Review of Rogue Audio RP-9 preamp
I recently upgraded my RP-7 to the RP -9. Before doing so, I found very few reviews on the RP-9 and hence would like to offer the following that might perhaps be useful to anyone considering the RP-9.
For purposes of this review of the Rogue Audio RP-9 preamp, consider two analogies: (1) a circle to be “filled in” and (2) the night sky.
You could use the side of a pencil “lead” and shade in the circle. Depending on the pressure you assert, the shading would be darker or lighter, but regardless, it is smooth, uniformly filling the circle. This would equate to a full, rich tone, but lacking in detail and spatial “clues”. It is equivalent of the back row of the balcony, where by the time the sound of an orchestra reaches your seat, it is well blended, homogenized. You hear the summation of all the musicians but cannot readily hear the individual components that create the composition.
Alternatively, you could use the tip (point) of the pencil and make “dots” or points within the circle. If you create a sufficient number of dots, the circle will appear “filled in” when viewed from a distance, yet upon closer inspection, the individual dots are apparent. (In art, this is called pointillism and was used by Georges Seurat and Paul Signac.) The technique allows for both a detailed and a cohesive presentation. It presents music as if heard from the seats in the “golden circle” of the concert hall or the first few rows of a concert venue. The relative pressure applied to the dots (darker or lighter) or the size of the dots, can convey spatial information and/or highlight individual musicians or components of the composition. Note that the number/size of the dots is important: few but large dots may sound very articulate, but lack the cohesiveness to present the composition “musically.” Conversely, too many small dots might sound merely homogenized.
The RP-9 fills the circle with dots, but Mark O’brien, who designed the RP-9, has been able to choose just the correct number and size of dots such that music is presented cohesively and richly, yet with detail and articulation. The fullness allows you to “relax and enjoy the music”; the articulation and wide/deep soundstage permits the listener to appreciate the detail or construction of the composition and the artistry of individuals musicians. This is the case whether listening to classical, small ensemble or “big band” jazz, or singers.
The dots are not as sharp and pointed as the previous description might imply. There is subtle shading of the dots. Thus the articulation is accomplished withOUT clipping either the leading or trailing edge of the notes. The exquisite delicacy and nuance of the “shading” of the dots allows the RP-9 to present the timbre of instruments (and voices) accurately. The listener can appreciate the talent of the musician and to hear the subtle differences, for example, in bowing, piccata “fingering”, the bounce of the bow or the twang of the guitar. The different armatures used to create the varying sounds of a sax, or the breath and “tonguing” of a trumpeter producing edginess vs mellowness of a trumpet, are clearly discernible. I hasten to add, that such “detail” is never distracting but rather an integral part of the presentation that enhances the musicality.
The character of the venue is easily perceived with a presentation that places you in the “golden” seats of the concert hall or in the middle of the crowd at an “open” venue. For example, notes may linger in reflection from the walls of a church. The musicians are accurately placed on stage and the depth of the soundstage adds to the realism of a concert hall. The width of the soundstage easily extends beyond the speakers laterally when so mastered. Recordings from the studio bring the musicians into your listening space, live before you so realistically you could shake hands or turn the page of music.
Unless you purposely, analytically, dissect the presentation, the detail, articulation, etc. are as in a pointillism painting, unnoticeable; rather the RP9 is so cohesive, the sound so integrated, so engaging, that you hear (perceive) only music. Close your eyes, and every other thought dissipates.
We know that if we look at the sky during the night we should see literally millions of stars, pinpoints of light exuding from absolute blackness. Indeed, during a trip to Africa, I was struck by the shear number of stars that give the illusion of “milkiness” from which out galaxy derives its name. Yet, upon inspection, the individual stars, pinpoints of light, could be discern. Thus, I could simultaneously appreciate both the detail and the grandeur of the heavens.
Yet, for most of us living within cities or suburbs, we seldom see but a fraction of these stars, just a few particularly bright ones that are intense enough to penetrate through the veil of the light “pollution” that emanates from our cities and suburbs.
The RP-9 is devoid of “light pollution”, its sky is solidly, deeply black, and hence the music has clarity and articulation, there is marked dynamics, for the softest of passages can be heard without strain. Complex orchestral pieces are not muddy, muffled, confused, blurred, even in the fastest of passages full of glisses, scale runs, trills, etc. Fortissimo climaxes are not merely loud; the components of the “loudness” are still discernible. Yet, this detail while clearly appreciated, is presented with such coherence that it becomes subliminal; it is there if you want to listen analytically, and its not if you are engaged in the total musical presentation.
As always, the quality of the source is crucial and the RP9 cannot magically transform a poorly recorded or mastered album. But, even a compressed, poorly mixed track will sound better. But given good recording and engineering, the RP-9 is so engaging you are engulfed in the music.
When I was considering upgrading from the RP7 to the RP9 I asked Mark O’Brien what was the difference. With regard to the treble, he merely said the RP9 was “airy.” I am not sure I would so describe his accomplishment, for it is not al all thin or wispy or ethereal. Rather, the notes are as solid as the mid and bass, clear, distinct, with a purity of tone and preservation of the timbre of the instrument. Delicate, at times, and never harsh, biting, stinging, but still authoritative when called to be. The RP9 will challenge your speakers’ frequency range for it is able to produce notes far below 20 Hz and far above 40Hz. On Beethovens Organ Concerto, after the fortissimo opening chords, there is a passage where the smallest of pipes produce tones at the limits of an adult’s hearing. With the RP7 I would strain to hear these notes, sometimes wondering if I imagined them or missed them entirely. With the RP9 they are clear penetrating the air far to the right of the speaker. And, while referring to organs, the pedal notes are authoritative, full, intense, limited only by my speakers’ 28Hz limit. Pedal note based chords are not merely thunderous, homogenized “loudness”. Rather, the notes of the chord are in suspension, individual yet cohesive. The tonal character of the various stops can be appreciated, e.g. reeds vs brass.
Returning to the original analogy, bass is a circle filled with many dark dots, full yet distinct. The circle is “big” when called for. The bassist’s technique is evident. Tympani are resonant and have tonal timbre, character. In general, the bass is not merely a rumble in the background obscuring the midrange or treble. It is supportive, a foundation, solid but distinct, individual pillars not merely a pile of sand or a slab of concrete.
The midrange is neither emphasized nor submissive. It is not forward or prominent, it is just part of a continuum balanced per the recording. As with bass and treble, instruments within the midrange are presented with proper timbre and “impact”. If we return once more to our analogy consider shading the circle with color. If we use both red and blue we see purple, use yellow and blue and we see green, once mixed, we do not see the original colors, but the resultant. In terms of bass, midrange and treble, the RP9 mixes these in just the right amounts to color the circle artistically. (The analogy is not perfect in that if we purposely listen analytically, we can dissect the bass, mid and treble and listen to each, they are not blended to the point of not being able to be separated as they would be with pigments.)
The treble is not harsh, bright, biting or stringent. At least with my Sonus Faber Amati Tradition speakers, the timbre and tonal character of the treble instruments are accurate. This is true for both string instruments (eg violin) and brass (consider the piccolo vs regular trumpets in Canadian Brass’ LPs). For example, Hovhaness often sprinkles an approximately 6 note “run” of either a harp or a glockenspiel, “on top of” a full section of strings and even brass in each of his symphonies. (I note that he uses this “pixie dust” almost as a signature similar to Dali’s clock.) The RP9 lifts these notes above the fray and allows them to be readily heard and appreciated. (I want to use the adjective “sparkle” but do not want to convey the sound as too brilliant or bright; they are sprinkled onto the orchestration floating in a character somewhere between glitter graffiti and snowflakes.) When listening “live”, I note that the very upper most keys of the piano often have a nearly flat, tinkle tone less “resonant” or complete than midrange or the lower octaves. Similarly, the pedals add a character to a note (especially mid octave or bass). The RP9 produces such subtleties clearly and precisely whether the music is jazz or classical. I suspect this contributes to the illusion of a “live concert” or being in the small jazz cafe.
A final note regarding the overall “sound” of the RP9. Like the rest of the Rogue Audio line, while it is tube based (Russian 6H30P) it does not have the syrupy, excessively warm sound often associated with tube preamps and amps. Rather, its sound could best be described as a solid state that has been to finishing school and acquired refinement and couth.
Unlike some manufacturers that feel obligated to dress their equipment in fancy, elaborate cases, Rogue chooses to be distinctly “understated.” Their effort is entirely in the electronics, not the case (although, the remote is quite nice). This is not to imply that the Rogue is a diamond in the ruff; it has been exquisitely cut and polished. It is simply not dressed in a tux, but prefers casual attire. It is the comfort provided by a close friend rather than the politeness of an acquaintance. I high recommend that you “get to know” the RP9.
AMG Viella turntable with the JT12 arm and SoundSmith strain gauge cartridge
dCS Rossini DAC
Rogue Audio Apollo Dark monoblock amps
Sonus Faber Amati Tradition speakers
Nordost Valhalla 2 cables
Puritan 156 AC conditioner
20A dedicated circuit
Great write-up, craig. When I was looking at preamps I really liked the RP-7 and would have bought it had it not been for older versions having no RCA to balanced HT pass-through (it was a store demo I was buying). The RP-9 came out around the time or just after and unfortunately never got to hear it. I bet it's great. Thanks for your time and effort. I'll hear one someday.
@gakerty please report when you have auditioned RP9 upgrade. I too use the Legacy Signature SEs (with a dual-firing sub for octave 0). Really missing some openness and sparkle in octave 6 and above, and would much rather upgrade preamp than speakers.
I’ve only had the RP9 up and running for a couple days, but here are my initial thoughts. Its resolution is uncanny. There simply is more detail from midrange on up, but is NOT "brighter". Ride cymbals seem to extend even further than my RP7 (with Amperex 7316 in front position, that tube is no slouch!) The RP9 bass digs a bit deeper vs the RP7... it’s difficult to describe at this point, but there just seems more of everything. Somehow, the RP9 seems less "tubelike" vs the RP7, which carried the qualities of the 12AU7 type you put in it. The RP9 sounds like solid state at its best, which is fine by me. I was never a fan of overtly bloomy tube sound (though I see how some find that appealing), but I relish the rich texture and timbre that good tubes provide, and the RP9 has that in spades. One definite observation is that the RP9 has lower gain, so I have to turn up the volume quite a bit more, but that is what the volume knob is for, no worries there. I’ll see how the RP9 breaks in, but so far so good. I’ll report back again after more break in time. Edit: I have a set of NOS 6H30P-DR that I’ll plug in after getting used to the stock tubes, that will be fun!
As the RP9 breaks in (or my ears/brain adjust, in any case the sound has changed!) I am smitten by the sheer amount of detail and spacious soundstage this RP9 provides, without being over the top and/or clinical in detail retrieval. One would never consider the RP9 "warm", but man is the instrument timbre richer, deeper and straight up more enjoyable than the RP7 was. Treble decay is far more extended than the RP7, with ZERO grain. Gotta wonder what I was missing with the RP7... didn't know until this RP9. It also seriously makes my digital (thru RME ADI2 DAC) more enjoyable to listen to. This is a fine preamp. I just want to sit and listen all day. It is a natural match with Rogue Stereo 100. FWIW in the RP9 I am using NOS 6N30P-DR, and have the stock EH as backups.
The RP9 is, I think, dead quiet. When I put my ears directly next to the AMT tweeters of my speakers, I hear a FAINT hiss, but that could be from my power amp (Rogue Stereo 100), it is hard to say. One observation of the RP9 is that it runs HOT, at least as hot as my power amp. This is not just due to 6H30 tubes being taller and closer to the top of the case, they just seem to run hotter. I measured 140+F at the top of the case, toastier than the RP7 for sure.
Thanks. I remember others who have owned 6H30 tubed gear saying they tend to run hotter than other tubes.
I think the 91 db of my Wilsons and the gain of my Sachs preamp are not fully compatible. I am wanting the musicality and black background simultaneously. With differing gains, it is expected to have some level of hissss in certain combos I am told (and it makes sense). So it probably is the same matching issue with an RP9 to be aware of with amp and speakers. hmmm