Integrated Amp Reviews

I wish you could have heard how physically present and emotionally intimate the Rogers 65V-1 made Buddy Holly's Down the Line: Rarities (2 CDs, Decca B0011675-02) feel through the DeVore Orangutan O/93s. The sense of Holly's physical presence was so captivating that I fell into a Holly listening binge that has yet to end. I'm infatuated with his famous Apartment Tapes, recorded in December 1958 in the living room of the Manhattan flat he shared with his new wife, Mar°a Elena Santiago, only weeks before his death at the age of 22.

I didn't need golden ears or laboratory meters to recognize that these recordings were being reproduced with unusual insight. Holly's acoustic guitar, his singing and speaking voice; Mar°a Elena's laughing, talking, and chatting on the phone—it all sounded so hauntingly real that I kept playing these tracks over and over. These home recordings, made on an Ampex R2R deck, delivered the type of intimacy I seek from a quality hi-fi. I could easily tell that Holly was sitting on his couch, his back to a window and an acoustic guitar on his lap. I could tell that he was recording into a single microphone on a short stand perched on the coffee table in front of him. In one track, as Mar°a Elena speaks to Holly from across the room, you can hear the Fifth Avenue traffic outside. Holly laughs a stoned laugh, then Mar°a Elena seems to pick up the mike, giggle mockingly, and loudly count to 10 in Spanish. The DeVore speakers and Rogers amplifier (EL34s in triode) made every tape-hiss–filled second monumentally human—like real art!

The Rogers 65V-1 let the vivid, undoctored reality of these tapes come through with eerie, preternatural directness. The last song on this set—"Smokey Joe's Café," a Leiber and Stoller masterpiece—was recorded only days before Holly's death. He plays an electric guitar, and every time the song ends, I sit there staring blankly into space, contemplating his genius, and what my Facebook friend meant by "an intimacy with music like no other."

Comparisons
Still using the DeVore O/93s, I swapped out the Rogers 65V-1 for another tubed, single-ended integrated amp, the Line Magnetic LM-518 IA ($4400)—except that the 77-lb (!) LM-518 uses directly heated 845 triode tubes and puts out 22Wpc, and its power supply is tube-rectified and choke-filtered. Through the LM-518, music seemed stronger, more whole, continuous, and vividly alive. Bass attack and decay, which are not the LM-518's specialties, were better defined. The treble was less extended than with the 65V-1, but more refined. Most important, the LM-518 put musical energy into my room with greater locomotive force that I believe was not simply the result of more watts, but of the Line Magnetic's lower output impedance—1.1 ohms, vs the Rogers's 8.5 ohms—and more substantial power and output transformers. The LM-518's heavy iron seemed to generate less hesitancy, lower distortion, greater ease of rhythmic flow, and enhanced corporeality.

The Rogers's EL34s beat the Line Magnetic's 845s in vocal tone and instrumental textures. In Ultralinear and triode modes, the 65V-1 had an uncanny ability to present instruments and voices in vivid textural relief. In my world, proper tone and highly tactile instrumental textures are major virtues.

Paired with the Zu Audio Soul Supremes
To try the Rogers 65V-1 in a versatile, moderately priced system, I used it with HoloAudio's Spring "Kitsuné Tuned Edition" Level 3 DAC ($2499), connected to my stoop-sale Integra DPS-7.2 DVD player used as a CD transport with Kimber Kable's D60 Data Flex Studio coaxial digital cable ($234.5/0.5m), and to the Rogers with Triode Wire Labs' Spirit interconnects ($349/m). The 65V-1, with EL34 tubes in triode mode, was tethered to the Zu Audio Soul Supreme speakers ($4500/pair) with 5' leads of Triode Wire Labs' American speaker cables ($699).

The primary effect of this rig was arguably some of the most lifelike reproduction of voices I can remember hearing. Proper reproduction of the human voice is not subtle. It is extremely rare when a reproduced voice sounds anything like a real voice. With the above-mentioned Buddy Holly CD and the Alan Lomax Collection's Southern Journey, Volume 2: Ballads and Breakdowns—Songs from the Southern Mountains (CD, Rounder Select 1702), the musical content and the quality of its reproduction held my attention with unusually high levels of I-was-there tonal and spatial realism. Not only did voices sound extraordinarily lifelike, the singers' articulation of words was extra-intelligible.

Surprisingly, the EL34-triode Rogers-Zu partnership delivered Music of Edgard Varèse, with Robert Craft conducting woodwinds, brass, and percussion ("six-eye" LP, Columbia Masterworks MS 6146) with LOUD deep bass and high-impact fidelity. In fact, the playing of this recording was one of the finest of my many fine moments with the 65V-1. Instrumental tone was a few clicks cooler than neutral, but textures seemed unusually intense.

The Rogers drove the Soul Supremes with unprecedented three-dimensionality. Bass was less deep, weighty, and well-drawn than it is with my First Watt J2 amp. But seldom have the Zus sounded so microdetailed or coherent. This surprisingly revealing system flowed easily, diving deep into these seductive Varèse compositions. By the end of side 2, I was drenched in music and totally spent.

Ultralinear vs Triode
First realized in 1937, by audio god Alan Blumlein (1903–1942), Ultralinear operation yields somewhat reduced amounts of each of the aforementioned pentode-triode characteristics. Ultralinear mode is typically well sorted, unobtrusive, competent at everything, never great at anything.

Although I might describe the audio character of pure pentodes as a little peaky-pointy, I like that mode of operation—because it delivers a tube's full gain and power. Best of all, it pure pentode operation showcases instrumental textures in spiderweb-filigree ways. The character of pure pentode transparency is dark, deep, emphatically detailed, and highly viscous. Pianos sound especially tangible with pentodes: linear and Apollonian.

Triode-wired pentodes make bass with softer edges, and sound that's slightly congested or diffuse. Textures are less bas-relief than with a pure pentode. But triode wiring offsets these deficiencies by adding an intoxicatingly color-saturated tonality. Aural images on triode soundstages seem more physical, more brightly illuminated: painterly and Dionysian.

Switching between the Rogers 65V-1's triode and Ultralinear modes yielded results exactly like those just described. With the low-sensitivity Falcon LS3/5a's, I preferred the extra bite, punch, and muscle of Ultralinear. The Zu Soul Supremes and DeVore Orangutan O/93s were both sensitive enough to let me relax, focus on the recording, never obsess about clipping, and luxuriate in the delicacy, intimacy, and more saturated colors of triode-wired pentode sound.

Driving Headphones
The 65V-1's headphone output had the same basic sound character as its speaker output—but I can't say it yielded dead-quiet, ink-black spaces, especially with such low-sensitivity headphones as the HiFiMan Susvaras, with their impedance of 60 ohms and their sensitivity of 83dB/mW/kHz. The Rogers drove the HiFiMans to only moderate levels, and with a slight, hard dullness to the sound.

The 65V-1's headphone amp achieved its most neutral, voice-articulate, soundstage-revealing best with the more sensitive Focal Utopias (80 ohms, 104dB/mW/kHz). With the title track of the Alan Lomax Collection's Southern Journey, Volume 6: Sheep, Sheep, Don'tcha Know the Road—Southern Music, Sacred and Sinful (CD, Rounder Select 1706), sung by Bessie Jones and the Sea Island Singers, a single person is clapping his or her hands about 20" from the mike; I swear, with the 65V-1, I could hear each compression of the palms' flesh squeezing out air. The room was more accurately described, if less colorfully presented, than with any of my other headphone amps.

Unfortunately, the joys of this extraordinary resolution were limited. Overall, the 65V-1's headphone sound seemed not like sweet-glowing, triode-wired, single-ended EL34s, but slightly dulled and hard—more like solid-state with too much feedback.

Conclusions
I listened to the 65V-1 with both the Mullard EL34 and Gold Lion KT88 tubes. The KT88s delivered a bigger fist and a stronger blow—their detail was more etched. But my most pleasurable experiences—the ones I write about here—were with EL34s.

About 1989, I was powering a variety of highly sensitive loudspeakers with a 2W, push-pull, mono amplifier designed and built by Ken Shindo, of Shindo Laboratory; its single output tube was a 10Y/VT25 directly heated triode. Its output was so low that I couldn't stop obsessing: Is this enough power? I constantly cocked an ear, listening for clipping distortion. Nevertheless, while driving a fresh pair of Altec Lansing 604B full-range drivers fitted to very large enclosures (footnote 1), I experienced unprecedented levels of vividness of vocal tone and instrumental texture—something that, ever since, I've sought but never found. I believe the Rogers High Fidelity 65V-1 integrated amplifier, driving the Zu Audio Soul Supremes, may have come close to my memories of that incredible combination of Shindo amp and Altec speaker. I also believe that some part of the Rogers-Zu combo's rich tones and vivid textures may be a consequence of the 65V-1's high output impedance. But I don't care. The effect is emotionally engaging.

The 65V-1 is a charming, satisfying amplifier that, to reveal anything near its full potential, needs to be paired with extra-sensitive (ie, greater than 92dB/W/m) speakers whose average impedance exceeds 8 ohms. Matched to a pair of such speakers (models from Audio Note, Avantgarde, DeVore, Klipsch, Tekton, Volti, Voxativ, and Zu come quickly to mind), the Rogers 65V-1 should exhibit most of those traits my Facebook friends ascribed to single-ended amplifiers, and especially: intimacy with the music, incomparable midrange texture, and eerie, preternatural tonality.

Rogers High Fidelity's 65V-1 is an uncommon audio product in search of uncommon audiophiles. Might you be one of them?

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Footnote 1: Altec's literature described the 604B as "The most efficient all-range speaker unit ever built."