Rogue Audio Sphinx integrated amplifier Page 2

Whenever my system is suddenly producing copious amounts of tight bass, I feel a need to gorge myself on it until I can't stand it anymore. So I reached for Daft Punk's Homework (CD, Virgin) and played it through twice. Still bingeing, I played Sunn O)))'s Black One (CD, Southern Lord SUNN50) all the way through. Then I tried the bass orgy of Aphex Twin's I Care Because You Do (CD, Sire 61790-2). King Sunny Ade and His African Beats' Juju Music (LP, Island MLPS 9712) immersed me knee-deep in waves of pulsing bass guitar. The Sphinx supported the party mood, the low power of the talking drums, and the texture of the dream-inducing keyboards on this album. Finally, ready to purge, I headed for the louche bars of Montparnasse.

The first time my mind really focused on the Sphinx's midrange was while listening to "La Vie d'Artiste," by the Parisian chanteur Leo Ferre, from Chansons de Leo Ferre, a 10" LP from 1953 (Le Chant du Monde LD-M-4022). The gentle piano and the loping, whispery rhythms of Ferre's singing were there for me to enjoy, his closely miked voice quivering and fluttering in air between the speakers. For a minute I listened critically instead of romantically, whereupon it became clear that the Sphinx was reducing the candlelit color and glowing vibrato of the sounds of both voice and piano—no more wet cobblestones, no fog surrounding those Paris gaslights. But, bloody French hell—this is a $1295 integrated, not some million-dollar drug substitute.

After Leo Ferre, I had no choice but to play some recordings by what Jean Cocteau described as a "terrifying little sleepwalker who sings her dreams to the air on the edge of a roof": Édith Piaf. Wondering what the Sphinx would do with the courage and big spirit of the Little Sparrow, I played what many call her last lament: "Non, je ne regrette rien (No, I Regret Nothing)," from More Piaf of Paris (LP, Capitol ST 10283). This is not a great recording, but it's a great song whose emotional effect depends almost entirely on forward-stepping momentum and drive. And, as I said at the beginning, the Sphinx "steps" with authority. The Sphinx driving the DeVore O/93s let me access the full texture and drama of Piaf's vocal art.


After stopping in the UK and booking passage on a steamship back to America, I installed KEF's LS50s ($1499.99/pair) in the system, and inserted John Fahey's Death Chants, Breakdowns and Military Waltzes (CD, Takoma TAKCD-8908-2) into the Puresound CD player. Instantly, I realized with certainty what earlier I'd only suspected: that the best of the Rogue Sphinx's many good features is its line stage. Everything I played was enjoyably detailed, transparent, and spacious. The Sphinx-LS50 combination took me by surprise by doing such things as room acoustic, image focus, guitar picking, bass plucking, and fiddle scratching better than I'd ever dreamed possible—even at double these prices. Now I was wondering: Could it be me? What if I'm incompetent, deaf, and gullible? What if the Rogue Sphinx is not nearly as good as I keep thinking it is?

Whenever a new component surprises or mystifies me, I reach for a recording I've played a thousand times through a hundred systems. Worried, I played a track by my favorite smart hipster women on synths: "Take Me as I Am," from Au Revoir Simone's Still Night, Still Light (CD, Our Secret OSRCO3). My anxiety ramped up. I had never experienced this volume or depth of bass. (I moved the LS50s three times to be certain that this enhanced bass wasn't a setup anomaly. It wasn't.) All types of new details appeared. With every track, I experienced big, vibrating air and microtextured reverb. I enjoyed it, but I was still worried.

Paris de la nuit
Seeking comfort and surety again in the City of Light, I looked up my childhood-fantasy femme and quickly remembered that I had not yet fully developed until I'd heard Brigitte Bardot sing Serge Gainsbourg's "Je Me Donne a Qui Me Plait," from her and God . . . created B.B. (CD, Hitland SML 015). Now I began wondering, What is it with these nouvelle chansons? I would think that playing them successfully would be all colorito and smoky atmosphere, but in practice, what these French singers needed was full-tilt momentum. No problem. What the Sphinx was best at was delivering forward musical movement. It also did weight and body. B.B.'s voice had a most tempting feminine presence.

I was lying on my couch, hanging with the avant-garde ca 1890, drinking absinthe at Le Chat Noir and listening to Erik Satie's ballet Mercure, with the Orchestra of Paris conducted by Pierre Dervaux (LP, EMI La Voix de Son Maåtre C 069-11677). It totally got hold of my mind. I was intoxicated. The Rogue's phono stage seemed lively, but a bit dense and opaque.

I exchanged the Ortofon 2M Red phono cartridge ($99) for the 2M Black ($719), which caused the Sphinx's phono stage to relax and open up. The ease and flow, and quirky mystery, of the Satie recording were now more accessible, and the Rogue felt more airy, liquid, and transparent. The soundstage expanded some.

Mercure features three sopranos and a mezzo-soprano, and this final system that I'd assembled—VPI Traveler turntable and tonearm, Ortofon 2M Black, Rogue Sphinx, KEF LS50s—reproduced their voices smoothly and elegantly. The sound was sweet. The contrasts between dark, solemn moments and bouncy, light-filled, free-dance passages were exciting to behold. High frequencies never drew attention to themselves.

How should I miss her?
For me, the best way to recognize what an audio component has brought to the party is to send it home and install another. While reinstating my beloved Creek 4330 ($495 in 2002), I noticed how solidly (and prudently) both were constructed. I also noted how neither company had invested in deluxe RCA jacks or speaker-binding posts.


When I played and God . . . created B.B. through the Creek, softer than the Sphinx was the first phrase that sprang to mind. Next came a little more distant. The beginnings and ends of notes became less distinct. Dynamic contrasts were reduced. But wait! Mlle. Bardot was suddenly more perfumed and sensuous, in her incomparable French way. I could see her standing on the beach at Cannes. Her smile made me smile.

Same with Daft Punk—the Creek amped up the color and atmosphere but reduced the scale and force of the bass. The 4330 made singers, flutes, and strings sound more plush but less corporeal. With the Creek, the dream factor was noticeably increased, the forward momentum and boogie factors clearly diminished. Hmm.

Integrated amplifiers are not like race cars. They are more like classic performance sedans: Engineered to be used and enjoyed over long stretches of time, the best such sedans showcase simplicity, traditional design, and durable high performance. Typically, they forgo some luxury options and put the savings into the engine, drivetrain, and suspension.

That's how I would describe the Rogue Audio Sphinx. I haven't spent time with the similarly priced integrateds from Arcam, NAD, Parasound, or Peachtree, but anyone studying the "Integrated Amplifiers" section of Stereophile's "Recommended Components" will notice that today's moderately priced integrateds offer an unprecedented number of alluring and competitive feature sets. I can imagine a young audiophile poring over this section, first comparing features and prices, and only at the end speculating about sound quality. Keeping that in mind, I suggest that the Rogue Sphinx's best features are the ones it lacks.

I went into this review with a clear prejudice against high-power class-D operation. I thought it would sound hard and generalized. I didn't think the Sphinx would effectively drive my 10-ohm DeVore Fidelity O/93s or my 15-ohm LS3/5As. I assumed that its phono stage would be nothing special. I was certain it would spoil my nuits à Paris.

I was wrong on all counts. The Sphinx played a wide range of high-quality loudspeakers with cunning authority. Its tubed line stage had a sound that was highly detailed, dynamic, and surprisingly transparent. Driven by a high-quality, high-output cartridge, the Rogue's passive RIAA phono stage was more than just okay or even respectable—it did high-speed boogie, air, and low-level subtlety.

In my full month of listening to the Rogue, I discovered the wisdom of its design. The Sphinx is all analog, which means that, five or even 20 years from now, everything the buyer paid for will still have value. If you upgrade your loudspeakers, that 100W amp should drive them without issue. If you get deep into vinyl, you can add a moving-coil step-up transformer—or even an outboard, super-quality phono stage into the Sphinx's line inputs.

Digital is evolving and improving so quickly that if you listen mostly to high-resolution digital, you might not want your integrated to include its own DAC. With the Rogue, you can add the modest DAC du jour and surf all the latest computer audio waves. Unlike the Sphinx's phono stage, whatever DAC these other integrateds come with will surely be outclassed and upstaged by something better—and sooner rather than later.

As I type this conclusion, I'm listening to the Ensemble Musica Nova playing the motets of Guillaume de Machaut (CD, Zig Zag-Territories ZZT 021002), with the Sphinx integrated driving the KEF LS50s via my most modest Oppo CD player ($170). I am experiencing genuine musical happiness. I don't need a million-dollar hi-fi. I just need a simple, no-nonsense integrated amp and some modest two-way speakers. Then, maybe, I can forget about audio, and be happy playing music for a long time.

Rogue Audio Inc.
PO Box 1076
Brodheadsville, PA 18322
(570) 992-9901

xsipower's picture

It’s nice to see that another manufacturer using Hypex’s OEM class-D amplifier modules perform so well. The last one Stereophile tested was the MBL Corona C15 monoblock power amplifier and it also performed very nicely (

Visually the 415 kHz ripple on the output appears incongruent to high quality audio, but apparently it doesn’t seem to impact the listening experience Mr. Reichert’s and Mr. Atkinson had. Makes you wonder if having a linear amplifier with radio frequency bandwidths (200khz and above) is really necessary or just a marketing ploy. The best tweeter rolls off sharply above 40 Khz and there is the question whether any audio information in any source goes beyond a few tens of kilohertz.

Hypex is demonstrating that Class-D has made it's place in the audiophile world when implemented properly.

Thank you for the review Stereophile.

BradleyP's picture

I'd love to hear a Sphynx! Class D has come of age. When I read reviews like these and see what kind of sound quality can be had for such do-able sums, I am convinced that these are the good old days of audio. A swell integrated that doubles power into four ohms--who ever heard of such at this price? As technology makes quality audio less and less expensive, it's possible in the future that an "audiophile" by today's standards will be anyone who owns a stereo. I just bought a $260 pair of new JBL studio monitors sporting four on-board class D amps for my desk, and they are almost a religious experience. (The good kind.)

BradleyP's picture

Oh, and thank you for the listening tip. The Guillaume De Machaut Motets are a real treat. Right up my alley. With the advent of Spotify, I devour every issue of Stereophile--I'm a paid subscriber--looking for music tips in the equipment reviews and always finding some keepers. Confession: on my desktop rig, which is no slouch, I am HARD pressed to tell the difference between 44.1/16 and a Spotify stream of the same material. I really ought to buy the stuff I like, but I like so much more than I can afford to buy. A trip to the online catalog (with audio samples!) which features the Zig Zag Territories and related labels is alike a trip to an art museum. Seriously do check it out:

remlab's picture

Nicely done. I'm really looking forward to your inteligent, thought provoking reviews. JA made a great move by bringing you in. It's just what the magazine needed.

commsysman's picture

The comment that the Sphinx is "all analog' is obviously incorrect, because any Class D output stage is a digital output stage.

Its output only becomes analog after the duty-cycle-modulated DIGITAL output of the switching stage is filtered back into an analog waveform by a filter.

deckeda's picture

That's a common misconception.

The modulated signal and filtering have constructs and methodology that superficially resemble digital signal sampling and filtering, and you could have an amplifier employ digital controls to the operation of the output devices but that's as far as it goes.

Transistors and MOSFETs are very much analog devices, and there's no ADC nor DAC at work here.

russ_777's picture

Agree, it's always been difficult to characterize because it has features that are both analog and digital in nature. At its core PWM is a non-linear analog modulation (similar to FM in that sense) as the width of the pulse within any period of the sawtooth carrier WF represents a continuously variable characteristic of the input waveform - that being the difference between the amplitude of the input waveform and the sawtooth carrier waveform where they intersect.

It "appears" to be a digital waveform because the output of the comparator and the output switching stage before the LPF has only two amplitude values - full on or full off. But the information from the input signal is carried in the width of the pulses, which is not discretized.

rimu's picture

Hey, I'm a bit surprised noone owning a unit comments anything. Probably thay are so much into listening, that they have no time to write comments anymore.

I've bought a used unit a few months ago after listening and comparing it with a few other candidates. I could definitely say that the Sphinx is a very strong contender in its price range. Nothing I heard of comparable price came even close. Musical Fidelity M6si felt sounding in about the same league as the Sphinx despite MF being twice more expensive. The point I'm trying to make is that Rogue sounds a class higher than it costs.

What may be not completely clear from the start is that despite being a hybrid, it's still a device with tubes inside. This means that the sound quality would be heavily dependent on the tubes used. The best choice to upgrade the tubes, in my opinion, would be vintage Telefunken ECC82. The amp truely sings with these tubes. The opposite is also true: using low grade tubes would kill all the beauty of its sound. Unfortunately I got my unit with already upgraded tubes and never had a chance to audition it with stock tubes.

Another thing one considering to choose the Sphinx should be aware of, is that this amp has various kinds of noise problems. First of all - the tubes matter in this regard - they give a pretty high noise floor in comparison to most solid state amps. Verious tubes have various problems with noise floor and microphonics. Another issue is specific for the Sphinx - it's humming. The power supply unit of the amp is not screened from the audio components under the hood. This is really disappointing. As a result you may hear humming with high volume and no input signal. It's not catastrophic at all and doesn't affect auditioning way too much. One should be prepared however that between the tracks you are likely to note the unit's noise.

All in all this amp sounds really sweet, with very high resolution throughout the spectrum. It a worthy choise and unless you are not willing to spend more money there are no other options with comparable fidelity. I had a great time with it and would definitely reccomend it as a great buy!

mrvco's picture

I replaced an MF M3i with the Sphinx v2 and couldn't be happier with it running a pair of Omega single-driver, high-efficiency speakers. The noise floor of the v2 is supposed to be lower than the v1 models. I did end up adding a Blue Circle Audio power conditioner since the Sphinx did let through some intermittent electrical noise that I hadn't heard in the past.

audioguy85's picture

Could the noise you mention be caused by the aftermarket tubes installed? also is this a v1 or v2? The review, at least for the v2 version made no mention of any appreciable noises, and the cv2 is supposedly more quiet, lower noise floor.

audioguy85's picture

I own the black version, the build quality looks to be all there. Very minimalist design which I like. Have not had the time to hook it up just yet, but will add a future comment as to how it sounds. For me it was a bit pricey as I normally go for the 500-700 range of integrated's, but I think I made a significant upgrade buying this. Time will tell. I appreciate that it Is a made in US product and I find the Class D combined with tubes to be interesting. I will be driving my wharfedale 225's with this amp, as I do feel they need a good push to sound their best. This Amp should do the trick, and if Stereophile's review is on the money, I think I will be very happy!

brad maestas's picture

I just received my Sphinx v2 in black yesterday and am having a ton of fun running it in. I am already very impressed, especially in its resolution throughout its gain range. I spend a good deal of time listening at lower levels late in the night and it still gives me a great sense of space and presence even at low levels. Granted, my previous amplifier was most certainly nothing special, a Harman/Kardon HK 3480, so it should be no surprise that it's quite a big step up however I've been able to audition and borrow quite a few nice separates and integrated amps over the last decade and the Sphinx is really quite something for the price. Right now it's powering Mission 703s that I'm soon upgrading to Wilson Benesch Square Twos.