Rogue Audio Sphinx integrated amplifier Associated Equipment

Sidebar 2: Associated Equipment

Analog Sources: VPI Traveler turntable & tonearm, Thorens TD-124 turntable; SME 3009 II tonearm; Denon DL-103, Ortofon 2M Red & 2M Black cartridges.
Digital Sources: Puresound A-8000 CD player, Line Magnetic LM 502 CA DAC, Oppo DV-980H SACD/CD player, HiFiMan HM-101USB soundcard.
Preamplification: April Sound (MM), Fi Yph, Sentec EQ11 phono stages; Intact Audio (MC) step-up.
Integrated Amplifiers: Creek 4330, 47 Labs Gaincard, Grommes 24PG, Line Magnetic LM518 IA.
Headphone Amplifier: Schiit Asgard.
Loudspeakers: DeVore Fidelity Orangutan O/93, KEF LS50, Konus Essence, Totem Model One Signature.
Cables: Interconnect: Auditorium 23, Kimber Silver Streak. Speaker: Audio Note AN-SPX, Auditorium 23 A23, Kimber Monocle XK & 8TS.
Accessories: Sound Anchor stands.—Herb Reichert

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.