It strikes me that preamplifiers have always so dramatically varied in form -- by era, by manufacturer, by purpose -- that rarely has there been a preamp that one could describe as “typical.” Early on, the functions offered were amazing. Some early preamps provided different phono-equalization curves for the many different ways record labels equalized recordings; thank goodness, now all we have to worry about is RIAA. The famed McIntosh Laboratory stereo models of the 1950s through the 1970s featured a seven-position Mode switch that gave the user the choices not only of stereo, reverse stereo, and mono (L+R to both channels), but left or right channel individually to both outputs, or L+R mono to either the left- or right-channel outputs. The ubiquitous Dynaco PAS-3X, of which more than 25,000 were made, offered three mono modes (L, R, L+R) and full stereo, plus two levels of “blended” stereo that traded a loss of channel separation for a quieter signal.
Beginning in the 1970s, the “basic” preamp became the norm: just a power switch, volume control, input selector, and, perhaps, a balance control. The assumption was that nothing should inhibit the purity of the signal -- tone controls were anathema, and even balance controls were sometimes viewed with suspicion. The ideal was a “straight wire with gain.”
Today, most high-end preamps still lean toward the basic, including the subject of this review: Rogue Audio’s RP-1 ($1695 USD). But there’s nothing basic about its performance.
About Rogue
Rogue Audio -- a small company headquartered in Brodheadsville, Pennsylvania, near the Pocono Mountains -- has developed a strong following with its tubed and hybrid audio equipment. The RP-1, introduced toward the end of 2015, is the entry-level preamp in its extensive line.
Chief designer and company principal Mark O’Brien described his reason for starting Rogue -- a fairly common story in audio:
I started Rogue Audio 20 years ago as a result of losing confidence in what were the primary players in high-end audio at the time. As an audio consumer, I found that the equipment was getting really expensive, and in many cases, didn’t even sound very good. So I set about designing a bunch of preamps which eventually evolved into the Rogue Sixty-Six. I was working at Bell Labs at the time and convinced two colleagues (Mark Walker, a mechanical engineer, and Phil Koch, an industrial engineer) to join me in starting Rogue Audio. Our goal was, and still is, to design and produce affordable yet excellent audio equipment. I think the RP-1 is a perfect example of our retaining this core directive through the years. While we make much more expensive equipment, I believe every piece of gear we produce is still a great value in its particular category.
Description
The RP-1’s front panel -- a thick piece of aluminum available in black or silver -- exudes a build quality far above that of most entry-level gear. At either end are large aluminum knobs, each of which can be turned or pushed. The rotary motions control Balance (left knob) and Volume (right knob). Pushing the Balance knob toggles the two-line LCD display on and off; pushing Volume cycles through the RP-1’s phono and four line inputs. Below and just to the right of the Balance knob is the Power button; below and just to the left of the Volume knob is a 1/4” headphone jack. Once the RP-1 is in operating mode, it displays the input and volume level selected.
The rear panel is straightforward. About a third of the way from the left edge is a grounding screw for a turntable. Most of the rest of the panel is occupied by nine left-and-right pairs of RCA jacks. From left to right, these are: two variable and one fixed output, a phono input, four line-level inputs, and a unity-gain home-theater (HT) input. When the RP-1 is turned off, the HT input routes the A/V processor’s signal passively through the RP-1 to the power amp; if the RP-1 is turned on, the HT sends the signal as processed by the RP-1. At the far right of the rear panel is an IEC AC connector.
The RP-1 measures 15.25”W x 3.2”H x 14.5”D and weighs a solid 16 pounds. Other than the front panel, the case is of heavy-gauge steel in a black crackle finish. The interior is dominated by a sizable toroidal power transformer, the parts selection appears excellent, and the printed circuit boards are near works of art.
Included is a four-function remote control that duplicates the functions of the Volume, Balance, and Input controls, along with a switch that provides a function the front panel doesn’t: Mute. Having a remote is nice, but this one isn’t up to the exceptional standard of the RP-1 itself -- it’s very plasticky and looks a bit amateurish. Still, it did all that was asked of it, and did it well.
Among its many desirable traits, the RP-1 is a real treat for vinylphiles: it comes with a phono stage as standard equipment, and both input impedances and output gain can be optimized for a particular cartridge. Seven levels of resistance are available for moving-coil cartridges, from 30 ohms to 1k ohms, plus the usual 47k ohms for some MC and virtually all moving-magnet designs. The gain can be switched between 43dB for MM and 58dB for MC. The phono stage is active; as O’Brien told me, it “uses two stages of amplification and a completely passive RIAA equalization circuit. The amplification is done using ultra-low-noise op-amps with FET inputs. I’m sure you are well aware of the decades-old arguments between using discrete transistors vs. op-amp gain stages in a phono preamp, but at this point, the best op-amps are just as quiet as the very best discrete devices and they sound terrific. The ones we use are specifically designed for high-end audio applications and really work well.”
The RP-1 is a hybrid design: Its circuitry includes two 12AU7 or ECC802 tubes in the final output stage, in a mu-follower circuit. O’Brien explained: “I use a mu-follower in most of our tube preamp designs because it offers excellent specs and sonic performance. Really, much better than typical cathode followers and other popular circuit types. When designed properly, you get a usefully low output impedance, super low noise, low distortion and wide bandwidth. The mu-follower also has excellent power-supply noise rejection. Of course, you can achieve much of the same with solid-state designs, but I have never been able to recreate the ‘tube magic’ with solid-state circuitry (believe me, I’ve tried . . . ).”
The RP-1 is based on Rogue’s new RPX platform. This, O’Brien says, “is the hardware and software platform that is the basis for all new Rogue Audio preamps going forward. The software was all developed in-house and allows us to bring much more functionality to our new designs as well as adding features, such as the OLED display that we use on the RP-1. Our older preamps used a very simple controller that could only handle volume control and mute. The RP-1 has a much more sophisticated controller that can handle many more processing tasks.”
Rogue offers the original purchaser a three-year warranty on materials and workmanship and a six-month warranty on the tubes. If you have no local Rogue dealer and must order by mail, don’t worry: the RP-1 comes in sturdy protective packaging that should survive the delivery guy bouncing it off your front porch.
When the RP-1 is turned on, it displays a 30-second countdown before going into operation. This prevents any voltage anomalies from reaching the power amp and possibly damaging the speakers.
Setup
Everything about connecting the Rogue was straightforward, helped by its excellent owner’s manual. I connected my sources: Hewlett-Packard computer, HRT Music Streamer II+ DAC, Cambridge Audio 650C CD player, and Pioneer PL-516 turntable with Grado Gold cartridge. Interconnects were Linn Silver (CD player), Straight Wire Chorus (preamp to amp), and Dayton Audio (computer to DAC, USB; DAC to preamp, analog). The Rogue RP-1 fed my NAD C 275BEE power amp, which drove a pair of Acoustic Energy Radiance 3 floorstanding loudspeakers and an Advent ASW-1200 subwoofer.
Sound
Right out of the box, the RP-1 offered a very open, wide-ranging sound that seemed to only improve over the several days I broke it in with FM interstation noise, interrupted by a few listening sessions to check its progress.
After that burn-in phase, I began my preamp adventure with digital recordings. The bass in “Bali Run,” my old standby from Fourplay’s Fourplay (24-bit/96kHz FLAC, Warner Bros.), was deep and meaty, with good slam. The midrange was bright but not brittle, the highs extremely clean with no sense of overload. There was apparent space around the instruments, which were precisely placed. I can’t remember this track sounding this good before.
Next came another favorite: “I’m an Errand Boy for Rhythm,” from John Pizzarelli’s My Blue Heaven (24/96 FLAC, Chesky/HDtracks), which also featured excellent placement of instruments, and of Pizzarelli’s voice in his utterances during his guitar solo: his voice came from directly above and behind the guitar, as you’d expect it to. Also, the group sounded as if it was set up in the studio as it had been when I saw Pizzarelli in concert: piano far left, with the bass next, then Pizzarelli, and finally, the drum kit. Pizzarelli’s fabulous playing was reproduced as well as I could imagine it.
“Kapten Kapsyl” (Norwegian for “Captain Bottletop”) is on the 2L-TWBAS 2012 Sampler collection compiled several years ago by editor-in-chief Jeff Fritz (24/176.4 FLAC, 2L/SoundStageRecordings.com). Although the song is apparently the product of the Norwegian trio Väsen, this version is performed by violinist Emilia Amper and the Trondheim Soloists. Very lively, it starts off with Amper’s solo establishing the tune. Her nyckelharpa was well-nigh perfectly reproduced, with a gorgeously full, clear, precise sound that was well out in front of the orchestra. For their part, the Trondheimers sounded as if they were recorded in a huge space with lots of natural echo, which gave it a somewhat ethereal sound and a good sense of ensemble.
Another favorite, “Killer Joe,” from Quincy Jones’s Walking in Space (16/44.1 WAV, A&M), was fantastic. This late-1960s recording has exaggerated L/R separation of instruments with nothing in the middle, and the RP-1 accurately reproduced that dated sound. The flute solo was particularly tasty, with a little bit more air to the flute’s sound than I’m used to hearing. The muted trumpet solo, as well, shone, with precise attacks and releases.
Next was a remastered Frank Sinatra recording, “Wave,” from Ultimate Sinatra: The Centennial Collection (24/96 AIFF, Reprise). This is one of his later recordings, when the voice was not so much “The Voice.” It’s a bit ragged, but the man knew how to sell a tune. The recording is outstanding, with incredible detail -- you can hear his quick breaths (how he smoked two packs of Kents a day and could still hold a note for goodness knows how many measures is beyond me). My notes: “Fabulous! Great! Exceptional!” All that.
I then cued up “The Circle Game,” from Joni Mitchell’s Ladies of the Canyon (16/44.1 AIFF, Reprise). Her voice can sound really brittle, but here it sounded almost sweet. The 12-string guitar was gorgeous, with incredible detail. In the verses, when Mitchell sings solo, her voice hovered in the ether. It’s the best I’ve ever heard her sound.
“The Game of Love,” from Santana’s Shaman, features singer Michelle Branch; it was a major hit in 2002, and I’ve loved it ever since. Recently I came across a CD of the international version of Branch’s second album, Hotel Paper (16/44.1 WAV, Maverick), which includes this track. The WAV file sounded dense, perfect for hit radio. Santana’s guitar cuts through the general hoo-hah going on in the background, including Branch’s voice on occasion. There’s a whole lot goin’ on in this recording, but the RP-1 reproduced all of it, in detail and with great depth.
As noted above, Rogue included a phono stage in the RP-1, and I was anxious to check it out. It was a revelation! The Rogue RP-1 had the quietest phono section I’ve ever heard. Even with the preamp cranked up with no signal, there was virtually no hiss or hum from my speakers.
First I played “You Can Call Me Al,” from Paul Simon’s Graceland (LP, Warner Bros.), on my Pioneer PL-516 with Grado Gold cartridge -- a combination that, as I’ve noted before, sounds quite smooth. However, the result was not appealing: far, far too mellow, distant, and uninspiring. There was no rhythm apparent in the performance. So I switched over to my newly restored Dual CS-5000 with Shure M97Xe cartridge.
That was the ticket. Through the Dual-Shure, I was amazed at the great soundstage depth. Also, there was much more extension at both the top and bottom of the audioband. The bass and percussion were solid, with lots of punch and slam. Soundstage width and depth were what I expected, if not more. This was definitely an “analog” sound: the highs were far less etched than they would be from a digital source’s playback of this recording. But I wasn’t disappointed -- I don’t expect an LP to sound as crisp as digital. The flute solo’s sound was perfect. There’s a spoken “Hallelujah!” near the end that I’d never noticed before, either on LP or CD. Also, the bass run at the end of the track provided a lot of detail that I don’t always hear on an LP.
Turning to Simon’s erstwhile singing partner, I played “Finally Found a Reason,” my favorite cut from Art Garfunkel’s Fate for Breakfast, from 1979 (LP, CBS). It’s a brighter recording than Graceland, and that’s perfect for Garfunkel’s voice. Amazingly, in light of that, what struck me first was the bass presence, especially that of the insistent kick drum; I hadn’t noticed that before through my own preamp. Another impression was that the guitar and voices were reproduced with the delicacy that this recording deserves. All in all, the RP-1 reproduced this track just about perfectly.
A longtime favorite of mine is Mad Romance, a long-gone, DC-area quartet from the 1980s: two men, two women, singing jazz versions of selections from the Great American Songbook. You could almost call them DC Transfer -- their arrangements were similar to those of Manhattan Transfer. This time I chose “Taking a Chance on Love,” from Mad Romance (1987 LP, Zanzibar), and the sound was better than I’d heard it before. There was an incredible blend of sounds, as you’d expect, but with enough individual detail that I could easily concentrate on each voice. The recording had great depth through the Rogue -- the four singers were well out in front of the instrumentalists, as they should be. I enjoyed this greatly.
So the RP-1’s phono section could strut its stuff with jazz, standards, and pop. How would it do with an LP of a heavyweight classical work?
The piece was the final movement of Saint-Saëns’s Symphony No.3, “Organ,” performed by organist Michael Murray and Eugene Ormandy conducting the Philadelphia Orchestra (16/44.1 FLAC, Telarc). This recording was made in the Church of St. Francis de Sales in Philadelphia, which has a magnificent organ. There was an incredible sense of air around orchestra and organ -- the sanctuary must be quite large and fairly live. There were layer on layer of orchestra from front to back, and the individual sections were quite discernible. When the organ came in full bore, it rocked my listening room, rattling the room and my fillings. This was definitely a case of settling back and enjoying the fact that my listening chair is probably much more comfortable than the pews of St. Francis de Sales.
For those of you unfamiliar with the “Organ” Symphony: If you want to test your system’s bass response, the final, swelling chord of the organ includes a 32’ pipe that puts out a low C at 16Hz -- a tone you can’t hear so much as feel, assuming your system can reproduce it. Mine can’t quite -- I get the 32Hz second harmonic of the C an octave above note -- but it’s still pretty stirring!
Although I spent hours and hours playing LP after LP, I’ll mention just one more cut: “Nunca Mais,” from the late guitarist Emily Remler’s Transitions (LP, Concord Jazz). It begins in the lower register of Remler’s insistent, percussive, hollow-body electric; after a while John D’earth’s solo trumpet enters, with the rhythm section. What I found interesting was that, through the RP-1, the trumpet’s sound was more prominent than that of the guitar and rhythm, without overpowering them. Remler’s guitar in her solo offered beautiful detail, but at the same time was mellow -- like one of her heroes, Wes Montgomery, she never used picks. A great way to end my listening.
Comparison
Immediate A/B comparisons between the Rogue RP-1 and my Linn Majik 1-P weren’t possible -- I had to disconnect the source and output from one preamp and connect them to the other. However, I can offer some impressions of the differences I heard.
I’ve had the Linn for 20 years now. When it replaced my McIntosh C27, it was for the Linn’s detail and wide bandwidth. I still admire the 1-P for those characteristics. But the Rogue RP-1 was better.
It’s my opinion that a phono stage is the ultimate test of the quality of what an audio company can do. I directly compared the two preamps’ phono sections, switching back and forth as I listened to all sorts of LPs and 45s. I think the most revealing recording was Garfunkel’s of “Finally Found a Reason.” Both preamps did commendable jobs of reproducing the tune, but the RP-1 excelled in the more nuanced aspects, providing that extra touch of detail in the highs and slightly deeper bass. Both midranges were fine, but I kept hearing just a bit more detail from the RP-1. The combination of a fine line stage and exceptional phono stage are the hallmarks of the RP-1.
I heard only minimal -- and no disqualifying -- differences between line-level sources through the Linn and Rogue. The 1-P’s midrange was perhaps more liquid than the RP-1’s, but both gave me most satisfying listening experiences, even as the RP-1 provided slightly more low- and high-end extension.
Conclusion
After intensive listening over an extended period, I can unequivocally say that Rogue Audio’s RP-1 is the best preamplifier I’ve ever reviewed. Its phono stage is to die for -- it may be the one I’ve lusted for all my life! The RP-1 offers four line-level inputs for additional sources that don’t seem to color the sound at all. It mated with my NAD power amp exceptionally well. It has incredibly solid bass output, a sweet and singing midrange, and crystalline highs. I imagine it might wash your clothes and make your coffee in the morning, if you asked it nicely.
When the Linn Majik 1-P came my way in 1996, it was an ear-opener. It’s still quite good, and will continue to be my reference. But as my 1977 McIntosh was surpassed in sound quality by the ’96 Linn, so the Linn is surpassed by this Rogue RP-1.
Rogue’s products aren’t found on every street corner -- they’re elusive beasts, but worth hunting down. For the money, I think there’s no better preamplifier on the market than the Rogue Audio RP-1.
. . . Thom Moon
thom@soundstagenetwork.com
Associated Equipment
- Turntables -- Dual CS5000 with Shure M97Xe cartridge, Pioneer PL-516 with Grado Gold cartridge
- Computer -- Hewlett-Packard Elite 6000 desktop with 3.0GHz Core 2 Duo CPU, 4GB RAM, 160GB internal hard drive running Windows 10 and JRiver Media Center 19; 2TB Western Digital external hard drive
- Digital sources -- Cambridge Audio 650C CD player, HRT Technology Music Streamer II+ DAC
- Preamplifier -- Linn Majik 1-P
- Power amplifier -- NAD C 275BEE
- Speakers -- Acoustic Energy Radiance, Advent ASW-1200 subwoofer
- Digital interconnects -- Dayton Audio USB
- Analog interconnects -- Dayton Audio, Linn Silver, Straight Wire Chorus
- Speaker cables -- Acoustic Research 14-gauge
Rogue Audio RP-1 Preamplifier
Price: $1695 USD.
Warranty (nontransferable): Three years parts and labor; six months, tubes.
Rogue Audio
3 Marian Lane
PO Box 1076
Brodheadsville, PA 18322
Phone: (570) 992-9901
E-mail: info@rogueaudio.com
Website: www.rogueaudio.com
