate power supply. The main difference is that Pictor has fewer inputs.” The Virgo III has four balanced inputs (XLR) and four single-ended inputs (RCA), the Pictor three of each. Both have two sets each of balanced (XLR) and single-ended (RCA) outputs.
About that separate power supply: The Pictor’s measures 17”W x 2.75”H x 14.5”D. On its rear panel are the main power switch, and three umbilicals that attach it either to the preamp proper or the optional DC filter. For the ultimate in isolation, this power supply actually comprises three individual power supplies: one each for the left and right channels and the control circuitry. Each supply has its own umbilical, those cords long enough (about 1.5m) so that the case can be placed on a separate shelf -- or, as I did, under the DC filter, on which sat the preamp itself. The filter and power supply are the same size, and the result was one big stack 10.75”H. While some might find an external power supply a bit of a hassle because it means one more big box to find room for, placing the power-supply circuitry far from the sensitive audio circuitry can reduce noise.
The DC filter also has three umbilicals, also 1.5m long. These plug into the filters, and the filters’ cords into the preamp. Per Constellation, “Our optional DC power filter augments the already impressive power storage and filtration in the stock power supply. The added peak output and filtration from the DC filter allows Pictor to achieve even better dynamics with even lower power supply noise.”
The main case -- the Pictor itself, through which the audio signals pass -- measures 17”W x 5.25”H (including feet) x 15”D. Protruding from the faceplate is a smaller plate containing an elegant central touchscreen between large Balance and Volume dials, the latter operating in increments of 0.5dB from -99.5dB to 0dB. Although increments of half a dB are far coarser than the 0.1dB offered by my reference preamp of the last few years, Simaudio’s Moon Evolution 740P ($9500), I never found myself wanting a volume level in between two of the Pictor’s 200 possible volume levels. I also found that, from extremely low to very high volumes, aural images never wavered, which indicates excellent channel tracking.
On the underside of that subplate are five discreetly mounted pushbuttons that, with the options on the touchscreen, offer full control. The most frequently used functions -- volume control, channel balance, muting, phase inversion, input selection, power on/off -- are duplicated on the remote control (supplied), but mostly I used the touchscreen and pushbuttons.
Press Setup on the touchscreen to set such things as a maximum and minimum volume level for each input, a feature I’ve always found useful. I like to set a maximum volume level for each input so that no one can carelessly turn up the volume too high and blow up my speakers -- a concern with the Taurus Monos, each of which can put out more than 500W into 8 ohms. The volume-level setting is also how you set up the input you choose to use as a home-theater pass-through: set the max and min volumes to the same level. There’s no fixed volume level you must use for HT pass-through; I chose -25dB, which, as you’ll read below, should correspond to unity gain. For those using the Pictor with a home-automation system, there are RS-232 and USB connectors on the rear panel, in addition to a 12V trigger output to kick-start an amp; the USB port is also used to update the Pictor’s software.
Like the Taurus Mono, the Pictor comes in a whitish-gray finish with a suede-like texture on all surfaces but the rear panel. The power supply and DC filter are finished this way only on their front panels; their sides and tops comprise a single piece of folded, brushed aluminum finished in silver-gray. The whitish-gray is the only finish available, which is fine with me; I found the Pictor’s overall looks just as attractive as I found the Taurus Mono’s -- and not only the finish, but the preamp’s size, shape, and cosmetic flourishes, such as the two ridges that run the height of the front panel and then to the rear of the top panel. (When the power supply and DC filter are stacked, their front-panel ridges vertically align.) But while I thought the Taurus Mono’s build tolerances could have been a bit better, particularly in the rear panel and seams, I didn’t have that complaint about the Pictor -- the seams of my review sample looked tight, and its rear panel didn’t look as kludgy as the Taurus’s.
The main difference between the Constellation preamps’ circuitry and that of other companies’ preamps is Constellation’s Line Stage Gain Module, “a fully balanced topology, with separate mirror-imaged circuits to amplify the positive and negative halves of the audio signal. To assure clear reproduction of even the subtlest details, we use a servo circuit that continuously monitors and maintains the positive/negative signal balance. Use of ultra-low-noise field-effect transistors (FETs) assures that Pictor’s outputs emit pure music and nothing else.”
Constellation recommends that any of their preamps be connected to any of their amps via the preamp’s balanced outputs and balanced cables and the amp’s Direct inputs, all those connectors being XLRs. This is because the Line Stage Gain Module provides enormous gain: about 25dB (hence my pass-through setting of -25dB). As a result, the Direct inputs bypass, in each amp, the gain stage that “normal” preamplifiers would need. Using the Direct connection means less amplifier circuitry in the signal path, resulting in lower noise and distortion. So that’s how I connected the Pictor to the Taurus Monos.
To put 25dB of preamp gain into perspective: The preamplifiers I typically use provide less than 15dB of gain, and some of them less than that -- EMM Labs’ Pre2 ($15,000), which I long used, is specified to provide 12dB, and the gain spec of Simaudio’s Moon Evolution 740P ($9500) is only 9dB. But a preamp that provides as much gain as the Pictor does can cause compatibility problems with some other companies’ amplifiers, as I discuss below.
In addition to Constellation’s Revelation Taurus Mono amps, I also hooked up their Revelation Pictor to the balanced inputs of Eximus’s S1 stereo amplifier ($2500) and JE Audio’s VM60 monoblocks ($6600/pair). The S1 is a class-D design claimed to put out 125Wpc into 8 ohms; the all-tube VM60 is specified at 60W into 8 or 4 ohms. Both cost much less than the Pictor and are thus unlikely ever to be used with one, but they’re so different from the Taurus Monos in circuit design that I wanted to test their compatibility with the Pictor. Loudspeakers were GoldenEar Technology Triton References ($8499.98/pair), Dynaudio Special Fortys ($2999/pair), or Revel Ultima2 Salon2s ($21,998/pair), all connected with Siltech’s Classic Anniversary speaker cables. I also used an EMM Labs DA2 Reference DAC, which has no volume control.
All DAC-to-preamp connections were with Crystal Cable Standard Diamond balanced interconnects, and all preamp-to-amp connections were with Audience Au24 SX balanced interconnects. Digital files were played by a Samsung laptop computer running Windows 10, Roon, and Tidal’s desktop player; the laptop-to-DAC connection was via an AudioQuest Diamond USB link. Preamps and DACs were at first plugged into a Shunyata Research PS8 power distributor, and the PS8 into a dedicated wall socket, with Shunyata’s Venom HC power cords. Later in the review, I swapped out the PS8 for a Shunyata Denali D6000/S distributor and used the same cords. The stock power cords of all amps were plugged into another PS8, itself plugged into another dedicated wall socket with another Venom HC cord.
Sound -- DC filter in
First, I hooked up the Revelation Pictor to the Eximus S1 stereo amp, in turn connected to the GoldenEar Triton References. Immediately after powering it all up, I put my ear to one of the Tritons’ ribbon tweeter and heard a hiss as faint as I’ve heard from the best pre-power combos I’ve had here -- a good start. While the S1 has never been close to a state-of-the-art amp, I’ve always found its sound to be clean from the lows through the highs, if sometimes a bit lean, which can thin out voices. With the Pictor, the S1 sounded the best I’ve heard it -- slightly clearer, and able to project more spacious soundstages, along with better delineation of musicians on those stages. I really liked listening to Van Morrison’s alto saxophone in “Spanish Steps,” from his Poetic Champions Compose (16-bit/44.1kHz FLAC, Mercury/Tidal) -- there was a good balance of texture and smoothness from his instrument on a very wide soundstage, and with a feeling of spaciousness I never knew the S1 could convey. What most impressed me was that the midrange was slightly fuller and smoother than I’d previously heard from the S1, which made voices sound more real. The sound of Glen Hansard’s voice in “Bird of Sorrow,” from his Rhythm and Repose (16/44.1 FLAC, Anti-/Tidal), was, like Morrison’s alto sax, a fine blend of texture and smoothness. What seemed lacking with this combo were the smallest musical details; while the resolution was good, it wasn’t sky-high. Still, the sound was impressive.
Next in were JE Audio’s VM60 tubed monoblocks, again with the Triton References -- and here a problem arose. With no music playing, I could hear hiss from the speakers from my listening chair, about 8’ away. Music masked the hiss at typical listening levels, but at low volumes it was way too audible. Morrison’s “Spanish Steps” still sounded smooth and textured, but now I heard more hiss from the electronics than air in the recording space.
Of course, I’d expect more hiss from the VM60s -- tubes are inherently noisier than transistors -- but this was a lot more noise than I’d ever heard from these amps. Aron Garrecht had the same problem when he hooked up the Inspiration Preamp 1.0 to his Simaudio Moon Evolution W-7M monos, which are entirely solid-state: “When the Preamp 1.0 had completed its check and was fully powered up, it presented me with another surprise: noise. Although much quieter than what I heard with the Constellation’s home-theater bypass at full tilt, I could still hear a faint hiss from my speakers from almost 3’ away.” His hiss wasn’t as bad as mine, but still, something was amiss . . .
As far as I could tell, Aron’s and my hiss problems were caused by hooking up a preamp and a power amp that both had abnormally high gain. I’ve found that most power amps provide between 26 and 28dB of gain. The measurements of the Eximus S1 that Bascom H. King did for us show that its balanced inputs produce a below-average 22.5dB of gain, which apparently is what the Pictor (and, I assume, the Preamp 1.0) likes. We didn’t measure the VM60, but when I heard all that hiss, I contacted JE Audio. Designer John Lam confirmed that the VM60’s gain exceeds 30dB -- above average. The Simaudio W-7M’s specifications reveal a high gain of 31dB, which helps explain why Simaudio’s preamps have lower-than-average gain. In short: A power amp with high gain might still play music fine with a Constellation preamp, but that combination is likely to produce a lot of noise, as Aron and I found. If you’re going to partner the Pictor with another manufacturer’s amplifier, compatibility of gain will be key: 1) check the amplifier’s gain; and, most important, 2) try the combo before you buy.
With the Pictor driving the Tauruses, the hiss vanished. I had to press an ear right against the tweeter of a speaker -- GoldenEar, Dynaudio, or Revel -- to hear even the faintest hiss, and from a few inches away I could hear nothing. I can’t be 100% sure that the Pictor-Taurus combo is the quietest I’ve ever had in my room, but it’s definitely one of them.
When I played music, I heard what Aron had heard from the Inspiration Preamp 1.0: transparency in spades. I don’t mean just neutrality -- that the lows through the highs were in perfect balance, with an absence of frequency-response-related colorations. What I mean by transparency is that the sound was so clear and unobstructed that I could hear every musical nuance of every recording I played. It was similar to what Aron said of the Preamp 1.0: “What was abundantly audible, regardless of the recording played, was how transparent the Preamp 1.0 was even when not paired with a Constellation amp. Microlevel details consistently flowed out of my speakers with ease, as if sucked out of the drivers by my room rather than pushed out by an amp.”
Where I disagree with Aron is his use of the word flowed, which understates what I heard. Projected was more like it, particularly when I was playing a recording that had well captured the sound of an acoustic space. Musical details didn’t seep into my room, they took it over, most noticeably when I was using the Triton References or Ultima2 Salon2s, both of which are big speakers capable of filling large listening spaces such as mine. When I played “Spanish Steps” through the Pictor-Taurus combo, the soundstage was considerably wider and deeper than with the Eximus S1, while instruments on that stage were defined better than I’d heard them before. But what struck me as uncanny about the sound was how much more information I could hear between and among the musicians -- there seemed to be more air, as opposed to just nothing.
I heard similar things with “One Step Up,” my favorite track from Bruce Springsteen’s Tunnel of Love (16/44.1 FLAC, Columbia). The album was recorded digitally, which, compared with his seven previous albums, seems to have given it a more dynamic and visceral sound. However, I’ve always found this album lacking in soundstage depth and low-level details, as if some subtleties of the music were lopped off during recording. No component can bring back what’s not there in the recording, but with the EMM Labs DA2 Reference DAC connected to the Pictor and Taurus Monos driving the Salon2s, the soundstage was not only the deepest I’ve heard from this track but also the most detailed, filling the space between Springsteen’s front-mixed vocal and Patti Scialfa’s backing vocal, the latter positioned off to one side and behind him. In “Ain’t Got You,” in which Springsteen’s voice and guitar are strangely panned far right and the other instruments far left, with nothing in the center (reminiscent of early “stereo” releases), I was taken with how much space and air I could hear around Springsteen’s voice and the various instruments -- more than through any system I’d played it through before.
With recordings containing far more sense of acoustic space, the Constellation components’ adeptness at revealing spatial details was even more profound. Willie Nelson’s little-known Teatro (16/44.1 FLAC, Island/Tidal) was produced by Daniel Lanois and recorded in an abandoned movie theater in Oxnard, California. When I played “Everywhere I Go” through the EMM Labs DA2 Reference, Constellations, and Salon2s, the speaker end of my room was transformed into a space that sounded much larger. Nelson’s voice and guitar were closest to the front of the stage and sounded ultradetailed, while the drums, which enter at 0:54, were reproduced solidly in the far left rear of the stage. But it wasn’t just Nelson in one place and the drums in another -- there was so much more air between and joining their sounds than I’d ever heard before.
The percussion instruments in “My Own Peculiar Way,” also from Teatro, weren’t quite as visceral, probably because they sounded as if placed even farther back on the stage; the resulting illusion is of a space even larger, with greater distances between instruments, all reproduced and easily audible in my room. The reproduction of spatial information and minute musical details by the Constellation combo of Pictor preamp and Taurus Monos was the best I’ve heard.
Sound -- DC filter out
In her song “Big Yellow Taxi,” Joni Mitchell sings “you don’t know what you’ve got / Till it’s gone” -- a phrase I’ve found applicable to comparisons of audio components. Sometimes, when I insert a new component, it’s hard to hear an improvement; I hear any improvements a lot more clearly when I later remove that component from the system. That’s why I began listening to the Revelation Pictor with Constellation’s DC filter in circuit: I first wanted to hear what the Pictor, power supply, and DC filter could do together, before I removed the filter to hear what, if anything, was lost.
I didn’t think I’d hear much of a difference when I removed the DC filter, and at first I didn’t. With the Pictor feeding the Tauruses without the filter, the level of tweeter hiss with no music playing didn’t change. Then, with music playing, there was absolutely no change in tonality -- it was still dead neutral throughout the audioband. There were also no changes in large-scale dynamics, or the feeling of effortlessness at high volume levels that the powerful Taurus Monos provided.
It was only when I listened at moderate to low volumes that small but important differences began to emerge. The piano in “Constellations” and “You Be the Leaver,” from singer-songwriter Jim Cuddy’s Constellation (16/44.1 FLAC, Warner Music Canada/Tidal), sounded just a bit less incisive without the filter, as did Cuddy’s voice -- his subtle inflections didn’t inflect as much. These weren’t big differences, but they were obvious, and consistent as I switched the filter in and out. I also noticed a reduction in spaciousness around Cuddy’s voice and piano. With Cuddy’s bluesier, more rock-oriented tracks, such as “Hands on the Glass,” I could hear no difference in terms of incisiveness or the amount of air around individual musicians, but the entire soundstage was a bit less deep, which made the overall sound not quite as spacious; also, the aural images of instruments and voices weren’t quite as well defined.
When I played Dua Lipa’s Live Acoustic EP (16/44.1 FLAC, Warner Bros.) from my computer’s hard drive, the piano that accompanies her in “New Rules (Piano Acoustic)” didn’t sound quite as spirited, and the spaces around her voice and the piano weren’t as well defined without the DC filter. The sound of the guitar in “I’d Rather Go Blind” remained unchanged when I removed the filter, but Lipa’s voice didn’t sound quite as smooth or as clean. And, as with Cuddy’s voice, the tiniest inflections weren’t as strong without the filter.
The audible effects of Constellation’s DC filter were subtle but definite improvements; the only downside is the additional $5000 it costs. In the context of a super-high-resolution system for which cost is no object, I consider it a necessary companion for the Pictor.
I compared the Constellation Revelation Pictor with two other preamps: Simaudio’s Moon Evolution 740P ($9500) and Hegel Music Systems’ HD30 DAC ($4800), both of which support balanced connection. The Hegel’s digital volume control meant that I could use it as a preamp straight into the Taurus Monos, or with the volume control defeated and straight into a preamp. The EMM Labs DA2 Reference DAC was always connected to the 740P or Pictor.
Unlike the Revelation Pictor, the Simaudio 740P and Hegel HD30 don’t produce enough juice to drive the Revelation Taurus Monos through those amps’ Direct inputs. I had to connect those preamps to the Tauruses’ standard balanced inputs, which send the signal through each amp’s gain stage. Still, this let me hear how more typical preamps might mate with the Tauruses. Most of these comparisons were done with the Dynaudio Special Forty speakers, which lack bass below about 40Hz, but whose resolving abilities above that make it easy to hear differences in upstream components.
First, I compared the Simaudio 740P and the Constellation Pictor, using both the Hegel HD30 (as a DAC only) and the EMM Labs DA2 Reference DAC. Although the DACs’ sounds differed slightly, certain qualities were common to both, which made it possible for me to suss out what the preamps were doing. That said, I’ve always admired the 740P for its high level of transparency -- it gets out of the way and lets the music flow through unadulterated, retaining high levels of detail. That’s what it did here -- but compared to the Pictor the Simaudio sounded a little thin, which I noticed mostly with voices. The 740P was also a touch wispy in the highest frequencies, which made some selections teeter toward the bright. The Simaudio’s soundstages were also slightly less spacious -- the Pictor-Taurus combo’s strong suit. Overall, the differences in sound between the Constellation and the Simaudio were considerably smaller than the difference in price -- $23,000 vs. $9500, respectively -- but there was no question: the Pictor sounded better. For the 740P Simaudio offers a standalone power supply, the Moon Evolution 820S, which I’ve reviewed. The 820S sells for $8000, which reduces the difference in price to $5500. But as I’d already returned my review sample of the 820S to Simaudio, I couldn’t make that comparison. Knowing the small difference the 820S did make in the 740P’s sound, I suspect it would have helped the 740P produce soundstages that were ever so slightly more spacious. Nonetheless, I think the combo of Pictor, DC filter, and Taurus Monos would still beat the 740P-820S pairing -- the Constellations had a synergy I’ll touch on below.
When I tried using the Hegel HD30 as a preamp straight into the Tauruses, the results were more interesting and surprising. The HD30-Taurus combo sounded vivid, highly detailed, and a touch more exciting -- Van Morrison’s alto sax in “Spanish Steps” had a bite and attack that were just a bit blunted when the HD30’s DAC section ran through the 740P and into the Tauruses. Likewise, Glen Hansard’s voice had just a bit more presence and detail with the HD30 connected straight into the amps.
When I listened to the HD30’s DAC through the Pictor, I expected to lose some detail, and some of that incisiveness and attack -- but I heard no differences in those areas. Instead, there were only gains when I added the Pictor: wider, deeper stages, and a more enveloping and involving sound overall, even through the little Special Fortys.
In short, my system sounded a bit better with the HD30 directly feeding the power amps, vs. the Hegel’s DAC going through the Simaudio 740P preamp. But that wasn’t the case with the Pictor, which leads me to believe it had to do with the quality of the Constellations’ circuit designs, and a synergy of the Pictor and Tauruses when connected through the amps’ Direct inputs. On the other hand, the Hegel HD30 costs only $4800; if you want the Revelation Taurus Monos but can’t afford to buy the Revelation Pictor at the same time, the Hegel will provide a heck of a good start -- a better start, I think, than would sticking someone else’s preamp in between.
Ultimately, the HD30’s sound into the Pictor was bettered by the EMM Labs DA2 Reference DAC into the Pictor, but at a price -- the DA2 Reference costs $25,000. What robustly confirmed the DA2 Reference’s superiority of sound was when a software update was released in the middle of my listening for the Taurus Monos review. Whereas, pre-update, the DA2 Reference sounded a tiny bit better than the Hegel HD30 in various areas, the update resulted in marked improvements in resolution and, thus, soundstage spatiality, image specificity, and overall smoothness and ease -- not unlike the levels of all of these provided by the Constellation separates. I’m sure those improvements in the EMM would be clearly audible through any good preamp, but when I heard them through the Pictor and Tauruses, which by then were driving the Revel Salon2s, I did a double-take. Never had I heard the Salon2s sound as good in my room.
Any pairing of preamp and power amp, particularly if they’re made by different companies, must be heard before buying -- and that goes double for a preamp that produces as much gain as does Constellation Audio’s Revelation Pictor. The combination may be magical, or it may not work well at all. Beware.
But if you plan to or have already bought a pair of Constellation’s Revelation Taurus Monos, I see no reason why you shouldn’t also buy a Pictor. I found their sonic synergy so strong that I don’t see why Constellation doesn’t offer special interconnects for them at a nominal price, to encourage customers to buy and use them together. The sound of the Pictor-Taurus-DC filter combination wasn’t just special -- to my ears, its spaciousness, resolution, and smoothness were spectacular enough to be considered the state of the art.
. . . Doug Schneider
Constellation Audio Revelation Pictor Preamplifier and Optional DC Filter
Prices: Pictor, $18,000 USD; DC filter, $5000 USD.
Warranty: Three years parts and labor.
Suite 1, Level 6
580 St Kilda Road
Melbourne Vic 3004
3533 Old Conejo Road, Suite 107
Newbury Park, CA 91320
Phone: (805) 201-2610