Tube Preamp Reviews

This unusual concerto, one of only two composed by Ravel, premiered in 1932 and is distinctive in many aspects (ie, it has only a single movement, and the piano is played with only the left hand). The concerto begins with what some at its premiere must have thought was the orchestra tuning up. By the time Franáois hammers down his first notes, the audience's collective mind was probably confused and delirious. The piano sound on this recording is dark, heavy, and extraordinarily dense, but the RP-1's MC stage and the Hana EL helped a lot by digging down to the composition's core intentions and letting the powerful deep bass, rapidly shifting momentums, and high-energy highs voice their mad Parisian counterpoint with stupefying lucidity.

[long pause]

Wow! That was nice!

Listening: with the PrimaLuna ProLogue Premium
Any slight dryness I might have sensed with the 25Wpc First Watt J2 disappeared when I inserted PrimaLuna's 36Wpc, push-pull, EL34-tube ProLogue Premium ($2199; review on the way). Suddenly, there was moisture on the face of my Kool-Aid pitcher and dewdrops on trumpets and trombones. The word liquid describes the effect this preamp-amp combination had on the music's movement and flavors.

The Rogue RP-1 and First Watt J2 were all about articulation and joyous forward momentum. In contrast, the combination of Rogue and PrimaLuna directed my attention below the music's surface: to the obscured eddy currents and rhythmic riptides that enhance music's core excitements. This combination had a way of pointing out compositional eccentricities. It could also get it going . . .

AM, 2M, MM & ML
"Wind it up, baby! Shake it for your daddy!" Tell me they didn't amp up the midrange on those 7" 45rpm singles. Maybe they cut the grooves deeper? Whatever they did, if you want to fully enjoy your favorite music from the 1950s and '60s, I promise you: 7" discs with big holes are stronger, punchier, more richly toned than any HD, Tidal, or Pono facsimiles. (They look and feel good, too.) The force of their presentation reminds me fondly of AM radio and jukeboxes. The Rogue RP-1's moving-magnet phono stage, fed by the new Technics SL1200GAE turntable and tonearm with Ortofon 2M Black cartridge, made my youthful hot-rodding exploits seem real again (think smeared lipstick and handcuffs). I played Matt Lucas's version of the Hank Snow classic "I'm Movin' On" (7" 45rpm, Smash S-1813) over and over, until my upstairs neighbors stomped on their floor. What I'm trying to say is, the Rogue's MM phono stage was true of tone, fast, and lively—it will make you move, "get rid of these blues!"

You want to know how good your hi-fi is? Then forget those Eagles in Famous Windbreakers and play some crazy hyperdynamic shit. Let hell break loose and see if your stereo can handle it. With exactly that thought, I played Volume Two of the music composed by my Australian friend J.G. Thirlwell for The Venture Bros. (LP, Ectents LP 37), an animated TV series that appears on the Cartoon Network's Adult Swim. In addition to composing for his band Foetus and the likes of Nick Cave and Kronos Quartet, Thirlwell produces, arranges, and collaborates with Nine Inch Nails, Pantera, and others. It would take a thousand words to list all the instruments, sound effects, and samplings on this full-tilt force field of a soundtrack album—but the Hana, the SL-1200GAE, the Rogue, the ProLogue Premium, and the Zu Audio Soul Supreme speakers sailed right through this hair-rising musical apocalypse. I experienced nine octaves of well-toned, well-sorted musical force. I'm not sure why, but all through my listening for the RP-1, I found myself drawn to big, complex, hyperdynamic music, and always came away impressed by the Rogue's lucidity and composure under duress. Next, I thought I should hear how it did with some quiet, sanctified music.

Line only with CD
I was never a Lutheran, but somehow I ended up attending a Lutheran elementary school where, two hours a day, six days a week, for seven years, I was forced to sing soprano in the church choir. Along with cars and chemistry, singing became an essential part of my identity—until my voice began to change. But during my church period, I learned to respect the Protestant spiritual viewpoint, and developed an everlasting love for the music of J.S. Bach.

Most of my record collection and more than half of my listening involve what I call church music. Using my hi-fi to experience the sacred music of all cultures has become my personal form of church (used as verb, adjective, and noun). Just so you understand: Aretha Franklin, Ralph Stanley, and the Reverend Al Green are all ministers of my church.

Not infrequently, this listening-room church I attend employs choir, soloists, pipe organ, and the scores of organist-cantor-composer J.S. Bach. Sacred mass during this review period usually included the 46 chorale preludes with organ that comprise Bach's Orgelbüchlein, BWV 599–644, performed by the Ensemble Mare Nostrum under Andrea De Carlo (CD, M•A Recordings M076A). Each prelude is like a dream or an inspired prayer. This is an elegant production of the Little Organ Book; M•A's producer-engineer, Todd Garfinkle, has enhanced Bach's uplifting qualities with a most perfect digital recording.

I drove the Rogue RP-1's 12AU7-tube line stage with Schiit Audio's Bifrost Multibit DAC ($650), and with every pair of speakers I tried, I choked up when boy soprano Simon Bomon sang "Liebster Jesu, wir sind hier!" (Dearest Jesus, we are here!)

Because this disc is so artfully recorded, it's a good test for low distortion and purity. To easily differentiate between Bomon's voice and the ethereal adult female soprano of Celine Scheen is a minimum requirement for enjoying this music—as is recognizing the multiple bass viols and the archlute. The string parts provide a poetic setting, while the portative organ speaks with delicate but spirited tone. The RP-1 treated each instrument with hallowed mercy. The Rogue's line stage tested high as heaven for purity, sanctity, and low distortion.

This vergeistigt Bach also tests a stereo system's ability to display the rhythms and musical structures pressed upon it. As I wound my way through these intoxicating preludes, I realized that the Rogue RP-1 was allowing me to better comprehend the relationship between Bach's inspired musical forms and his sincerely felt humanist expressions. I could not ask for more . . . or could I?

Listening with Headphones
The 8-ohm output impedance of the Rogue RP-1's headphone amplifier is a little high for my taste (footnote 1), so I used Grado Labs' new Limited Edition GH1 headphones ($650), a 32-ohm, open-backed design, to determine what effect this characteristic might have on slam, distortion, or frequency extension.

But wait! I need to interrupt this story for a testimonial: The most cost-effective tool for setting stylus rake angle (SRA) may be an ultraclear preamp phono stage (like the RP-1's) and a good headphone amp. When I listened again to Ravel's deep, complex concerto through the Grado GH1s, I instantly realized: the Hana EL's stylus was not sitting perfectly in the groove. Minute adjustments of SRA and vertical tracking angle (VTA) are easy with the Technics SL-1200GAE turntable: just rotate the large, calibrated tonearm base. Playing low-frequency piano attacks and passages of extreme high-frequency energy, I was able to zero in by using the Technics' height adjuster, changing my original setting of 1.8mm to 0.6mm—at which point the micro-spaces around high-frequency notes became more clear and noticeable. Groove noise diminished. The soundstage enlarged and, suddenly, the piano soundboard appeared.

Unfortunately, the Rogue drove the GH1s with a sort of muted clarity. Music was enjoyable enough, but the RP-1's headphone stage lacked the richness, sparkle, and dynamic impact of its overachieving phono and line stages.

AudioQuest's 25-ohm NightHawk ($598.75) and AKG's 36-ohm K812 ($1499) headphones reconfirmed my good work on the Hana's SRA, and those two of my favorite headphones confirmed the mostly average audio quality of the RP-1's headphone output.

In summary
I believe that Rogue Audio's RP-1 will join the ranks of such preamp folk heroes as the Dynaco PAS, the Hafler DH101, the Conrad-Johnson PV3, and the NAD 1020—and the Apt Holman, the Supraphon Revelation Basic, and the Audible Illusions Modulus. All of these are moderately priced, high-performance models that countless audiophiles have used to step up from receivers or integrateds to separates.

However, the RP-1 was more effective than any of those classics at preserving a recording's vital energies. I believe that the RP-1 is not necessarily a stepping stone on the way to something better: I see it as a fully worthy final destination.

Compared to any preamplifier I know of at anywhere near its price, the RP-1 reaches deeper into the music to excavate a stronger, more precise, more spacious musical presentation. Most important, it delivers music that lives. Highly recommended.

[long pause]

Wow! That was nice!

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Footnote 1: I like to see at least a 10:1 ratio between a headphone amplifier's output impedance and the headphones' mean impedance.