Solid State Preamp Reviews

Jason Victor Serinus auditioned the Michi P5 in September 2022 (Vol.45 No.9):

When Rotel shipped the Michi S5 stereo amplifier to me for review (footnote 1), they sent along a sample of its companion stereo preamplifier, the P5 ($4299.99, serial number 255-9501002), so that I could experience a complete Michi pairing. After a brief listen to that Michi combo, I decided to pair the S5 with my familiar reference for that review, the two-piece D'Agostino Momentum HD preamplifier ($42,500) and write a separate follow-up to Ken Micallef's November 2020 review of the P5.

Whereas Ken's review was heavy on vinyl, this follow-up relies exclusively on digital sources. That's not because I consider one source superior to the other; rather, because I lack sufficient space for a vinyl rig and records, my system only plays files, Tidal and Qobuz streams, and occasionally silver discs. This works quite well with the P5, which comes with a built-in DAC that, through its USB input, decodes PCM up to 32/784, DSD up to DSD128, and MQA.

While the P5 also includes optical (TosLink) and electrical (RCA) S/PDIF inputs, only USB accepts the highest sample rates. What's more, as John Atkinson wrote in his Measurements sidebar, the P5's USB input offers the best jitter rejection of the three digital input types (footnote 2). Hence, I stuck with USB.

In place of the laptop Ken used as a digital data source, I used a Roon Nucleus+ music server/streamer powered with a Nordost QSource linear power supply, with a QRT QSource DC connector cable, to source files from USB sticks and streams from Tidal and Qobuz. Streams were transmitted over multimode duplex fiberoptic cable from the modem entering the house to my listening room, where a Sonore opticalRendu with a Sonore linear power supply converted the optical signal to USB; the USB signal was fed to either a dCS Rossini DAC/Clock or the P5's internal DAC. All cabling to and from the P5 and Momentum HD preamps was Nordost, and the preamp supports (for both preamps) were Wilson Audio Pedestals.

Before I wrote the S5 review, I Zoomed with Daren Orth, Rotel's chief technology officer. In addition to sharing the same technical information included in Ken's review, Orth noted that the P5 uses two independent power transformers, one each for analog and digital. The P5 also includes 17 separate voltage regulators serving its DAC, preamp, and headphone sections. The P5's DAC is based on two AKM 4495SEQ chips, of which Rotel has sufficient supply (footnote 3). The two DAC chips feed their signals through fully differential, fully discrete class-A preamplifier circuitry.

"The Michi P5 utilizes a Muse S72320 volume controller," Orth wrote in a follow-up email. "Volume is managed in the analog domain within the chipset with digital controls from the main CPU. Step sizes start at 2dB at the bottom end (lower volume numbers) and reduce to 1.5dB then to 1dB, and finally to 0.5dB steps at the higher end of the scale (above volume-level 67) for finer control. We found this ramping method the most usable and efficient, providing exceptional control where the 0.5dB steps matter most."

Once the S5 began sending signal through my reference D'Agostino Progression M500 monoblock amplifiers to the Wilson Alexia 2 loudspeakers, the volume never got loud enough to sample the 0.5dB-step range, but I never felt I needed volume steps finer than the 1dB increments allowed.

Listening
I began with the Akademie für Alte Musik Berlin's relatively new, exceptionally colorful Harmonia Mundi recording of J.S. Bach's Brandenburg Concertos (24/192 WAV). First, I used the dCS Rossini DAC/Clock combo to send signal to the P5's analog inputs. The sound was impressively full and engaging, and the soundstage was almost as large as through my reference preamp. But the riot of color and timbral contrasts at the start of the first concerto, which is balanced by as full and sonorous a bass foundation as period instruments can produce, was toned down, with transparency less than with my much more expensive reference D'Agostino preamp.

To further explore transparency, I chose Debussy's colorful Trio for Flute, Viola and Harp on a wonderful Erato recording, Debussy: Sonates & Trio (Tidal 24/96 FLAC MQA). The recording was made in the resonant Salle Colonne in Paris and captures impressive depth and space between instruments. The P5 delivered a good representation of depth, texture, and detail, but the space between notes was gray rather than black. Regardless, I found myself deeply engaged with the music. Rather than listen to brief snippets from the first and third movements as planned, I sat transfixed through the entire 18-minute piece. The P5 was the first component I've reviewed in quite some time whose sound cajoled me to ditch reviewer mode and revel in the music—in this case, in Debussy's late career brilliance—time and deadlines be damned.

Tasked with reviewing the new Pentatone recording of Blue (24/96 WAV), Jeanine Tesori and Tazewell Thompson's brilliant, award-winning opera about race and violence in America, I used the Rossini DAC/Clock to audition Act I with the Momentum HD preamp and Act II with the P5. Music and sound were so mesmerizing that, midway through the second act, I realized I'd forgotten which preamp I was using. This is not to obviate the reality that the P5's presentation was, comparatively, less than maximally colorful and lacking inner illumination compared to the much more expensive D'Agostino; rather, it underscores how well the P5 can deliver the essence of fine music's expressive heart.

As I scribbled "so beautiful and moving" in my notes and sat up taller at the fascinating percussion that introduces the line "Kneaded, pinched, and prodded," I knew the Michi preamp was delivering what composer and librettist wished to communicate when they took Blue to the stage. In fact, it delivered music and words with far more color, power, and nuance than I experienced in the balcony of Seattle's McCaw Hall during the Seattle Opera's live presentation of Blue last season. Ultimately, it was the recorded presentation, heard through the P5, that moved me the most. Which is not to discount the power of the visual presentation, teeny as it was from the balcony.

When my friend Scott Campbell paid a visit, I switched between the Rossini DAC and the P5's internal DAC. Scott requested David Crosby's friendly "Laughing" from the 50th Anniversary Edition of the 1971 album, If I Could Only Remember My Name (24/96 FLAC, Atlantic/Qobuz). I confess that, despite multiple listens, I have yet to focus on Crosby's words; it's his amiable energy that continues to draw me in. Compared to the P5 DAC's presentation, the Rossini offered a significantly wider soundstage, a weightier midrange, tighter bass, and fuller accompaniment. Key to the recording's impact was a mellow midrange that the Rossini notably filled out. But both delivered the emotional warmth that makes this track a winner.

Time had come to up the ante with the room-shaking, deep organ pedal and brass opening of Richard Strauss's tone poem, Also Sprach Zarathustra. We followed that with the profound combination of blaring trumpets, fff bass drum, clarinet, piccolo, and double bass in the "Urteil und Hinrichtung" movement of Till Eulenspiegel's lustige Streiche—both works from 24/96 files, supplied by DG, of the Andris Nelsons Strauss box that was our Recording of the Month in June (7CDs, DG 486 2049). This is some of the most accessible, colorful, grandly romantic music ever composed for orchestra. Many of Strauss's surging passages and grand climaxes were intended to sweep you off your feet, lift you up, and carry you away with their size and beauty. And sweep us up they did, regardless of DAC or preamp.

We ended with the devastating second movement of Shostakovich's Symphony No.11, with Nelsons conducting the Boston Symphony Orchestra (24/96 FLAC, Qobuz). "That must be one of the best recordings ever made!" Scott exclaimed after a huge battery of brass, bass drum, snare, and timpani depicted the brutal massacre of unarmed peasants and priests by the Czar's Cossacks. Lesser speakers than the Wilsons weep at such assaults.

Sure, the dCS Rossini is a better DAC, and the D'Agostino Momentum HD a better preamplifier. Of course their pairing delivered more microdetails, color, and full-range sound. But we're talking about components with a combined price of nearly $80,000—almost 20 times the price of the $4299.99 Rotel Michi P5, which also includes, in addition to the linestage and DAC, a headphone amplifier and an MM/MC phono stage.

Where the P5 equaled the dCS Rossini DAC/Clock and D'Agostino Momentum HD was in its ability to capture my attention and move me. Even lacking the level of detail, refinement, and natural-sounding top-to-bottom coherence, the Michi P5's presentation touched me to the core. It filled me with the gift of music and moved me as much if not more than at some live performances.

The Michi P5 is far more than a "good for the price" component. When I played gripping music through it, it grabbed me by the gut and propelled me to a realm of emotional truth. If that's what you want when you listen, by all means give it a thorough audition.—Jason Victor Serinus

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Footnote 1: Also see Michael Fremer's rave review of the Michi M8 monoblock.

Footnote 2: The P5 also does Bluetooth, AptX plus AAC.

Footnote 3: Production at AKM has only recently started up at the new factory, following a disastrous fire. See our report in the July 2021 issue.