Integrated Amp Reviews

Rogue Audio Pharaoh II integrated amplifier Page 2

Monday morning, I put on an RTI promo-copy test pressing of Promises, a composition by Sam Shepherd (known as Floating Points), performed by Shepherd on keyboards, Pharoah Sanders on saxophone, and the string section of the London Symphony Orchestra (LP, Luaka Bop LB97LP180). I was impressed by how warm, clear, supple, and flowing this recording sounded. Promises is a finely wrought sound collage: Sanders, Shepherd, and the LSO strings were each recorded in a different city and mixed later by Shepherd. The sound was elegant and pristine, with exquisite fine detailing set against silent backgrounds. I do not remember this recording ever sounding this compelling.

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When I played the regular-issue version of Promises, I noticed it was not as clean and silent as the test pressing. My consumer copy showed a faint amount of haze embedded in the sound. I attributed the haze to stamper wear. (This was a popular recording: Luaka Bop sold 14,000 copies in the first three hours after release.) Still, I was much impressed by how the Pharaoh II's phono stage and Goldring's $899 high-output Eroica HX moving coil cartridge made easy work of showing me this subtle difference.

I had to compare those black discs to the streaming version. Via Qobuz (24/44.1), Promises sounded smoother but lower in contrast; the reduction in contrast made instrumental color and sonic textures less distinct, while spatial effects, momentum, and pacing were enhanced. Listening through a Roon Nucleus+ server and the dCS Bartók DAC, my initial sense of the Pharaoh II's line-input transparency was quite positive. It was noticeably better than the Sphinx V3 it replaced in my system.

Auditioning the phono stage
My first step when assessing the phono stage on an integrated amplifier is to install a common moving magnet cartridge I know well and to play a simple, natural-sounding recording I've loved forever. With that as my plan, I installed Ortofon's $695 2M Black cartridge on Music Hall's $1649 Stealth direct-drive turntable and set it to a Lofgren-A alignment.

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The first disc I played was John Dowland's The First Book of Ayres (LP, Period Records SPL 727) with Safford Cape conducting The Pro Musica Antiqua. According to Cape, the airs on this disc are performed "in accordance with Dowland's indications and suggestions, in diverse settings, by a vocal ensemble, a broken consort of instruments, solo voices, and the Lute."

The intimate vocals showcased on these 22 short, freestyle madrigals embody my highest ideals for art and musical form. They are simple, humble, direct, danceable, and poetic—the opposite of pretentious or cerebral. The only things these songs require from a hi-fi phono stage is that it be pure of tone, clear as water, and light on its feet. With the 2M Black, the Pharaoh II did all these things extremely well—so well that I forgot about phono preamplifiers and just listened to the music. The Pharaoh phono stage let all the 2M Black's detail and John Dowland's joy come through cleanly, in an energetic and engaging manner.

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Another simple recording I've loved forever is Television's debut album, Marquee Moon. I saw them live at CBGB and played their album daily from spring till after Christmas 1977. I had it on LP (Electra 7E-1098) and a homemade cassette I played at work with a Walkman Pro and Koss Porta Pro headphones. These days, I'm playing the title song from a 45rpm, 12" single that was pressed in France. On this Special Limited Edition disc (Electra K 12252), guitars and drums are mixed forward of the bass and vocals. Even more than on the original pressing, the quick, sharp sounds of Richard Lloyd's and Tom Verlaine's guitars dominated my experience, appearing direct, strong, and right-there-in-the-room present. With the Stealth/2M Black feeding the Pharaoh and the Pharaoh powering GoldenEar's difficult-to-drive BRX speakers, the phono stage put forth its clean and clear best while Rogue's NCore amplifier modules jacked up the feeling of power coming from the GoldenEar speakers. The Pharaoh didn't notice the BRX's power-hungry stubbornness.

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Forgive me if I am overworking the Pharaoh's phono stage. I can't help myself. And I just hit major paydirt: As I type these words, I am listening to "33 Variations on a Waltz by Diabelli" (Op.120) from volume 5 of Artur Schnabel's Beethoven Piano Music (EMI 3LP, HLM 7338), and it is sounding super solid, with just the right tone. I am using Grado Labs' $400 low-output Platinum3 moving iron cartridge—see this month's Gramophone Dreams—which is placing the physicality of each keystroke, the nuanced energy and psychic range of Schnabel's pianism, right in front of me. The harmonic completeness of the Platinum3's sound is such that Schnabel's playing upstaged my critical brain and showed me glimpses of Beethoven's creative mind.

This could not have happened with just any phono stage. The Grado, a low-output (1.0mV) moving iron cartridge, requires moving coil–level gain (60dB) and a moving magnet–type load (47k ohms; footnote 1). My tubed Sunvalley and Tavish Design phono stages cannot accommodate those unusual requirements, but the Pharaoh II's phono input could and did. I can't imagine Pharaoh II users wishing for a better phono stage.

The Pharaoh II drives the Maggies
Each time I snug down the speaker-cable banana-plug set screws on the Magnepan .7 panel speakers, I picture the vast, illusionary spaces that are only moments away. I truly love this speaker. Every Rogue amplifier review must include some bathing in the deep-space lucidity of these (slightly) current-hungry, 54" tall, quasi-ribbon dipoles.

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I began my Rogue-Maggie listening with the music of young Irish guitarist Sean Shibe. His avant-garde compositions seemed perfectly tailored to the spatial-construction talents of the .7. The mind-grabbing tracks on his Pentatone album Lost & Found (24/48 Pentatone/Qobuz) include compositions by Shiva Feshareki, Julius Eastman, and my most beloved 12th century anchorite and current darling of the avant-garde, Hildegard von Bingen.

On the first Hildegard composition, "O viridissima virga," the sounds from Shibe's guitar hit my room like the Gong of Doom: strong, bell-clear, uber resonant, and sounding ever so much like a pipe organ. The End of Days felt near. With the Maggies driven by the Pharaoh II, the tactility factor—what Art Dudley called "touch"—was more noticeable than it had been on my Falcons or the GoldenEar BRXs. The Rogue-Maggie sound was room-expanding, deep, shimmery, and clear in a way that reminded me of Pass Labs' super-transparent XA25 amplifier. On this track, on these speakers, Rogue's Pharaoh II filled in those class-D voids with something like class-A radiance. Data density felt high. The extraordinary scale of presentation of the Pharaoh II and Magnepan .7 reminded me of the Maggies powered by LKV's Veros PWR+ class-D amplifier, which I reviewed in September 2020. Both amps played the Maggies with class-A tone and texture.

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Country blues was born from field hollers floating over solid, syncopated, jig-like dance rhythms, and no blues artist exemplifies this description better than Huddie Ledbetter (aka Lead Belly, 1885(?)–1949). Lead Belly was a musicianer: singer, songwriter, and master of phonetics on the 12-string guitar. His collected recordings describe a full century of African-American experience. Huddie died on December 6, 1949, but before that, on June 15 that same year, he performed live at the University of Texas. My white-label promo copy of this recording, Leadbelly Recorded in Concert, University of Texas, Austin, June 15, 1949 (LP, Playboy Records PB 119), is among my most cherished possessions. Its simple, minimally processed sound never fails to reveal the true character of the system that's playing it. It showed the Pharaoh II's worth by how densely, intensely, and intimately it pushed Huddie through the Magnepan panels.

This phono amp and speaker combination played "Goodnight, Irene" unforgettably, as though they were made for each other. The direct, sincere manner of this combination reminded me of what I experience while listening with planar-magnetic headphones.

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Huddie through headphones
I'll spare you my usual HiFiMan Susvara–vs–integrated amp torture stories and simply report on two headphone models the Pharaoh drove extraordinarily well. (Suffice it to say, the Pharaoh's 1.5W headphone output did not satiate the power-hungry Susvara.)

The headphone the Pharaoh liked best was Meze Audio's new $4000 Elite—an open-back, planar-magnetic design. Powered by the Pharaoh, the 32 ohm, 101dB/mW Elite delivered music with relaxed, pristine clarity. The Rogue–Elite pairing played Ledbetter live in Austin with an air of well-structured authority that said, "Who cares if the headphones cost as much as the amp? The sound is dang near perfect."

The headphone the Pharaoh II liked almost as much was Sony's $1799 MDR-Z1R, the closed-back I have used more than any other headphone since I reviewed it in GD16. Because they are so comfortable, durable, natural-sounding, and easy to drive, the 64 ohm, 100dB/mW Z1Rs have never stopped being my paint-splattered daily headset. They employ fast, 70mm magnesium domes that never hint that they're made of metal. Powered by the Pharaoh II, those domes sounded like they were made of paper: not too soft or hard, space and detail displayed with an appealing tube-like sheen. A recommendable match.

A class-A soundalike
When I wrote the intro to this story, I already knew the outro: Rogue Audio's Pharaoh II integrated amplifier delivered enough quiet, clear, clean, effortless class-D power to drive the hard-to-drive (under 4 ohm EPDR) GoldenEar BRX and the current-sucking Magnepan .7 panel speakers. It also excavated some of that extra data I said my DIY friend should ask for: teeny-tiny class-A atmospherics and barely discernible nano-energies to make me forget it was class-D. But it did more: It showed me the best phono stage I've ever found in an integrated amp. No question, I got more than what I asked for.

Footnote 1: I've seen it suggested that some of Grado's moving iron cartridges, which have an internal impedance from 75 ohms up to 660 ohms, like a 10k ohm load, but that setting is rarely available except on phono stages that allow custom loading.—Jim Austin
COMPANY INFO
Rogue Audio Inc.
PO Box 1076
Brodheadsville, PA 18322
info@rogueaudio.com
(570) 992-9901
rogueaudio.com
ARTICLE CONTENTS

COMMENTS
Glotz's picture
Submitted by Glotz on December 10, 2022 - 11:09am

I really appreciate your personal insights on this as well as SET Tube-based amplification.

But what about single-ended transistor-based amps?

I've had my eye on the Audio By Van Alstine DVA-225 monos (SET), and I'd really like to put my ear on them sometime. Given their direct, custom order business model, it takes a bit more courage to audition.

I'm also searching out the Rogue hybrid power amps to feel them out as well.

I'd really like to see the market put out a GaN-based power amplifier for under $5k as well. I'm sure one day that will happen, given their burgeoning presence in the market now.

Very nice column as usual; I always feel like we know your brain and soul a bit more with every month's writing.

Happy Holidays to Herb and the rest of the Stereophile staff!

Herb Reichert's picture
Submitted by Herb Reichert on December 12, 2022 - 9:13am

My solid-state reference amplifier for use with the Falcon speakers is the Nelson Pass-designed First Watt F8; which is single-ended, and uses a touch of 'tidy-up' feedback.

To my way of looking, the F8, and its First Watt sibling, the J2 (also single-ended), and the SIT-3 are among the most innovative amp designs of this era.

In audio we must always champion innovation and engineering diversity. If we don't, the listening party is over.

hr

Jack L's picture
Submitted by Jack L on December 12, 2022 - 12:19pm

Hi

Indeed.

F8 employs current feedback intead of voltage feedback used in J2.

As Nelson Pass said: "I enjoy amplifiers with a little personality",
the power output coupling capacitors he used are "2 big electrolytic & one PP capacitor with a roll-off of 1Hz."

All capacitors get their own "personality" sound qualtiy. The last type of caps I would ever use for music signal coupling is electrolytic due to its complex dissipation factor & ESR etc etc due to its dielectric used. Not sooo good sounding at all.

For F8 $4,000 selling price, Nelson could have used better sounding coupling capacitors than electrolyitic.

FYI, I don't even electrolytic capacitors for power supply ripple filter caps for its sonic issue. I've used motor-run OIL capacitors instead !

Listening is believing

Jack L

georgehifi's picture
Submitted by georgehifi on December 10, 2022 - 12:56pm

JA:"The Pharaoh II's reproduction of a 10kHz squarewave (fig.2) showed only the slightest hint of overshoot, with no ringing."

Is this the reason there is no hint of overshoot, because you can't see it when it's measured at low level + - 1v output, with the AUX-0025 bench testing filter installed on the amps output?

Cheers George

John Atkinson's picture
Submitted by John Atkinson on December 11, 2022 - 5:21am
georgehifi wrote:
JA:"The Pharaoh II's reproduction of a 10kHz squarewave (fig.2) showed only the slightest hint of overshoot, with no ringing."

Is this the reason there is no hint of overshoot, because you can't see it when it's measured at low level + - 1v output, with the AUX-0025 bench testing filter installed on the amps output?

No. You can see from the frequency response curves in fig.1, which were taken without the auxiliary filter, that the Rogue's output rolls off smoothly above the audioband into higher impedances. There is is only a hint of an ultrasonic peak into 2 ohms (green trace).

John Atkinson
Technical Editor, Stereophile

georgehifi's picture
Submitted by georgehifi on December 11, 2022 - 2:57pm

that's odd

John Atkinson's picture
Submitted by John Atkinson on December 12, 2022 - 10:13am
georgehifi wrote:
Sorry JA, I beg to differ, maybe you forgot the AUX-0025 was used to do the square wave shots.

I didn't forget. But without the AP auxiliary filter the squarewave response is obscured by the ultrasonic noise that I mentioned in the measurements. That is why I use the filter for the published 10kHz squarewave. The filter removes the ultrasonic noise without significantly affecting the shape of the waveform.

I don't use the filter for the frequency response measurement as I want to see the actual behavior of the class-D amplifier's own low-pass filter. The Rogue amplifier's filter is well-behaved, with the shape of the ultrasonic rolloff correlating with the squarewave response.

georgehifi wrote:
As the response curves and square waves shots look the same and level for all other Hypex NC500 equipped amps you've measured but stated you used the AP AUX-0025 on their outputs still at the same + - 1v. (why measure the Rogue' square wave output at only 1vpp if the AUX-0025 wasn't used?)

The frequency response and squarewaves I publish in amplifier reviews all show the small-signal behavior, ie, the amplifier is operating at an output level where it is linear. The level of the squarewave doesn't affect its shape.

Note, BTW, that the scaling on fig.2 is arbitrary, as the digital 'scope is being fed from the Audio Precision SYS2722's Monitor output. It is not the actual level I use for this measurement, which was actually 2W into 8 ohms.

John Atkinson
Technical Editor, Stereophile

windansea's picture
Submitted by windansea on December 10, 2022 - 2:35pm

I enjoyed Herb's ruminations on Class A and D (which he's discussed in other reviews). I have both types of amps, as well as a 12AU7 based preamp, so this review really spoke to me. I imagine that a NOS tube would sound even nicer in the Rogue than the JJ tubes. As long as you're spending a few grand, spring for some Siemens or Telefunken or bugle boys.

Now that the weather has gotten a bit chilly where I live, I brought my "winter amp" (Class A) out to the living room where the wasted heat is welcome for 3 months.

A technical question: does it really matter for an ncore unit if it's a switching power supply or a toroidal? I've heard that switchers might have more EMI, but a regular transformer has ripple that needs to be tamed by caps and chokes. I think we can stipulate that linear is simpler and thus more reliable.

Jack L's picture
Submitted by Jack L on December 12, 2022 - 11:16am

Hi

Yes, NOS or old Telefunken or even made-in-UK new Mullards would sound better than JJ tubes. I used both for my design/built phono-preamp !

BUT from pure technical viewpoint of designing Mu-Follower which is used in the Rogue integrated amp, I would NOT used ECC82/12AU7 which got too much Mu for the lower half of the twin triode which would work not sooo stable in the event of the operating plate voltage drop due to power surge etc.

The much better twin-triode I would recommend is ECC81/12AT7 which get good gm but not too high Mu & still works stably in the event of plate voltage drop for whatever HVPS issues.

Yes, Mu-Follower is efficient & high gain & gets super lower harmonic distortion provided it is NEVER overdriven to clipping !!!! Once overdriven, it produdces tons of even & odd harmonic BLOCKING distortions considering the hi-gain op-amps are used for its RIAA phonostage !!!!!!!

I don't mind discuss the design issues of this Rogue amp with its whoever designers. For a bit more cost money using discrete devices, best using triodes, it would sound even much better, IMO.

Listening is believing

Jack L

MatthewT's picture
Submitted by MatthewT on December 12, 2022 - 1:52pm

I'm interested in this amp, but am not willing to spend any money on it until you fix it for them.

"I don't mind discuss the design issues of this Rogue amp with its whoever designers."

Jack L's picture
Submitted by Jack L on December 12, 2022 - 1:57pm

.

MatthewT's picture
Submitted by MatthewT on December 12, 2022 - 1:58pm

Pal.

georgehifi's picture
Submitted by georgehifi on December 10, 2022 - 3:04pm

Yes it does to my ear, as I have the NC500's in mono-block form (used with no buffers) because my discrete R2R MSB dac (with volume control)and can put out enough bal volts direct into the NC500's for the loudest that I would ever listen to on my 89db speakers

And with Hypex's own SMP (switching supply) they had, while good, it could not equal the Linear Toroidal power supplies I substituted for them. Much less sterility and more body to the sound, the only place the SMP's equaled the linear supplies was in the bass slam, but again not for body detail. EG: double bass being bowed, both as taught as each other, but the gut of the bow comes through far better on the Linear Supply.
I'm all behind Rogue etc for using linear supplies for their Class-D Intergrated and power-amps, while much more expensive and using far more real estate they sound far better, if designed correctly.

Cheers George

windansea's picture
Submitted by windansea on December 10, 2022 - 10:45pm

I've got one amp with NC1200 modules and maybe I'll try a linear power supply. My class A amp has a giant toroid and big caps-- wonder if I could divert that as an experiment. Time to call my electrical engineer buddy...

Jack L's picture
Submitted by Jack L on December 12, 2022 - 10:36am

Hi

BINGO ! NEVER ever use any SMPS for any audio amps, period. It is a last stage of RFI/EMI cancer for any audio amps !

Any SMPS emits RF noises airborne & thru hardwiring into any powerlines associated with it. Any other audios plugged in the same & even remotedly connected powerlines in the same premises get in as free bonus.

Don't need any costly powerlines noise testers, like the wideband powerline noise analyzer I use all the time to test the RF noise there or not. Any AM radio will get extremely noisy when placed near any those SMPS wallwarts !

That said, I still use a SMPS wallwart to recharge the bias batteries for all the tubes inside my design/built SET power amp - convienient & cheap ! But surely the wallwart, plugged in a wall outlet totally detached from my audio rig dedicated powerlines.

For RFI/EMI noises, never take for granted !!!!!!

Jack L

PeterG's picture
Submitted by PeterG on December 11, 2022 - 6:56am

Finally! A rave review of a Class D that does not ignore the elephant in the room--Class A. I love my tubes too much to switch, but it's great to see the new tech emerge. Thanks

georgehifi's picture
Submitted by georgehifi on December 13, 2022 - 1:03am

Hmmm! Please don't delete, comments are for debating + & -'s also.

Sorry JA,I have these NC500 modules here, and they vhf ring (just like this at only 1khz!! https://ibb.co/R2NPzHQ ) with (switching noise) with even 1khz let alone 10khz square wave on the scope without using a low power external AP AUX-9925 type filter or similar, as will/do any other amp that uses the NC500 modules.

Cheers George

georgehifi's picture
Submitted by georgehifi on December 13, 2022 - 11:39am

Submitted by Jack L: "Any SMPS emits RF noises airborne & thru hardwiring into any powerlines associated with it."

So true, all they achieve is more profit, as they are cheaper and take up less real estate than good Linear Supplies.

Cheap Test:
With an old portable transistor AM radio (that doesn't auto mute off channel)
Tune it down low 600khz-700khz off channel with the volume up and go near any smps with it, and hear what's bombarding your audio signal.

Cheers George

Jack L's picture
Submitted by Jack L on December 13, 2022 - 1:02pm

Hi

My small 33-years-young Panasonic pocket radio always tuned to 680KHz (our local gas price forcast channel) gets noisy like hell whenever placed near any plugged-in SMPS wallwart.

You can imagine same RF noises airborne into yr HIFi system - no execption !!!!

Any cheapie yet very effective way to safeguard yr HIFI from RF noise airborne invasion ???

Of course, there is. I already DIY-installed such anti-RFI devices to
ALL my audio components even including all my pure silver interconnects, power cords, loudspeaker cables etc etc etc. since day one.

Never befriend with RF/powerline nosies !!!!!

Jack L

windansea's picture
Submitted by windansea on December 13, 2022 - 4:41pm

Benchmark Audio offers the contrary view:
google for full version:
AUDIO MYTH - "SWITCHING POWER SUPPLIES ARE NOISY"

THIS MYTH GOES SOMETHING LIKE THIS:
"Switching supplies are noisy."

"Linear power supplies are best for audio."

We disagree!

About 5 years ago, Benchmark stopped putting linear power supplies into our new products, and we replaced them with switching power supplies. We did this because linear supplies are too noisy. Yes, you read that correctly, linear supplies are noisy! A well-designed switching power supply can be much quieter than a linear supply.

LINEAR POWER SUPPLIES CAUSE HUM
The noise problem is due to the fact that linear power supplies have large transformers and other magnetic components that operate at the AC line frequency (50 Hz to 60 Hz). These line frequencies are audible, and we are all too familiar with the hum and buzz that audio products can produce. It is no secret that this noise is caused by the power supply, but few people understand why it can be so hard to eliminate. Most people think that hum is caused by conducted interference (AC ripple on the power supply rails), but this is rarely the case. Most AC hum is caused by magnetic interference, and this can be very hard to eliminate.

HUM IS USUALLY CAUSED BY MAGNETIC INTERFERENCE
Transformers are magnetic devices. Power is magnetically transmitted between a transformer's input and output windings. In a linear supply, power is transmitted from the AC line side of a transformer to the low-voltage secondary side using an AC line-frequency magnetic field. Unfortunately, transformers are never perfect, and some energy always escapes through stray magnetic fields. These stray fields can interfere with virtually every electrical conductor in an audio product. Magnetic shielding is expensive and it has limited effectiveness when sensitive circuits are located in close proximity to a strong field.

POWER AMPLIFIERS ARE THE WORST OFFENDERS
The power supplies in high power devices, such as audio power amplifiers, can emit very strong magnetic fields. These strong fields tend to limit the noise performance (SNR) of power amplifiers. These magnetic fields can also cause interference with audio products that happen to be too near the amplifier. Audio cables that enter, exit, or pass near the amplifier may also pick up unwanted hum and buzz. For this reason, it is usually very important to keep the power amplifier well separated from cables and other components in the audio system.

BREAKING ALL THE RULES!
Benchmark's new AHB2 power amplifier breaks the rules. It can even be located adjacent to sensitive audio components without causing interference! The AHB2 is a high-power device, but it emits almost no magnetic interference. What makes it different?

The secret inside the AHB2 is the switching power supply. This power supply has several high-power transformers, but they are very small, and their stray magnetic fields are correspondingly small. The reason for this is that the magnetics operate at 200 kHz to 500 kHz. For a given power rating, transformer size decreases as the operating frequency increases. High-frequency transformers have smaller cores and fewer turns of wire. As the physical size decreases, there is a corresponding reduction in stray magnetic field strength.

SIZE MATTERS
When transformers are physically small, there are more options for magnetic shielding. For example, the small transformers used in the AHB2 are completely encased in a ferrite material which helps to contain stray magnetics. These techniques are so effective that the AHB2 achieves a SNR of 130 to 135 dB. No power amplifier is quieter than the AHB2. Even more amazing is the fact that the switching power supply board is less than an inch above the amplifier board. This product proves that switching power supplies can be very quiet! The AHB2 could not achieve this level of performance with a linear supply unless the supply were housed in a completely separate box a couple of feet away.

OUT-OF-BAND NOISE
One major advantage of switching supplies is that the operating frequency is above the range of human hearing. If interference occurs, it will not cause audible interference. This interference can even be removed with a filter without infringing on the audio band. But, the power supply in the AHB2 is so quiet that we do not need to filter the audio output. The AHB2 delivers a 200 kHz bandwidth without evidence of any significant switching noise, to a measurement limit of 500 kHz.

LINEAR AMPLIFICATION WITH SWITCHING SUPPLIES
Please note that the AHB2 is not a class-D switching amplifier. The AHB2 is a linear class-AB amplifier. It is only the power supplies that operate in a switched mode. The power supplies simply provide steady and constant regulated DC voltages for the linear audio amplifier.

MatthewT's picture
Submitted by MatthewT on December 13, 2022 - 5:21pm

They didn't consult Jack.

Jack L's picture
Submitted by Jack L on December 13, 2022 - 5:56pm

.

MatthewT's picture
Submitted by MatthewT on December 13, 2022 - 6:03pm

To defend your argument. So far you know more than Rogue and Nelson Pass. Go for the trifecta and add Benchmark?

Jack L's picture
Submitted by Jack L on December 14, 2022 - 4:40pm

HI

Anybody knows the basic of Switched-Mode Power Supply (SMPS) will disagree what Benchmark reportely stated per your above post!

Instead of standard linear power supply rectifying the grid power (50/60Hz) to DC, SMPS generates the required power by switching a tuning coil at a very high frequency (from many hundred KHz to many mega Hz) & then rectified it to DC. Such HF switching produces a rippling voltage with high harmonics = electromagnetic interference EMI which is transmitted in the air & pass out via direct wiring, e.g. via its power cord.

There why when you open up any SMPS, you will always see a metal cover to cover up the switching electronics therein to shield off the airborne EMI, & a low-pass filter comprising coil(s), capacitor(s) to filter off the EMI from going out the SMPS with the rectified DC.

The problem is it is indeed a big deal to contain the EMI effectively inside the SMPS. In fact SMPS for commercial application are required to have their own very effective EMI suppression in order to be allowed to be usesd without affecting the existing electrical/electronic establishment.

Airborne EMI: a small battery-powered AM radio easliy detects airborne EMI from a working SMPS wallwart, like cellphone/tablet charger & the like. The radio get very noisy when placed nearby the wallwart !!

Powerline EMI: take an common example of any CD/DVD player which most most, if not all, come with built-in SMPS. Whenever the player is switched on, the built-in SMPS discharge EMI into the wallout/powerline which I detect without fail in my brandname wideband powerline & EMI noise digital analyzer.

Yes, SMPS is extremely power efficient up to 95%, stable output voltage & current (provided not overloaded!!) & compact in size relative to standard linear power supplies. BUT its EMI is hard to control!!

"Out-of-band" noises

EMI intermodulation products, 2nd, 3rd..orders of the switching frequency & its HARMONICS can go into the audio spectrum. Sensitve ears can find such intermoduations much more annoying than normal harmonic distortion due to the characteristic of our auditory system.

That's why. taking the example of a brandname powerline filters (made-in England), which I installed in the dedicated powerlines for my audio rig, are super wideband: 20KHz - 100MHz & way way beyond to GHz (out of the bandwidth chart) with max insertion loss of 52dB @ 32MhZ & 35dB @ 100MHz. This would cover EMI noises from any UPS & cellphones (1GHz - 6GHz+++).

Yes, standard linear power supplies do get 50/60Hz hum noise, which can be reduced to be ear inperceptible if done properly. But such noise is ear friendly vs EMI intermoduation products can sound from annoying to irritating.

YES, SMPS with really efficient (but costly) EMI suppression can measure superb but stil can NOT match the ear-friendly analogue noise produced by standard linear power supplies in music reproduction.

SMPS may win the noise-level battle but lose the war musically !!!!

Listening is believing

Jack L

windansea's picture
Submitted by windansea on December 15, 2022 - 1:14pm

Please explain further how the intermodulation distortion of extremely high frequencies can get back into the audible spectrum? You may have a point there but I don't get it. Aren't the harmonics happening at even higher inaudible frequencies? And therefore doesn't the low-pass filter cut these off from reaching the listener?

Also, Benchmark made a point about magnetic interference from linear supplies. Any reply to that? Personally I can't stand any hum. I had hum with a Jolia amp two decades ago, found it intolerable for hifi. My current systems (SET, tube pre, Pass class A, nCore class D) all have zero hum and that's a top priority for me.

Jack L's picture
Submitted by Jack L on December 18, 2022 - 4:50pm

...... can get back into the audible spectrum?" qtd windansea.

Hi

Michael Fremer commented on the same question you just asked in his review of Yunyata Denali power conditioners:
"But Shunyata doesn't explain how noise at a frequency of 1MHz can affect the audioband (20Hz–20kHz)."

So let me do the explanation:-

The intermodulation products are spurious frequency components generated when two or more signals pass through a non-linear device. The intermodulation products can be of different orders, such as second-order or third-order, depending on the non-linearity, number, and frequency of signals present in the system.

For SMPS, the high orders of harmonics generated with the switching frequency spread over pretty wideband frequency spectrum down to audio range.

The low-pass filteres inside a SMPS, if done properly, should remove any EMI noise from the DC coming out from the SMPS. As I already said above,
SMPS for commercial use MUST equipped with EFFECIVE EMI suppressors in order to be allowed to use in commercial establishsements.

For for audio amps & other digital gear, e.g. CD/DVD/DAC etc, the built-in EMI filters may not be effective enough to do the job right. That's why I can detect such EMI discharged from the SMPS into the powerlines with my EMI analyzer.

As I already said in my above post, the 50/60Hz hum noise & the magnetic flux leakage from the power transformers can be eliminated beyond ear perception if done properly. But such noise is analogue, friendly to our ears vs EMI noise annoys or even irritates our ears due to the chararteristics of our auditory system.

My design/build TUBE phono-preamp & SET power amp & my upgraded brandname tube phono-preamp & tube power amp got no audible hum at all.

Please read between the lines to differentiate sales pitch from electrical physics !!

Listening to analogue is believing

Jack L

tenorman's picture
Submitted by tenorman on December 20, 2022 - 12:41pm

Dear Jack ,
Overview. Grandiose Narcissistic personality disorder is a mental health condition in which people have an unreasonably high sense of their own importance. They tend to brag and be elitist .Those with grandiose narcissism are arrogant , aggressive, dominant and exaggerate their importance.

Jack L's picture
Submitted by Jack L on December 20, 2022 - 5:19pm

Hi

Don't need to throw me such mentality terminology! Sourgrapes !

KNOWLEDGE is the power of domination!

Lack of knolwedge will dwarf whoever into inferiority complex.

My question to YOU: do you own the audio knowedge needed to show your domination here ???????

How many post(s) of yours in audio technology, if any at all, ever got published in Stereophile journal??? Show us, please.

If you don't got any here at at all, please learn such audio technology knowedge before you stick your head out to be chopped literally.

You are more than welcome to show off your audio electronic knowledge provided you really got it !!!

I am all eyes !

Jack L

Jack L's picture
Submitted by Jack L on December 20, 2022 - 6:02pm

Hi

KNOWLEDG is the power of domination !

(Sorry, Mr. Editor, I am way out of audio here. Please bear with me. Thanks)

As an electrical engineer dealing in the electral power industries for decades in USA/Canada, audio electronics to me is a piece of cake !

Just show off to YOU my power of domination in electrical power engineering:-

Many many years back, a field engineer from a neigbour city power company called me up frantically for help in restoring electrical power to a regional blackout! He told me the VHV overhead transmission line was brown down by the snow storm. He needed miles of such particular overhead power like yesterday to reverse the blackout. The problem the power company engineer did not even know what cable was it exactly !

I requested a short piece of cut sample of the down powerline which arrived within one hour to my office.

On checking the over diameter & strand number of the cable, I made a phone call & within 2 days the miles of brandnew replacement powerline was thrown in by air & delivered to site !

Needless to say, I made excellent money for my employer for such emergency solution !

KNOWLEDGE is the power of domination !

Jack L

I

David Harper's picture
Submitted by David Harper on December 22, 2022 - 11:36am

You described Trump perfectly.

stungun's picture
Submitted by stungun on December 22, 2022 - 2:24pm

... particularly compared to the Sphinx v3. Wondering if that's because the Sphinx moved HR more in absolute terms, or if it is the combo of Sphinx sound and its value quotient that make it the more exciting product.

DrGregC's picture
Submitted by DrGregC on December 23, 2022 - 6:52am

The $64,000 question - How does the Pharaoh II sound compared to the original Pharaoh? In looking for the correct amp for my KEF LS-50's, I was surprised and blown-away when the dealer hooked-up the original Pharaoh. I always thought of it as a well-kept secret. Unlike his other products, Mark never tweaked or offered upgrades to the original since the introduction in 2015. Pretty good first effort. The model II is so different, that he doesn't offer an upgrade path. This review doesn't make me want to run out and buy the new version.

asherrick's picture
Submitted by asherrick on December 28, 2022 - 2:33pm

Greg,

The Pharaoh II is a substantial improvement over the original. Is it worth the upgrade cost from the original Pharaoh? That's a question only you can decide (and hopefully your dealer can help you by taking your amp on trade).

klangyog's picture
Submitted by klangyog on August 30, 2023 - 8:00pm

Thanks Herb for the as-always excellent review! I am a happy Sphinx V3 owner but I am having "impure thoughts" now about the Pharaoh II. BTW I share your enthusiasm for Television's "Marquee Moon" - a great, life-changing record that I have also loved since it came out. Nerd alert! Elektra Records is not spelled "Electra," but has a "k" in the name. Thanks for listening!

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