McGary Audio

Essential Sound

Wednesday, February 8, 2017

Audiophile Review!
Rogue Audio RP-1
Stereo Tube Preamplifier

“Entry-Level-Priced, Made-In-USA RP-1
Is A Serious, Good Sounding Tube Pre

Price: $1,695
Likes: sonic depth, I/O, compact
Dislikes: lacks a  processor loop
Wow Factor: a worthy pre for less cash
More info: Rogue Audio RP-1

by John Gatski
  I am going to tell you right up front that the Rogue Audio RP-1 is one of the best deals out there for an entry-level priced, serious audiophile preamp. Whether you are talking tube or solid state, this compact, full-featured preamp, priced at $1,695, offers impressive sonic performance, It is not just a bang-for-the buck sonic treat, but its overall comparative performance, especially in the line stage, will turn your head. Even a picky, high-browed audiophile will smile after listening to the RP-1.

  The RP-1 tube pre is designed around Rogue’s tried and true 12AU7 twin tube Mu follower circuit, and the user flexibility is enhanced by the RP-X Rogue design that showcases active OLED screen and upgraded control via the remote.
  The RP-1 is equipped with four pairs of line level inputs, a 43/58 dB MM/MC phono preamp with internal cartridge loading adjustment, a 1-watt headphone amp and a set of variable unbalanced line outputs, a set of fixed outputs and a home theater bypass.

 I found the Rogue Audio RP-1 most impressive in how it projected hi-res music from the numerous DACs I had on hand. They all sounded terrific through the Rogue. I had three new ESS Pro chipped equipped DACS on hand including the award winning Benchmark DAC3 HGC; the RP-1 did them all proud.

  The front panel is a modicum of elegant simplicity with the center positioned, sharp-looking OLED display, a power button, balance control and the volume control.
  The back panel sports all the aforementioned connection options and a removable power cord receptacle. The seven button remote allows you to conveniently access volume, balance, selector and mute functions from your listening position.
  Though it offers a tried and true tube design, the RP-1 is a thoroughly modern preamp with large Microchip software controller (RP-X) that enables an increased user convenience through the defeatable OLED display and full function remote.

Tidy design implementation. Nice power supply

  Rogue Audio’s Mark O’Brien said he and his assemblers are proud of the quality that they were able to squeeze into the RP-1. “The RP-1 is our second preamplifier based on the new RP-X hardware and software platform. Like the RP-5 it combines cutting-edge embedded engineering with tube technology to provide a great sounding tube preamp with all of the "modern" features and technology our customers want,” O’Brien explained.
  “With the RP-1, our design goal was to develop a relatively affordable preamp that offered an extremely high level of performance in a sleek package, yet didn't sacrifice any of the features required by serious audiophiles. The audio section is based on two 12AU7 tubes in a mU follower configuration. This topology provides low noise, excellent specs and a very clean, smooth, and airy sound.”


  O'Brien noted that not only does the preamp sound good with the stock J-J tubes, but customers are reporting impressive sonics with vintage tubes as well. Spec wise, the RP-1 measurements are what you expect from a well-designed tube hi-fi product. It has virtually flat frequency response to 20 kHz (-3 at 75 kHz), 7 dB of gain in the line stage, and THD less than .1%. The preamp measures 15.25 inches wide and only 3.25 inches tall, which makes it easy to place in a busy rack. Weight is 20 pounds.

The set up
  I popped the RP-1 into my primary audiophile rack, along with the Rogue RP-5, a Pass XP-10   preamp and Coda solid state preamp that were along for the ride. Sources included the Oppo BDP-105 universal player, a Clearaudio Emotion turntable with Benz L04 MC cartridge, and my Dell tablet with the Android player: USB Audio Player Pro, which can transmit bit perfect hi-res PCM and DSD to any USB-enabled DAC.

Plenty of inputs on the RP-1

  The review system DACs included the Benchmark DAC3, Oppo HA-1 HP amp/DAC,  the Resonessence Veritas, and the Mytek Digital Brooklyn. The DAC3 and the Veritas both use the new ESS Pro 9028 D/A chip. For speaker listening, I deployed my MartinLogan Montis electrostatics, and a Pass Labs X350.8 MOSFET output amplifier, Pass' highest power stereo design. 
  All analog and digital cables, including USB and HDMI (for the LCD in order to operate the universal player) were Wireworld Eclipse; the Essence II power cords and AC outlet strip were from Essential Sound Products

The audition
  I turned on the RP-1 and let it season for three days, putting a CD on repeat while it drove a pair of AKG K702 headphones at a modest level. After the three days, I then sat down over the next three weeks and did some serious listening. First up was the Warren BernhardtSo Real SACD as recorded by Tom Jung for DMP more than 15 years ago. The title cut still has some of the best “air” around a piano and drum cymbals as I have ever heard. As the heart of a hi-fi system, a good preamp transmits the “So Real” cut’s expansive air. A mediocre preamp lessens the amount of space around the brushed drum cymbals and the upper-register notes of the recorded piano.
  With the RP-1, I was quite pleased with its ability to handle the “So Real” track's transient dimension. In fact, the RP-1 is not far off from the Rogue $3,495 RP-5 tube preamp. The RP-5 sounded a bit bigger in its overall imaging, but the timbre was very close. The RP-1 showcased a dynamic, well-placed stereo image with a discernible audible dimension around the cymbal brushes that was about on par with most good preamps that I have played through this system and the ML Montis electrostats. And the preamp is very quiet, which adds to the detail impression. Bass performance is taut, precise and balanced.

Blue OLED on black — Looks good!

  Switching off to The Anthony Wilson TrioOur Gang SACD that was dubbed to 24/192, the RP-1 threaded the needle on the title cut with its plump Hammond B3 bass lines and warm jazz guitar tone. A good preamp delivers just the right amount of bass balanced so you hear the essential plumpness of the B3 playback mechanism, yet not too much midbass that obscures the top-end response.
  The RP-1 nailed the recording, in fact, it has the quickness of a solid state preamp, but maintains that easy-to-listen to character of the better tube pre’s. Compared to the RP-5, the big brother’s only advantage was a slightly wider stance in the jazz guitars imaging. Still,  the RP-1 is about 90 percent plus of the RP-5. This is one great preamp.
  I switched off to a 2L Classical recording: The Ole Bull - Violin Concerto Blu-ray in 24/192. Like the RP-5, the RP-1 paints a vivid violin texture which is not overly thick, but with plenty of string harmonics shining through. And again, my listening notes focus on how quiet this RP-1 is. Rogue Audio really grades their tube well.

A minimalist remote that does the job

  On the 24/192 HDtracks download of the Michael JacksonOff The Wall, I really enjoyed the way the RP-5 opens up the rhythm guitar, bass, and drum focus of this  busy analog recording. And on The CarpentersGreatest Hits SACD, Karen Carpenter’s yearning-for-love voice on Rainy Days And Mondays is so hypnotic via the Rogue: rich and full as the vocal solos and then you hear all those background vocal layers that she did with her brother. What a sweet recording; what a sweet preamp.
  After all my digital fun, I plugged in the ClearAudio TT and played a bunch of records. The RP-1 did not disappoint. Although a tad less smooth than the RP-5 on ultimate vinyl playback, the RP-1’s phono preamp circuit is quite dynamic and detailed. The original Flim and The BB’s album from 1978 (Sound 80) relayed all the percussion and keyboard nuance I am used to hearing with a serious phono pre. And the Benz cartridge’s tight bass gets the handoff without any color.
  I particularly liked the bowed cello bass solo  on the The Isao Suzuki QuartetBlow Up, a recent reissue on 180 gram/45 rpm premium vinyl. The TT and phono pre must be in sync to capture that bowed bass tone with a rich cello hue. Well done Mr. RP-1.

  The Rogue Audio RP-1 is one of the best deals out there for an entry-level priced, serious audiophile preamp. Whether you are talking tube or solid state, this compact, full-featured preamp offers impressive sonic performance. Even a picky, high-browed audiophile will smile after listening to the RP-1.

  With my AKG K702 Anniversary and Shure SRH1840 HPs, I found the RP-1 headphone amp quite listenable with a tight, cleanly separated tone. Not quite as smooth as the RP-5’s all tube HP amp, but it gets the job done. And plenty of oomph to drive the AKGs.
  The RP-1 matched up with all sorts of amps: from Rogue’s ultra-accurate tube/digital hybrid Medusa, the Class-A emphasized Pass X350.8 MOSFET, my trusty Bryston 14B SSTII and the extremely clean Benchmark AHB2, both bipolar amps. There was never a mismatch.
  By the way, the RP-1 pre is not balanced, so if you a prefer long runs of balanced cables to a balanced-connector amp you will have to look elsewhere. However, I ran unbalanced runs of 12 ft. to the demo amps.
  I found the Rogue Audio RP-1 most impressive in how it projected hi-res music from the numerous DACs I had on hand. They all sounded terrific through the Rogue. I had three new ESS Pro chipped equipped DACS on hand including the award winning Benchmark DAC3 HGC; the RP-1 did them all proud.

  Not any major negatives with this budget audiophile, made-in-USA RP-1 preamp. There is no balanced connection capability and no processor loop. The former might be a deal breaker for the long cable run guys, but the vast majority of the RP-1’s customers will not care. After all, in short runs, you can’t hear the difference between balanced and unbalanced cables.

The verdict
  As I said up front, the Rogue RP-1 is a major league sounding, budget priced tube preamp with enough connection options to cover most audiophile systems. Its brilliant line stage sonics are accompanied by a quality phono section, and a capable HP amp. Plus, the RP-1 offers a modern OLED display that looks terrific, a full feature remote and a home theater bypass which adds to the pre’s versatility In my book, the RP-1 is a real winner! It gets not only an EAN Stellar Sound Award, but it also received our Everything Audio Network 2016 Product Of The Year Award.

   John Gatski has been evaluating consumer, audiophile, home cinema and professional audio gear since 1988. In 1995, he created Pro Audio Review, and he has written for Audio, Laserviews, Enjoy The Music, The Audiophile Voice, High Performance Review, Radio World and TV Technology. Everything Audio Network is based in Kensington, Md. Articles on this site are the copyright of the ©Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited. John Gatski can be reached via email:


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