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Wednesday, November 1, 2017

Audiophile Review!
Rogue Audio RH-5 Headphone Amp:
With Line Stage, Phono Preamp Option,
“Top-Tier Path For Serious HP Listeners”

Brevis...
Price: $2,495
Likes: clean detailed HP path with line pre
Dislikes: like it all, but please add a DAC
Wow Factor: a must-audition for HP fans
More info: Rogue Audio RH-5

by John Gatski
  I have owned numerous Rogue Audio products since 1998, and currently run a RP-5 as my reference tube preamp and a Medusa as my Class-D amplifier. Rogue makes all kinds of tube components, and a few preamps with a headphone circuit, but the company never has made a focused separate headphone amp — until now.
  Rogue Audio President, Founder and Chief Designer Mark O’Brien have remedied the standalone HP amp omission with the new RH-5, a dandy, full-featured headphone amp/line-stage preamp that exemplifies a state-of-the-art tube /solid state design that gives you a low-noise, and hi-res playback finesse — without the excessive color of many HP amps.
  Priced at $2,495, the RH-5 is a HP amp with several unique design aspects that O’Brien has implemented to get the best out of good-sounding headphones.
  “Because the requirements for a headphone amp are very different than for typical stereo preamps or power amps the RH-5 is a unique design that is quite different from any of the other gear we make,” said O'Brien. “I wanted it to be a tube design but creating a tube-based headphone amplifier has some very unique challenges."

  Rogue Audio has  taken the traditional HP amp circuit applied a bit of custom, hybrid circuit magic, and netted a fantastic-sounding, HP listening path that you would not believe is tube; it is that quiet!

  He explained: “the basic circuit uses a pair of Russian-manufactured, low-noise 12AU7tubes in a mu-follower circuit configuration, followed by high-power MOSFET buffers. Pretty much all of the voltage amplification is done in the tube domain, while the buffers provide the current to drive the most difficult headphone loads.”
  O’Brien said the hybrid design approach offers the best of solid state and tube in terms of  its sonic attributes. “I really like this circuit because it offers the great sound of tubes, yet is super quiet and very powerful.” O’Brien noted.
  Besides the sophisticated, modern, hybrid design approach, the RH-5 also utilizes Rogue’s RP-X technology platform, which is a DSP engine that offers more modern control of the gain, more efficient and quieter switching as well as a host of connection options. I love that 30 second countdown upon start up as the circuit stabilizes.



Features
  The RH-5 connection cadre includes three pairs of RCA inputs and one pair of balanced XLR inputs. Headphone outputs are provided via fully balanced, 3-pin and 4-pin, fully balanced outputs, as well as two 1/4-inch TRS headphone jacks . The extra 1/4-inch jacks enables the two-listener option, such as in a pro audio tracking/mixing room and for audiophiles who like to test different headphones via a really good HP amp.

Not only is it a HP amp, but it is a full-festured line preamp

  Three gain settings allow the output to be matched for either high, medium or low-sensitivity headphones. An easy-to-read OLED display elegantly communicates component settings and volume. The display can also be turned off, if desired, for those who like the dark side of HP listening. The included remote allows you to turn on the RH-5, change volume, select source, mute output and dim the display.
  The RH-5 is not just a superb headphone amplifier, it can also be used as a line preamp with balanced and single-ended preamplifier outputs. And if all that is not enough, an optional phono board enables quality, vinyl playback through either the HPs, or line out to an amp and speakers.

 “Because the requirements for a headphone amp are very different than for typical stereo preamps or power amps the RH-5 is a unique design that is quite different from any of the other gear we make.”
Mark O'Brien
President, Rogue Audio

  The onboard MM/MC phono pre offers user-adjustable gain settings of 43 and 58 dB to accommodate most cartridges. A wide variety of loading options also means your favorite cartridge can be configured to sound its very best.
  Although there are numerous HP amp/DAC combos on the market at various price ranges. Rogue Audio did not go down that road (this time). However, this hybrid RH-5 design is so impressive, I bet if they did design a HP/amp DAC, it would be a killer. After all, Mr. O’Brien knows a thing or two about digital products. His digital/tube hybrid amps are top class in their respective niches.
  For the RH-5, however, O’Brien simply stated: “Most people using this level of headphone amp would prefer to use their own dedicated digital gear.”

 Rogue Audio RH-5 Specs:
- Tube complement: 2 x 12AU7/ECC82 tubes;
- Frequency response: 5Hz – 50 kHz +/- 1 dB;
- THD: <0 .05="" font="">
- Gain line stage: 3dB/12dB/16dB (selectable;)
- Rated output: 3.5W (32Ω);
- Output impedance: <0 .1="" font="" khz="">
- Gain phono stage: 43 dB, 58 dB;
- RIAA accuracy: +/- 0.1 dB;
- Phono overload: 40mV;
- Power consumption (On): 31W;
- Dimensions: 15”W X 13.5 ”D X 4” H;
- Weight 19 pounds.

The set up
  I installed the RH-5 into my audiophile system for the review, feeding it with several DACS and then driving several headphones over a two-week period of serious listening. The HPs included a pair of Sennheiser HD-650, Shure SRH-1840 and AKG K702/K812, and Oppo PM-1 planar magnetic.
  I also used the RH-5 as line-stage preamp with the various DACS as sources, including Benchmark DAC3-HGC, Oppo Sonica, Prism Callia and Mytek Manhattan II. For comparison purposes, I had on hand a Rogue Audio RP-5 line preamp.
  All speaker listening was done via MartinLogan Impression. Cabling was courtesy of Wireworld Cable. The AC cables and distribution were provided by Essential Sound Products. Since Rogue Audio burns in all their products before they ever hit a dealer (or reviewer), I hooked up the RH-5, let it stabilize for 10 minutes and began my listening.

The audition
  First up, I played the Everything Audio Network reference track I always start most listening sessions with: Warren Bernhardt "So Real," the ripped DSD tracks  from the DMP SACD of the same name.
  This live-to-two-track direct DSD recording from the early 2000s was recorded by Tom Jung, and the stereo is simply awe-inducing with a great HP (or speaker system). Percussion sounds, such as cymbal brushes and snare rim shots are incredibly real sounding, as is the warmth of the bass and the precision resolution of the Steinway grand piano.
  The Rogue Audio showcased the “So Real” track with that wonderful, wide spacing of the instruments, and it is oh-so quiet for a tube HP amp. If you are a listener of traditional tube circuits, you would swear the RH-5 is all solid state.
  The RH-5 also passed the upper-register piano textures of the Steinway piano with that unique tinkle and slight reverb decay that the better audio products are capable of delivering with this track. Lesser headphone amps seem to muss up that bit of room reverb projection in that track — with their narrower soundstages.

Good design, good parts = great sound!

  I auditioned Gene BertonciniBody and Soul, an album with a slew of jazz standards played on a nylon-string guitar, exquisitely mic’d in stereo and recorded straight to DSD. Again, the RH-5 revealed the wide spacing of the stereo recording setup, and fully fleshed out nylon string note runs as played by Mr. Bertoncini. The tube microphone warmth embodied in the recording was intact, but not over-bloomed.
  Sticking with the acoustic guitar theme, I played the recent reissue of the YesFragile, the latest Steve Wilson mix at 24/96 on Blu-ray, using a Oppo UDP-205. Guitarist Steve Howe’s “Mood For A Day” acoustic guitar masterpiece. The RH-5 really nails the track, showcasing Steve Howe’s  dynamic pick attack, a very full, defined stereo image and that subtle warmth often lacking in  today’s Rock solo acoustic guitar recordings that use inferior, internal guitar pickups.

Yes - Fragile remix/remaster sounded great via Rogue RH-5

  Moving on to Classical music, I played Joshua Bell’s Tchaikovsky in D Violin Concerto DSD recording on SACD, via the Oppo 205. Listening through my AKG K702 Anniversary HPs, I wanted to hear whether the Rogue could relay the vibrant, but not harsh, violin texture of Bell’s instrument. Sometimes HPs and HP amps combine to add an over stridency to the violin, the delicate balance of high-frequency, wood/string/bow energy becomes hard edged. It always gets blamed on the digital, but it is not always the case. The HP amp can exacerbate stridency.


  Again, the RH-5 revealed the wide spacing of the stereo recording setup, and fully fleshed out nylon string note runs as played by Mr. Bertoncini. The tube microphone warmth embodied in the recording was intact, but not over-bloomed.

  The Rogue Audio RH-5 added not one bit of extra edge to the violin recordings. The AKG’s sounded as smooth with the Tchaikovsky as I have heard it through headphones. I noted the same transparency when playing several Heifetz, Midori  and Hillary Hahn violin recordings.
  Classical lovers who are headphone users will also love the RH-5 on symphonic music. I recently purchased the RCA Red Seal “Living Stereo: reissue of the 1950s BerliozSymphony Fantastique, and fell in love with this version: incredible analog smoothness with great dynamic power when the orchestra goes full force, especially in the fifth movement.
  On my Oppo PM-1 planar magnetic headphones, which I ran balanced from the Rogue’s balanced HP output circuit, the Berlioz Symphony was indeed fantastic.!Such smooth, yet powerful brass and strings. Hard to believe it was recorded 60+ years ago. The dynamic range of the fifth movement is such that you have to turn it down when it reaches the crescendo.

Its only Rock N‘ Roll
  On Rock/Pop music, such as the Yes reissue and numerous, other well-recorded albums, the RP-5 is very good at resolving the complex path of multitrack mixes and transmitting listenable audio directly to the ears. Daft Punk’s "Get Lucky,' with that funky Nile Rogers rhythm guitar and disco drum beat, came through with ample air around instruments and a warm, kick drum presentation.

  On Gene Bertoncini — Body and Soul, an album with a slew of jazz standards played on a nylon-string guitar, exquisitely mic’d in stereo and recorded straight to DSD, the RH-5 revealed the wide spacing of the stereo recording setup, and fully fleshed out nylon string note runs. 

  My Led Zeppelin and Nirvana hi-res downloads got the royal treatment from the Shure SRH-1840 open ‘phones and the RH-5. Its smooth, low-noise persona showed that the midrange-heavy overdriven style of Rock did not get overly charged by the playback electronics and HP drive. That separates the men from the boys when it comes to good HP design.
The line stage
  Since the RH-5 is billed as HP amp, by golly that is how I used it — mostly. But since it offers a fully featured line stage (as well as the optional phono stage, which I did not have installed), I played everything that was monitored by headphones through the line-out to the Pass amp/ML speakers.
  Sonically, the line stage is a great bang-for-the-buck, balanced and unbalanced audio pathway for those who who like to use their HP amp and line preamps in one box. However, the RH-5’s line stage is not as revealing as the Rogue Audio RP-5, which has more of that tube richness and image openness, while the RH-5 sounds more solid state. Mr. O’Brien terms the RH-5 as “a great headphone amp with a good, entry level, line stage.” I agree.


  I had not one single complaint about the RH-5, through the 100 hours or so of listening over several months, it had no problems. No tube noise, and the remote worked perfectly — even when I aimed it off center of the IR receiver on the front face plate.
  As with the RP1 and RP-5, I love the 30 second countdown as the tubes warm up, The RP-X switching and control engine is a major step up over conventional analog controls, routing and switching, and it gives the Rogue a much higher-end feel and operation precision.

The verdict
  Rogue Audio has  taken the traditional HP amp circuit applied a bit of custom, hybrid circuit magic, and netted a fantastic-sounding, HP listening path that you would not believe is tube; it is that quiet.
  Couple the great sound with its massive drive capability, full array of connection options and a top-tier line stage (plus an optional phono stage), the RH-5 is all that most HP-focused audiophiles will ever need. I nuzzled up to it, immediately, with my Austria-manufactured AKGs and never looked back. I guess I liked it. Stellar Sound Award? You betcha!
  By the way, I believe that a HP circuit this good should have a digital converter attached to it. I would like to see a version of the RH-5 with a built-in DAC. Are you listening, Mr. O’Brien?

 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: everything.audio@verizon.net



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