Note: for the full suite of measurements from the SoundStage! Audio-Electronics Lab, click here.
When the Rotel Michi line re-emerged in 2019 after a two-decade absence, I was caught off guard. It’s not that I didn’t think I’d ever see a Michi product again—I didn’t know Michi existed in the first place! Mea culpa.
During the summer, I was surprised again when I was offered to review the new Michi flagship integrated amplifier-DAC, the X5 Series 2 ($7999; all prices in USD). The original X5 (reviewed by Roger Kanno in August 2021) was introduced in 2019; I didn’t expect an updated model so soon. It seems that after being off the high-end radar for 20 years, Rotel Michi is back with a vengeance.
I won’t delve into Michi’s history as it’s been expounded in some length by Edgar Kramer in a feature for SoundStage! Australia and Aron Garrecht in a blog piece for SoundStage! Global. In the simplest terms, Michi is the upper echelon arm of Japanese electronics manufacturer Rotel.
I recently spoke with Daren Orth, Rotel’s chief technical officer, and learned that resurrecting Michi was not the plan, at least not initially. As the story goes, Rotel spent two years developing a technology platform for a new product line. At first, Daren’s principal design objective for components based on this platform was simply to surpass the performance of Rotel’s existing products. Bolstered by his engineers’ confidence that they could do it, however, he became more ambitious and challenged them to go a step further and design these components to be revolutionary. The result exceeded his own expectations.
The new line of products was a significant step above Rotel’s other offerings in both performance and aesthetics (industrial design of the new components was commissioned to the well-known London-based firm Goodwin Hartshorn). It was distinct enough, it was felt, to merit a separate series label—and thus Michi was reborn.
When I read the press release for the X5 Series 2 integrated amplifier-DAC, I was amazed to read that the new model included a whopping total of 99 changes. My first thought was that perhaps they had rushed the original X5 out the door. But the reason, it turned out, was technical.
As Daren and his team began working on the next generation of Michi components, they experimented with DACs from several manufacturers. They eventually landed on the ESS Sabre ES9028PRO, a flexible eight-channel DAC that can be configured in stereo with four channels for the left audio signal and four for the right. It was the switch from the AKM DAC employed in the 2019 Michi series to the new Sabre chip that begot most of those changes. Initial implementation of the ES9028PRO didn’t sound good, Daren explained. Extensive modifications to the surrounding architecture were required to obtain optimum performance from this chip. It took a full year of collaboration between Rotel and ESS engineers to improve the peripheral circuitry. In the end, what Rotel achieved with the new DAC was a more precise sound and a lower noise floor than was possible with the DAC it supplanted, Daren told me.
Any description of the X5 S2 ought to start with a few words on its appearance. In a word, it’s gorgeous. Weighing 92.6 pounds and measuring 7.6″H × 19″W × 17.8″D, including massive side-mounted heatsinks that obviate the need for cooling fans, the X5 S2 is huge. But the handsome matte black finish of the casework, attractive glass front panel, and sharp TFT display give it a clean, modern look. It exudes quality without calling too much attention to itself.
On the front panel, flanking the high-resolution display, are two knobs, input selection and volume control, which feel solid and operate smoothly. A 1/4″ headphone jack and an On/Standby power button complete the front-panel interface.
On the back, eight hefty platinum-plated binding posts permit conventional and biwire modes. The back panel is incredibly tidy, with analog, digital, and speaker connections arrayed across three recessed rows.
The X5 S2 ships with an all-metal remote control with identical finish. It is clean and uncluttered, and its glossy black buttons are laid out in an intuitive pattern.
To feed the new DAC, the X5 S2 offers three optical (TosLink) and three coaxial (RCA) S/PDIF inputs, which can accept PCM data up to 24-bit/192kHz. Also available is a USB-B input, which supports Audio Class 1.0 (up to 24/96) by default but will also support Class 2.0 (up to 32/384) once the appropriate Windows driver, included on a flash drive, is installed. (MacOS supports up to 384kHz via USB Class 2.0 by default.) The USB input also supports up to DSD256. The X5 S2 is both MQA compatible and Roon certified, capabilities I don’t use and didn’t test.
A small antenna on the back of the X5 S2 hints at its Bluetooth streaming capability. AAC and aptX HD codec compatibility allows for improved Bluetooth sound quality. I normally use Bluetooth only for casual listening, with headphones or a portable speaker. I tried it—it worked—but didn’t use it for critical listening. While most owners are unlikely to use Bluetooth as a primary source, it’s a welcome convenience, particularly at a get-together, as it allows others to control the playlist.
The X5 S2 accepts analog signals through any one of four pairs of single-ended (RCA) inputs or a pair of balanced (XLR) inputs. A built-in phono stage (with a ground terminal) can accommodate a moving-magnet or moving-coil cartridge, but input sensitivity and impedance loading aren’t adjustable; they are fixed at 5.7mV and 47k ohms for the former type, 570μV and 100 ohms for the latter. I love listening to vinyl and was eager to test the X5 S2’s aptitude for it.
The X5 S2 shares much of its predecessor’s DNA, not the least of which are the dual low-noise toroidal power transformers, which are made entirely in-house, Daren proudly emphasized. Although outsourcing components such as these can reduce production costs, winding transformers in-house ensures consistency and quality, he noted. These transformers feed four 22,000μF high-efficiency storage capacitors, connected in parallel, that give the X5 instantaneous access to power. Daren likened the effect of these capacitors to the acceleration ability of an electric vehicle: a gas-powered vehicle, even a high-performance one, takes a bit of time to accelerate when the driver guns it; an electric vehicle responds almost instantly. With so much reserve power, the output stage of the X5 can start and stop rapidly. The Michi is the “EV of audio,” Daren quipped.
The X5 S2 boasts a mammoth output of 350Wpc into 8 ohms, not quite doubling to 600Wpc into 4 ohms. I won’t see the measurements until this review is published, but considering that according to our own measurements, the performance of the original X5 easily bettered its published specifications, I have no reason to doubt these specs. (I applaud companies that specify their wares conservatively!) Michi’s new X5 S2 should be at least as capable as the original X5 and should be able to drive all but the lowest-impedance speakers to high volumes even in large rooms.
A preamp output is available to bypass the amplifier section and send the source signal to an external amplifier. A pair of mono sub outputs, each summing both channels, allows one or two subwoofers to connect with the X5 S2.
Integration with an automation system is possible via an RS232 port and a DB9 serial cable or by an ethernet port, which can also be used to link to a network and download software updates. A powered USB port can also be used for software updates (or to charge USB devices).
A 12V trigger powers up the X5 S2 when a compatible connected component is powered up. A 3.5mm jack for an external IR sensor comes in handy when the unit is placed in a cabinet where its built-in sensor, on the front panel, is blocked. A standard IR receiver wired to this jack can be placed where reception is available and relay command signals from the remote to the unit.
The X5 S2 was too large for my equipment rack, so when Sheldon and Jeff Ginn of Kevro International (Michi’s Canadian distributor) dropped it off at my place, they were kind enough to not only carry it downstairs and set it up for me but to also bring with them a Norstone amplifier platform, so the Michi wouldn’t be sitting on the floor. Setup was typical and straightforward: I connected my sources and speakers, and everything worked without issue.
The X5 S2’s functionality can be customized extensively. One can rename inputs, set a fixed input level, and bypass the tone controls, as well as disable inputs that aren’t in use (which I did almost immediately since I didn’t need most of them). An absolute maximum can be set on volume level, as can the maximum volume immediately after power up. With digital inputs, Signal Sense mode, when activated, can monitor the data stream for an audio signal. If no signal is detected for ten minutes, the unit enters a power-saving mode but will turn on again as soon as a signal is detected. Display brightness is adjustable and can be set to function either as a stereo VU meter or as a spectrum analyzer. I tested this feature briefly but disabled it for the audition as I found the visualizations distracting. A feature I did appreciate, however, is the display of sample rate and word length that accompanies digital input.
The Michi replaced my Bryston B135 SST2 integrated amplifier and was connected to a pair of fifth-generation Monitor Audio Gold 300 floorstanders with Nirvana Audio Royale speaker wires. An NAD C 565BEE CD player was linked via an i2Digital X-60 coaxial cable to a Bryston BDA-2 DAC, which in turn was wired to the X5 S2 with Nordost Quattro Fil RCA cables. A Thorens TD 160 HD turntable armed with a modified Rega RB250 tonearm and a Sumiko Songbird low-output MC cartridge enabled vinyl playback. A Pro-Ject Audio Phono Box DS3 B phono stage (and Power Box S3 Phono outboard power supply) was connected to the Thorens with generic RCA cables. The DS3 B sent analog signals to the X5 S2 through a Kimber Kable Tonik cable. When the X5 S2’s onboard phono stage was used, the TD 160 HD was plugged directly into it via the generic RCA cables. An ExactPower EP15A power conditioner/regenerator empowered all electronics.
As I did for my recent review of Hegel Music Systems’ H600, I began by playing music through my Bryston BDA-2 DAC, which was connected to one of the Michi’s line-level inputs. I wanted to first assess the X5 S2 purely as an integrated amplifier before evaluating its digital capabilities with the onboard DAC.
Sheldon told me the X5 S2 already had around 70 hours of use prior to arriving at my place, so I just let it warm up for a short while and began my audition with little delay. Among the first albums I played was Tori Amos’s Boys for Pele (CD, EastWest Records A2 82862), one of my standard audition recordings. The opening track, “Horses,” features Amos’s voice and piano, which begins rather starkly with a single note repeated for nearly two minutes. It’s the sound of the piano that gives this recording its depth, and the X5 S2 conveyed this sense of spaciousness strongly.
“Professional Widow” has a similar section, vocals with piano accompaniment, and again I could vividly sense both parts hanging in space on a large and deep stage. Over a wide range of material, I consistently found an immediacy to the Michi’s presentation that made my Bryston integrated amplifier seem laid back.
On “Father Lucifer,” the multi-tracked vocals were crystal clear, highly articulate, and sharply outlined across the front of the room, extending from speaker to speaker. When the trumpet played, it was imaged farther back on the stage than I’m used to with this recording, conjuring up a deeper soundstage still. Vocals, piano, bass, and other instruments—everything was incredibly well delineated. The X5 S2 was also extraordinarily revealing, uncovering everything this recording had to offer. It was difficult not to stop what I was doing and focus on that sound; it commanded my attention.
I then switched to another of my standard audition selections, Belkis, Queen of Sheba from an album of Ottorino Respighi’s orchestral music by the Minnesota Orchestra conducted by Eiji Oue (CD, Reference Recordings RR-95CD). The rapid-fire tempo and exhilarating dynamics of the third movement, the powerful “War Dance,” was delivered with ease by the Michi, imbuing the piece with unsettling urgency. The Minnesota Orchestra was spread before me across a wide, deep soundstage, and I was right there, sitting a few rows back from center stage at Orchestra Hall in Minneapolis, where it was recorded.
Years ago, when I first heard Belkis, Queen of Sheba, it was the fierce “War Dance” that made the greatest impression on me. One needn’t look past the title to know that this music encourages loud playback, and now, with 350Wpc at my disposal, I took liberties with the volume. The outcome was predictable: my ears tapped out well before the X5 S2 showed any signs of strain or any change to its sonic character. It didn’t waver, maintaining clarity and strong bass up to as high a volume as I dared to take it.
The X5 S2’s bass reproduction was exceedingly good, which can probably be attributed to its enormous power reserves. In album after album, the X5 S2 delivered exceptionally powerful, tightly controlled bass. The Monitor Audio Golds are each rigged with a pair of 8″ drivers and can dig pretty deep when called upon. The X5 S2, through the Gold 300s, energized my listening space with clean, potent bass without a flinch. It aptly delivered the pounding rhythms of the piece to great dramatic effect.
Of the many requiems in the classical canon, Mozart’s quintessential work is doubtlessly the most popular. Another well-loved requiem is Gabriel Fauré’s. Whereas Mozart’s musical setting is terrifying, Fauré’s is as gentle as a lullaby—indeed, it was described by the composer as a “lullaby of death.” My recording of this work, featuring the Corydon Singers and English Chamber Orchestra conducted by Matthew Best (CD, Hyperion, CDA66292), was rendered beautifully by the Michi. I particularly enjoyed the gorgeous, ethereal vocals which lend this recording an aura of space that is reflective of the superb acoustics of the recording venue, the Church of St. Jude-on-the-Hill, in London. Fauré’s Requiem is so full of light and hope, it’s the complete opposite of Mozart’s foreboding work. The X5 S2, with its neutrality and low noise, stepped out of the way and allowed me to experience this performance fully, as recorded.
After getting a sense for how the X5 S2 performed with the Bryston DAC, I continued my audition using its onboard Sabre DAC.
I began with “Your Rocky Spine,” from Great Lake Swimmers’ Ongiara (CD, Nettwerk 30691 2), recorded in London, Ontario’s Aeolian Hall. It is a wonderful album, in both music and sound. The DAC-empowered X5 S2 painted a clear sonic picture of the performers in distinct outlines across the front of the room. Musicians’ images were unambiguous with both DACs, however, and instruments’ tonalities were indistinguishable between them.
The one aspect of presentation that differentiated the Bryston DAC from the Michi’s was the imaging of the acoustic space, which was more perceptible with the Michi. Instruments had more air around them, and the reverb of the venue was more apparent. The Michi may be quieter than the Bryston, which may have contributed to this perception, but I’m not sure that it is. This was the sole distinguishing characteristic between the two DACs, inasmuch as I could tell, but the difference was subtle. Moreover, that enhanced perception of space the Michi’s DAC induced wasn’t always there.
On “Plainchant: Pange lingua,” from The Tallis Scholars Sing Josquin (CD, Gimell CDGIM 206), for instance, the two DACs were indistinguishable to my ears and portrayed equally well the vast acoustic space of Merton College Chapel, in Oxford, where the recording was made. Engrossed in this beautiful music, I was wholly transported to a back pew in that ancient chapel where the distant, otherworldly voices seemed to magnify the grandeur of the space. The exquisite serenity of the piece was communicated superbly by both DACs.
On the Mule Variations by Tom Waits (CD, Anti-/Epitaph Records 86547-2), I was treated to a highly musical, richly detailed presentation by both DACs. Waits’s voice sounded gruff, his guitar incisive, and the bass full-bodied. Again, my perception of space was somewhat greater with the Michi’s DAC than with the Bryston DAC, but otherwise, I found it difficult to distinguish between the two; they had very similar sonic attributes. If I were to choose one over the other, I’d opt for the Michi, but frankly, I’d be happy with either. Put another way, if I owned the X5 S2, I’d sell my BDA-2.
Onboard phono stage
I started by listening to Massive Attack’s Protection on CD but ended up switching partway through to vinyl (LP, Circa LC 3098). Protection sounds good on CD, but I prefer its warmer vibe on vinyl and used it to test the Michi’s built-in phono stage.
With Pro-Ject Audio System’s DS3 B and Power Box S3 Phono outboard power supply pulling phono stage duty, the meaty bass on “Better Things” caught my attention instantly. It provided a solid foundation for the track. Tracey Thorn’s voice, on the left channel, was remarkably clear; the softest of sibilants were easily heard. The Pro-ject phono stage is so quiet and revealing, there was nowhere for sibilants to hide.
The jungle vibe of “Karmacoma” was expansive and, again, grounded by deep, warm bass. Gloomy effects from the back of the stage underscored the murky atmosphere and, especially on vinyl, this made for a fuller presentation. On CD, “Karmacoma” had punchier bass and tidier sound overall. Sibilants were dulled on digital, making Thorn’s vocals sweeter sounding.
Switching to the Michi’s phono stage proved interesting. The first thing I noticed is that it offered plenty of gain; I had to dial back the volume considerably to compensate. The second thing I noticed is that it sounded pretty darn good. When I was familiarizing myself with the X5 S2’s functions, I noted that there was no option to change capacitance and impedance loading on the phono stage. It turns out, however, that it pairs extremely well, out of the box, with the Sumiko Songbird Low Output MC.
Like the Pro-Ject phono stage, the Michi’s delivered strong, warm bass and lucid vocals that seemed to pop out from the mix. Its vinyl presentation had the same kind of immediacy I heard listening to CDs. The Pro-Ject phono stage had a cooler demeanor. Thorn’s voice on “Protection” was farther back on the soundstage, and the whole presentation sounded a bit more laid back. Both phono stages sounded clean, and unless you prefer lusher sound, each has its appeal. If I owned the X5 S2 I would still use the DS3 B phono stage, though. As much as I love vinyl’s inherently warm, inviting sound, I still crave detail, which the DS3 B made more readily apparent.
Moving on to the Prelude from Georges Bizet’s opera Carmen (LP, RCA Victor LM-6102), the X5 S2’s presentation with the Pro-Ject DS3 B was sharper than with its own phono stage. The RCA Victor Orchestra was laid out more distinctly on the soundstage, better outlined, its strings section more focused. With the built-in phono stage, images were a touch rounder, a tad fuzzier. Still, vinyl playback on the Michi using its onboard phono stage was thoroughly enjoyable—more so than I had expected. If I were buying the X5 S2, I’d feel no rush to add an outboard phono stage.
I would have liked to compare the Michi X5 S2 side by side with Hegel Music Systems’ H600 integrated amplifier ($12,500), which I reviewed earlier this year; unfortunately, I had to give it up some time ago and return it to the manufacturer. Instead, I pitted the Michi against my Bryston B135 SST2 integrated amplifier (discontinued; $4695 in 2013). While available, the B135 SST2 could be had with an optional DAC module ($1395), a moving-magnet phono stage ($600), and a remote control ($375). It has since been replaced by the B1353 ($6995; add $750 for optional DAC module and $1000 for optional MM phono module). A fully equipped B135 SST2 cost a little over $7K and offered many of the essential features of the X5 S2, though not its power.
Rated at 135Wpc into 8 ohms, the B135 SST2 has nowhere near the power output of the Michi, and this became apparent at high volumes. Returning to Respighi’s “War Dance,” the B135 didn’t exactly struggle (i.e., clip) at high volume levels, but it lacked the sense of ease the X5 S2 projected. High-powered amplifiers often sound like they aren’t working too hard when pushed to play loud. This effortlessness was patently evident with the Michi; its sound character didn’t change at high volume. With the Bryston, that wasn’t quite so.
On Boys for Pele, the Michi’s presentation was more upfront than the Bryston’s; performers were a touch closer to the listening chair. This made tracks such as “Horses” and “Professional Widow” instantly gripping. I’m not sure which integrated amplifier was more accurate, but I certainly found the Michi’s sound to jump out at me more, but not to the point that it was fatiguing. In level of detail, I found the two amps to be similar. These are both well-designed class-AB amplifiers, and they had much in common at normal listening levels. But the Michi, being a brand-new design—the B135 SST2 came out 10 years ago—pulled ahead with its greater power, broader connectivity, and more luxurious industrial design. And it costs only $1000 more than what the Bryston did in 2013. The Bryston is made in Canada, which may be a factor to some prospective buyers, and it carries a 20-year warranty; the Michi is manufactured in China and carries a five-year warranty. But otherwise, the Michi offers more for the money.
As someone who has heard his share of integrated amplifiers—I’ve been reviewing components since 2006—I can say unequivocally that Michi’s X5 S2 offers a lot for the money. I wouldn’t have been surprised if I had been told that it cost $15K. There are integrated amplifiers on the market with a larger set of features: room correction, bass management, and network streaming, among others. However, apart from Musical Fidelity’s M8xi (reviewed by Roger Kanno in 2020), which boasts a whopping 550Wpc into 8 ohms and an obscene 870Wpc into 4 ohms, no other integrated amplifier that I am aware of can claim 350Wpc into 8 ohms and 600Wpc into 4 ohms. With its power and premium parts and design, that the Michi X5 S2 sells for $8K has me shaking my head in disbelief. If you’re in the market for a high-powered integrated amplifier with a top-notch DAC and phono stage that rival standalone separates, the Michi X5 S2 is peerless.
. . . Philip Beaudette
Note: for the full suite of measurements from the SoundStage! Audio-Electronics Lab, click here.
- Speakers: Monitor Audio Gold 300 5G.
- Integrated amplifier: Bryston B135 SST2.
- Digital sources: NAD C 565BEE CD player, Bryston BDA-2 DAC, Bluesound Node 2i streamer.
- Analog source: Thorens TD 160 HD turntable, Rega Research RB250 tonearm, Sumiko Songbird MC cartridge.
- Phono stage: Pro-Ject Audio Systems Phono Box DS3 B and Power Box S3 Phono outboard power supply.
- Speaker cables: Nirvana Audio Royale.
- Interconnects: Nordost Quattro Fil (RCA), Pro-ject Connect it Phono RCA CC, Kimber Kable Tonik (RCA), generic RCA.
- Digital links: AudioQuest Forest (TosLink optical), i2Digital X-60 (coaxial).
- Power conditioner: ExactPower EP15A.
Rotel Michi X5 Series 2 Integrated Amplifier-DAC
Warranty: Five years, parts and labor.
Tachikawa Building 1F
2-11-4, Nakane, Meguro-ku
Tokyo, Japan 152-0031
Fine Sounds Americas
11763 95th Ave N
Maple Grove MN 55369
Phone: (510) 843-4500
Kevro International Inc.
902 McKay Road
Pickering, ON L1W 3X8
Phone: (905) 428-2800