PS Audio Stellar M1200 monoblock power amplifier Page 2

"Punchy" doesn't begin to describe the M1200's low-end solidity, extension, rhythmic swagger, and complete freedom from overhang. I played a plain American pressing of David Bowie's Station to Station (RCA APL 1-1327); following the train drive-by, George Murray's bass line kicks in, followed by a single Dennis Davis drum "thwack" that felt as if the woofer cones might have broken free of the baskets if I had played it much louder, taking the surrounds with them! The energy concentration on and around individual notes was one of the M1200's most memorable characteristics.

The middle and above
The M1200 was as fast, precise, and clean from the mids on up as it is in the bottom octaves, which helps ensure a bottom-to-top rhythmic coherence and transparency that lets you "see" into the farthest reaches of the soundstage on recordings that can produce such a 3D picture. Transients were lightning-fast, pure, and precise. You'll not detect grit, grain, smear, or "etch" unless it's baked into the recording.

Class-D objectors point to sonic issues in the upper midrange and above. That's where the noise and objectionable glare and "ringing" ride.

Yet, when I compared the old Classic Records reissue of Big Star's jangly and bright #1 Record (ADS 2703) with a recent one from Craft Recordings (CR00211), the amp's ability to dissect and cleanly present, without glare or smear, all of the high-frequency transient elements—wiry electric guitars, tinkly piano, and drums—was as good as I've ever heard. The amp also made clear the differences between the masterings: Jeff Powell's recent one, from his Take Out Vinyl Mastering in Memphis, adds a pleasing touch of mid-bottom emphasis.

By the time you read this, vinyl-only subscription jazz label Newvelle Records will have released The New Orleans Collection, a four-LP series recorded early in 2020 at Esplanade Studios, a fully restored-and-renovated church in the Treme neighborhood of that city. Among the four is pianist Ellis Marsalis's final recording, made just before he contracted COVID-19 and passed away. On a few tracks, he's joined on vibraphone by his youngest son, Jason.

The piano's upper register and the entire vibraphone range are where a class-D amp's problems should exhibit themselves most clearly. And they did, but only slightly and in a way that was not highly objectionable. The combination of vibraphone and piano on a wonderful rendering of John Lewis's Django—still on the Marsalis recording—presented a serious challenge to transparency and especially to vibraphone-decay cleanliness. The piano sounded fine in the lower registers, but as the late Mr. Marsalis ventured farther up the keyboard, there was a slight "ringy" quality, a glare or glow around the notes, like a parasitic halo. The vibraphone had it throughout its range, combined with a blunt and less-than-satisfying roundness to what should be a shimmering bell tone. (Also, I wish the engineer hadn't spread the vibes across the soundstage! It was like a '50s-era ping-pong effect, and damn distracting!) A heartbreaking take on "For All We Know" followed that had me forgetting about ringy vibe notes and remembering the tragedy of Mr. Marsalis's passing.


I hadn't played this record before, so to be sure I was hearing the amp and not the recording, I played my favorite MJQ "Django," from The Modern Jazz Quartet, European Concert (Atlantic 2-603), a record I've been playing since the early '60s. The first thing I noticed was Connie Kay's brushwork center stage: the cleanest and most transparent rendering of it I've ever heard! Convincingly metallic, not too sharp or bright, not edgy, but "in the pocket." The cymbals were finely placed in space, too.

The vibes and piano, though, were not quite right, and not what I was expecting. The attacks were clean, but the sustain was stifled and blunted, after which the decay dropped off a cliff. The piano and especially vibe notes had a one-dimensional quality: flat, not round. This was a quality I'd noticed on another record I've often referred to in reviews: John Renbourn's Sir John a Lot (Transatlantic TRA 167). The track "Forty-Eight" features the most delicate glockenspiel strikes and finger cymbal touches, which appear to hang in 3D space and should shimmer, ring, and decay. Instead, the transient, while clean, was followed by almost a wood-block sound instead of a metallic, bell-like sound. Yet the reproduction of Renbourn's guitar was superbly transparent, clean, and faultless.

Despite this, the words that best describe this amplifier are "sweet" and "highly resolved." That sounds like a contradiction, but not really. Violinist Ruggiero Ricci's Virtuoso Showpieces (London Treasury Series STS 15049) could not have sounded sweeter or more transparent and artifact-free. Mr. Ricci's pizzicato plucks were as honestly rendered as I've ever heard them. Ernest Lush's piano, positioned well behind the violin, was somewhat more opaque, but that's the nature of the recording; it did not excite the aforementioned glare. Nor did many of the records and hi-rez files I played, though I noticed it on Lang Lang's recent Goldberg Variations (DG 481 9701 4 CDs), especially on the live "one take" performances recorded in the reverberant St. Thomas Church in Leipzig, though low-level playback helps a great deal and allows the amp's speed and transient precision to overcome to a great degree that glare or glow.

I haven't mentioned dynamics. With stupendous bass performance, ferocious driver grip, and 600 watts into 8 ohms and 1200 into 4 ohms, this amp is a dynamics monster. It also delivers spaciousness when it's on the recording.

When I switched back to my reference amps costing around 20 times as much as the M1200s and continued playing the Goldberg Variations, the differences in microdynamic nuance—the small, low-level dynamic shifts that make music sound "live"—were dramatic. The church space, not that glare or glow, was present around the notes that swelled and ebbed more naturally. The piano's harmonic envelope was far more nuanced, so the instrument sounded more like a piano and less like a harpsichord. Incidentally, there's a great photo in the booklet of Lang Lang, eyes closed, listening to something—but neither the Revox B-77 nor the turntable (sorry, don't recognize, but I think there's an SME Series III arm on it), nor the vacuum-tube amp, appeared to be turned on. Maybe it was a photo shoot set up to excite people like me. It worked.

Can you name another $6000/pair amplifier that outputs 600/1200W, delivers this kind of bottom-end extension, control, slam, and precision—and also produces a chameleon-like sweetness when appropriate? I know I can't. It would be nice to have a pair of these around just to plug in when playing rock music. The sound of Wayne Shorter's classic solo on "Aja," from the album of that name (ABC AA-1006), and everything else about that song and album as reproduced by the M1200s will be sorely missed now that the pair of Stellar M1200s are packed up and heading for that great measurement heaven in the sky—well, Brooklyn, actually. It will be interesting to see how the designer dealt with class-D's major measured weakness: noise.

Substituting the $5998/pair PS Audio Stellar M1200s for my reference darTZeel NHB-468s was like stepping out of a Mercedes-Maybach and into a Porsche Carrera S—though one miraculously priced like a Subaru. It was a month-long (plus a little more) fast-handling joy ride. I didn't even miss having a back seat or a big trunk because what these amps did well was so much damn fun and what they didn't do so well had to be tracked down and hunted with a sonic microscope.

Want a sonic checklist rating? Bottom end: A+, midrange transparency: A, high-frequency extension and freedom from grain and grit: B+, macrodynamic "slam": A, microdynamic delicacy: C, imaging and staging: B, timbral verisimilitude: Jekyll and Hyde, A or C, depending on the recording and the instruments involved. Maybe the M1200s were just too fast for their own good.

After the superclean attack, they went right for the too-fast decay and missed the sustain. While that often leads to "skeletal" sound, the M1200s never delivered bones, because the transients were never edgy or nasty. They were natural and just right. Still, I'd probably like the M1200s even more if they put on a little weight.

As I noted, the Ricci violin record sounded sweet. These amps can sound rich. They never developed an unwanted edge. They just didn't hang around and linger long enough on some things. Sins of sonic commission are far worse than the sin of stingy sustain omission.

The lightning-fast, clean transients, top to bottom, were consistently exciting and produced spectacular detail resolution. I remember one evening playing Eno's high-energy, high-speed "Third Uncle" from Taking Tiger Mountain (By Strategy) (Island UK ILPS 9309), an album I've been playing since 1974. About a quarter of the way in, I just started laughing. So much detail was unraveled and revealed. True, the other system components were doing some of the talking, but the amps did their part and for a fraction of the price of the rest.

Overall, then, despite my fault-finding, which is my job, designer Myers has certainly done his job: creating a small, lightweight, cost-effective, powerful miracle performer that's sure to find a vast audience, especially among a younger generation of audio enthusiasts, though I'm sure many oldsters will gladly hop in for the exciting ride.

PS Audio
4826 Sterling Dr.
Boulder, CO 80301
(720) 406-8946

ejlif's picture

I'd take a 911 S all day over the Maybach!

a.wayne's picture

Agree completely with MF assessment on the class D sound , Fast , punchy and very musical on recordings which changes direction and pace often, only to be let down by their poor timbre , especially on piano’s were everything sounds like a magical keyboard ..

Flatter to deceive they do very well ..!


sw23's picture

Nice review. But it seems like it would be more appropriate to compare this amp to conventional high powered budget offerings from Parasound, Bryston and Musical Fidelity than to a super amp. After all this is probably the choice confronting folks in this price class.

Bromo33333's picture

Agreed, we should at least know how it stacks up against similarly priced things.

Other reviews seem to notice similar issues that are cleared up by adding a tube damper and making sure the tubes are fully seated in their sockets. And a few hundred hours of burn in to let the vibrating elements find their seating. Some also have noticed that not stacking them helps, too.

Go figure. Sounds like a nice effort.

The reviewer wasn't all that happy, yet they rated it as a "class A" so I don't know what they are trying to say.

Ortofan's picture

... really are, especially compared to a pair of the NAD C298 amps, which use the Purifi amp modules and have a rated output in bridged-mono configuration of 1kW @ 8Ω and 1.1kW @ 4Ω - all for $4K/pair.

AnalogueFan's picture

mmm with more mmm .. will be enough for my WB Chimera .? I don't think they are enough, after this review.