The Stellar M700 mono amplifiers are a massively powerful engine capable of effortlessly driving demanding loudspeaker loads to concert levels. Stellar’s best. A pair of these placed on any loudspeaker brings forth the lush, rich and soul-satisfying power of two completely independent power blocks with headroom to spare. One listen to a hugely loud and complex musical passage effortlessly rendered by the M700 pair and you’ll know you made the right choice.
Rated at 350 Watts into 8Ω and 700 Watts into 4Ω, the M700 combines the best of two worlds: ultra linear, high-current, Class D technology for the output stage; a discrete, Class A MOSFET based Analog Cell for the all-important input stage. The M700’s rich, warm, and engaging sonic character comes from the Analog Cell. Its powerful, authoritative control over the loudspeaker stems from its high current, ultra-low impedance Class D output stage.
Stellar’s design imperative was to produce a truly musical sounding power amplifier that proudly competed with any amplifier under $5,000. Its designer, PS Audio engineer Darren Myers, took the challenge and set to work on a new concept—a hybrid that would combine the best of today’s technology with time-honored techniques leveraging PS Audio’s forty plus years of experience.
The results are extraordinarily musical. Even from the earliest prototype we knew the Stellar power amplifier series was going to be something special. Stellar amplifiers never draw attention to themselves, a rare quality in amplifiers of any price. After hundreds of hours of tuning, voicing, and perfectionist tweaking, we were confident the ends justified the means.
Audition the Stellar M700 pair and you’ll appreciate Myers’ dedication to musical truth without compromise.
All amplifiers sound different. What determines sound quality are the components and topologies of the amp’s input voltage stage and output current stage. Each section should complement the other. Between them, the amp develops its sound.
Stellar’s design imperatives—affordable pricing, uncompromised sonics—were major challenges solved by the invention of a unique new circuit christened the Analog Cell™.
Stellar engineer Darren Myers had planned from the outset to take advantage of Class D’s high current, low distortion, ruler flat linearity for the output stage—knowing full well it is the input stage that determines sonic character. This critical interface between preamplifier and power amplifier is where Stellar’s magic would be unveiled; where Myers could lavish upon the music the sweet, tube-like quality of Class A biased MOSFETs. His challenge was to synergistically marry both input and output topologies, for which he invented Stellar’s Analog Cell.
The Analog Cell is the heart of the M700’s musicality, where richly overlayed layers of music’s inner details are preserved even in the most complex orchestral crescendos. The Analog Cell is a proprietary, fully differential, zero feedback, discrete, Class A MOSFET circuit, hand-tuned to capture the smallest micro dynamics without sacrificing the loudest macro dynamics music has to offer.
The Analogue Cell
The power amplifier is technology always present in stereo systems. Yet, despite the fact everyone uses them, few appreciate the power amp’s critical role in preserving music’s nuanced details, because most amplifiers fail to preserve them. Overtones from plucked instruments, subtle cues defining placement, depth, soundstage width, and transient decays are often lost in the power amplifier.
The M700 loses nothing. Stellar’s lead designer, engineer Darren Myers, was obsessed with its detail and voicing—lavishing great attention on even the tiniest nuances in the music. This helped Stellar capture the rich full-bodied essence of recorded music and presents it to your loudspeakers with authority and grace—with never a hint of glare or unnaturalness. The M700 is faithful to the music like few amplifiers are.
The Analog Cell makes all the difference
The connection between preamplifier and power amplifier is critical, for it is at this junction where most essential musical details are easily lost. Nothing in the design of a power amplifier is more important than its input stage when preserving music’s finest nuances. In the M700 a unique topology called the Analog Cell has been employed to preserve the rich details found in music.
The Analog Cell is a zero feedback, balanced, Class A, MOSFET input stage. The design closely mirrors the sonic characteristics of a vacuum tube and allows Myers the freedom to voice the amplifier as he sees fit. Long hours of listening and tuning sessions in Music Room One, shared by PS Audio founder Paul McGowan and Darren Myers, resulted in a sonic signature that honors the music and never draws attention to itself.
The listening experience with the M700 starts feet tapping and smiles breaking out. The M700 presents music without a hint of glare. Listeners are constantly surprised at the width and depth of the M700’s soundstage; its preservation of the smallest details in reverb, room acoustics, musical overtones; its commanding presence without intrusion; it’s delicate handling of subtle shadings; its authority as it grabs hold of the loudspeaker and breezes through even the most complex musical passages.
The Output stage
The hybrid approach used in Stellar’s power amplifiers takes advantage of the best traits technology has to offer. Its all important input stage relies upon the Analog Cell to provide a zero-loss interface between the preamplifier or DAC, as well as imprint the amp’s sonic character. It is then time to convert the perfected analog voltage into the all important high current output needed to drive loudspeakers.
A power amplifier connects a reservoir of energy to the loudspeaker through a type of valve (solid state or vacuum tube) controlled by the input stage. If the input stage has done a good job of preserving music’s subtle details, textures, timing and phase information, transferring it without loss to the loudspeaker can be accomplished in a few ways: the most efficient is Class D.
The history of Class D amplifiers stretches back to the 1950s, though those early designs—even those into the late 1990s—had much to be desired, sonically. Modern designs capable of high linearity and neutral sound quality weren’t available until the early 2000s, and into late 2015.
There is a lot of misinformation surrounding class D amplifiers. Perhaps the most common is they are digital, which is incorrect. A Class D amplification stage is an analog process, known as Pulse Width Modulation (PWM). Class D amplifiers do switch in on/off fashion, which is likely the reason they wrongly acquired the “digital” moniker.
The Stellar M700 has a massive power supply and ultra-linear high Wattage power amplification stage, based on a modern Class D ICE module, designed in Denmark.
All power amplification stages have strengths and weakness. Class D output stages are no different. Their strengths are many: near-perfect linearity, low distortion, high efficiency. Areas where they do not excel, are most notable in high-frequency extremes. Because Class D amplifiers require an output filter to remove their switching noise, they do not have frequency extremes into the many hundreds of thousands of Hertz. Depending on their design modern Class D amplifiers, like the type used in Stellar, extend high frequencies to about 50kHz. Human hearing limitations are 20kHz, though most listeners rarely have hearing exceeding half that.
The Stellar M700 provides excellent frequency extremes, low distortion, high efficiency, high damping factor, and a generous and powerful output of 700 Watts into the most common loudspeaker loads of 4Ω. Plenty of horsepower for even the most demanding loudspeakers.
Is 700 Watts too much for my loudspeakers?
No. One of the common audio myths is too much power for speakers. The truth is, underpowering a loudspeaker is potentially more damaging than over powering it. Square waves (clipping) causes more tweeter and driver damage to speakers than anything else. The massively powerful nature of the M700 works well with any loudspeaker, providing huge amounts of headroom and effortless sound quality for even the most demanding orchestral crescendos.
Work on the Stellar series began in 2015 with the goal of building a line of world-class, exceptional sounding, under $2,000 full-size chassis products at our Boulder facilities. What we hoped for was an affordable gateway into the world of PS Audio. We wanted to build a line of equipment we would be proud to place the PS Audio name upon, and customers would be equally proud displaying in their homes, at prices anyone can afford.
Our standards have always been high. In our forty plus years of business, we have never sacrificed quality, performance, or customer service when we launch a new product. If we can’t proudly take a new product home and enjoy its musical delights, then it’s never going to see the light of day as a PS musical instrument. Nothing is more important to us than honoring the music and those that use our products.
The first major challenge in Stellar’s creation was how to build a beautiful, full-sized chassis, and still have budget enough for the level of audio quality we had envisioned. Once solved with the tireless help of PS Engineering and a cartel of local vendors eager to keep business local, our next hurdle was the biggest of all—crafting musical circuits that matched our lofty vision of sonic bliss. Nearly two years in the works, our vision of a locally built gateway line of musically gorgeous audio products took shape. The Stellar line became reality and one we hope will enjoy a lifetime legacy in the PS Audio family.
The Sound Advocate
Once auditioned in your system you will be captivated by their alluringly natural, neutral, and just plain outstanding sound quality. The huge amount of power they are endowed with provides sound with breathtaking exhuberence when mated with almost any loudspeaker it is married to. These units are meticulously built and sound great right from the get-go. The M700 monoblocks are a standout product that deserves all the praise one can give to it.
All PS Audio components I’ve encountered (or owned) are incredibly well-built and the Stellar line is no exception. They have a weight, look and feel that exudes quality belying their sub-$5,000 USD total cost and puts me in mind of gear I’ve reviewed costing double this price point.
The PS Audio Stellar ‘three-fer’ proved itself to sound far more captivating, powerful, lyrical, musical and possess a humanity to its sonic signature in playback of all types of music than I previously thought a preamplifier and mono blocks priced under $5,000 USD would be capable of. They would, without fail, elicit both an emotional and physical reaction whenever I played music through them and their lack of digital pretense and healthy dose of analog spirit was a listening experience which I embraced.
I was really able to hear the amplifiers’ real attributes: astonishing and accurate bass, with sparkling highs that had an almost tube-like sound. How did they accomplish this in such a small footprint for such an amazing price?
In the end I believe this is the top of the line in its price range. Nothing comes close—the sheer amount of power and sound quality that comes from these little chassis is nothing but pure engineering magic. Kudos to the PS Audio team for coming up with such a simple yet ingenious design. In my world of 30-somethings, there are a ton of people interested in high-end audio but don’t want to spend 10k on an amplifier. Well, this is the amp that I recommend every time.
The Audio Beat
“…I could not fault the sound of the Gain Cell DAC — its neutrality and honesty were captivating, leading to compelling listening. During my time with it and the pair of M700s, I always felt they had total control over whatever music was thrown at them, in whatever format. From the understated nuance of an unaccompanied lute to the bombast of a symphony orchestra going full tilt, the laid-back drive of dub or the pulse of electronica, I not once felt deprived of any of the music’s emotion, rhythm, dynamics or detail. Whether using planar, stand-mounted or floorstanding speakers, I knew I would be rewarded with music free of noise, artifact or boredom. Used together, the Gain Cell DAC and M700s represent an intelligent, cost-effective entrance into high-end audio’s top tier….
“The PS Audio Stellar Gain Cell DAC and M700 mono amps took my system to a level that, with some recordings, was eerily close to the real thing. Paul McGowan and his crew in Boulder should be beaming with pride over the superlative performance of these components. Those making a first purchase or those seeking to upgrade must audition these electronics or risk having spent hard-earned money foolishly elsewhere.”
PS Audio has been on a roll. That roll continues with the Stellar M700 power amplifier. I have had nothing but good experience with PS Audio products; still, with the Stellar M700, my expectations were exceeded. Having little sound of its own, the M700 delivered well-balanced reproduction that was always faithful to the music… the Stellar M700s came ever so close to matching the sound of my high-end reference monoblocks, Theta Digital’s Prometheuses—which are ranked Class A in “Recommended Components” and, at $12,000/pair, cost four times as much as the PS Audios. The Stellar M700 is an outstanding bargain.