Rogue Audio RH-5 preamplifier-headphone amplifier

Every day in my bunker, I use one of a few high-quality headphone amplifiers to double as a line-level preamplifier-controller and operate as the quality-assurance reference for my ongoing audio experiments. I must choose this component carefully, because it determines the upper limit of my system's ability to reveal any subtle differences among components under review.

A mediocre line stage will bring my system down: it will harden, cloud, or dull the music, making it sound canned. A superior line stage will raise my system up, allowing recordings to display their raw textures, natural colors, and subtle dynamic expressions. A superior line stage always sounds lively and transparent.

"Music grew like a grapevine that was never pruned."
I had listened only to Appalachian folksinger Neil Morris's "Turnip Greens" and "Music Has No End" (with commentary), from the Alan Lomax anthology Southern Journey, Volume 7—Ozark Frontier: Ballads and Old-Timey Music from Arkansas (CD, Rounder 1707), before I realized that Rogue Audio's new RH-5 headphone amplifier possessed the resolution, forcefulness, and transparency of a superior line stage. That pleased me, because the RH-5 has four (!) selectable line-level inputs. My reference headphone amp, a Pass Labs HPA-1, has but two. And the RH-5 put out some real power. I smiled and wondered: Could this preamp and headphone amp effectively anchor the center of my reviewing practice? I hoped that it could, because I need more source inputs, and a bit more torque for hard-to-drive headphones. But reason prevailed: No, probably not. It's too much to ask of a component costing only $2495.

Description
Rogue Audio's RH-5 is a headphone amplifier and line-level preamplifier whose hybrid circuitry includes MOSFET transistors and two 12AU7 tubes (ECC82s can also be used). It has an output impedance of <0.1 ohm at 1kHz, and outputs 3.5Wpc into 32 ohms. The RH-5 measures 15" wide by 4" high by 13.5" deep and weighs 19 lbs.

Its black steel case is fronted by an elegant faceplate of anodized aluminum. At far left are two studio-grade headphone jacks, each combining a ¼" phone jack and a three-pin XLR jack. To their right is a four-pin, balanced XLR jack. The RH-5 permits the simultaneous use of two pairs of headphones.

At the faceplate's center is Rogue's signature oval display. Its blue characters indicate the volume level, which input is connected, and which of the three gain settings (or Mute) has been selected. To the right of the display are small buttons for Select, Mute, and Gain, followed by a large Volume/Display knob of 185 detents, and then a small Power button. All controls are duplicated on a flimsy plastic remote-control handset.

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On the rear panel, starting at far left, are: a ground post for a turntable, followed by three single-ended stereo inputs (RCA), labeled Line 1, Line 2, and Line 3. Next is a stereo Pre Out (RCA), followed by balanced stereo input and output (XLR), then the IEC power inlet and main Power rocker switch. At the center of the rear panel, running along its bottom edge, are the words "MADE IN THE U.S.A." The RH-5 is warranted for three years, its tubes for six months.

The RH-5 has no DAC. I like it like that. My own DACs—Schiit Audio's Yggdrasil ($2299), and Mytek HiFi's Brooklyn ($1995) and Manhattan II ($5995)—please me well enough. The review sample of the RH-5 came with Rogue's optional moving-magnet/moving-coil phono-stage ($400). I wish it hadn't. I'm a student of fine phono stages, but the RH-5's phono board occupies the first of its three RCA inputs. This might have been a problem, because I need to connect two turntables (and their attendant phono stages) and a DAC. Fortunately, my Parasound Halo JC 3+ phono stage ($2995) has a balanced XLR output, so I was able to connect it to the RH-5's XLR input. I connected a Tavish Design Adagio phono stage ($1690) to one of the line-level RCA inputs and the Mytek Manhattan II to another.

Line-Stage Breakdowns
The late Bill Monroe, founder and CEO of bluegrass music, described his genre as "Scottish bagpipes and ole-time fiddlin'. It's Methodist and Holiness and Baptist. It's blues and jazz, and it has a high lonesome sound."

I hear bluegrass as dance-paced plucking, calling, sawing, and strumming that beats along at the same high rate as my Midwestern heart. In "White House Blues," from the anthology Classic Bluegrass from Smithsonian Folkways (CD, Smithsonian Folkways SFW CD 40092), Earl Taylor and the Stony Mountain Boys do irony and black humor at runaway-train speed: "Roosevelt's in the White House, he's doing his best / McKinley's in the graveyard, he's taking his rest." The Rogue RH-5 helped direct my attention to the hypnotic clarity of the varying empty spaces, short but always pregnant, between Taylor's picked banjo notes. The RH-5 made every note sound tonally unique. It helped "White House Blues" show why, in 1959, Taylor and the Stony Mountain Boys became the first bluegrass band to play Carnegie Hall.

Taylor fondly remembered his big night at Carnegie: "When we would end a number, I knew that it would take five minutes before we could go into another one—that was how much rarin' and screamin' and hair-pullin' there was." My Mytek Manhattan II DAC, First Watt J2 power amp, and DeVore Fidelity Orangutan O/93 speakers combined with the Rogue RH-5 to let Earl and the Boys show me why those New York swells were rarin' and screamin'. Imagine certified organic tone, well-described note bursts, and furious foot-tapping momentum.

I missed the 1930s, but in the 1990s, someone told me that morphine cures pain so well it makes your body feel as if it's rising up off the couch. "It better," I joked. "Because listening to Morphine makes my body sink down into the couch."

Since then I'd forgotten both drug and band—until Sphere gave me a copy of Morphine's At Your Service (2 CDs, Ryko/Rhino 520603), released 10 years after Morphine's frontman, slide bassist, lyricist, and lead singer, Mark Sandman, died onstage in 1999. Comprising only previously unreleased recordings, At Your Service shows the listener a darker, more downbeat version of the band than more famous studio albums such as Yes and Cure for Pain. If you've never experienced this band, imagine Sandman's fingers plucking long, slow note-codes from his two bass strings (sometimes he added a third, regular guitar string). He explained, "Each string holds every note—so two strings is not a limitation." Add Dana Colley playing baritone saxophone and their combined deep voices, and the result is a strange, artful river of pure baritone sound. Three nights in a row, I nearly drowned in this mesmerizing river—and for that I blame the Rogue RH-5's ability to submerge me in its every undercurrent and textured nuance.

The RH-5 preamp loved Sandman's voice and bottleneck bass. It made Colley's sax growl, drone, and tangibly expand into a field of copious reverb—especially when connected to the First Watt J2 driving the Zu Audio Soul Supreme speakers. It sorted out the bass, drum, and saxophone parts better than the PrimaLuna ProLogue Premium preamp or Pass Labs HPA-1 preamplifier-headphone amplifier did. Musical weight, body, and expression were delivered, with zero robotic hi-fi-isms. Sandman's bass shook my bunker floor, and Colley's sax scratched wildly at my chest. Billy Conway's drum inventions were a dream to follow.

Morphine sounds best loud. The RH-5 brought so much clarity and so little distortion to the First Watt–Zu combo that, as one track led to another, I just kept turning it up—not because it sounded dull (it didn't), but because the weight and texture of At Your Service kept sinking me deeper into my couch. I kept imagining Mark Sandman just above me onstage. There was bass everywhere.

As a line-level preamplifier, the Rogue RH-5's most noble traits were its ability to convey the weight and force of music, and the splendid transparency of its two 12AU7 tubes.

Listening: Headphone haute
Sphere and I have been simultaneously experimenting with Rogue's first foray into headphone amp design. We kept our results to ourselves until, one day at lunch, Sphere blurted out, "This new Rogue makes more of my headphones sound great than any other amp I have!"

I remained silent.

To get readings on its sound character and load-driving abilities, I listened to the Rogue RH-5 through three esteemed headphone models: Sony's MDR-Z1R, HiFiMan's HE-1000 V2, and JPS Labs' Abyss AB-1266 Phi.

COMPANY INFO
Rogue Audio, Inc.
PO Box 1076
Brodheadsville, PA 18322
(570) 992-9901
ARTICLE CONTENTS

COMMENTS
georgehifi's picture

Not really.
That the output coupling cap is way too small, no bass into any amp that has low input impedance. EG: some Pass and others and many Class-d amps are 10kohm input, and this preamp will roll off the bass with phase shifts early into these.
Unforgivable, that cap should be at least 4 x larger for a pre that cost this much.

Cheers George

John Atkinson's picture
georgehifi wrote:
That the output coupling cap is way too small, no bass into any amp that has low input impedance.

Power amplifiers with an input impedance below 1k ohms are very rare. (Only some, the Jeff Rowland models come to mind.) The Rogue preamplifier will not have a noticeably rolled-off bass if the amplifier's input impedance is 30k ohms or higher.

John Atkinson
Editor, Stereophile

georgehifi's picture

Looking at the measured graph, it's already -3db at 250hz!! into 600ohms.
For optimal performance (no rolloff or phase shift) this pre should state that it need to see/drive amps with at least 33kohm or higher input impedance. otherwise there'd be many disappointed buyers.

Cheers George

mrkaic's picture

"otherwise there'd be many disappointed buyers."

Subjectivists might like this frequency response if told by a high enough authority that the device sounds "artisanal" or something similarly uplifting.

mrkaic's picture

...that this thing is reviewed next to DAC3?

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