Equipment Review No. 3 November 2001
Rogue Audio Tempest Integrated Amplifier
Rogue Audio, Inc.
|Tube-based stereo integrated amplifier; 4 KT88 tube output section (according to manual but mine came with 6550's); Triode (40W) or Ultra-Linear (60W) modes; 4 or 8 ohm selection; can be used as a power amplifier with an external preamplifier or in a biamplified setup using a Rogue Eighty-Eight power amplifier; 5-way binding posts; 5 pairs of unbalanced inputs; passive and active output; remote control; 18.25 W x 15.75 D x 7 H inches; 60 pounds; 6 month warranty on tubes and 3 year warranty parts and labor on everything else.|
B&W CDM7 NT loudspeakers, Krell KAV-280cd, Creek 5350SE (for comparison), Audioquest cabling.
Basic Setup and Functions
The Tempest comes in a large box with the output tubes packaged separately. When I first pulled the plastic off the main unit I noticed a piece of board attached to the bottom. At first I thought, "oh, great-- they sent me a half assembled unit," but then I realized it was only to keep the unit safe during shipping. That makes sense. One of the side panel screws was off and fell out of the plastic, but this was no big deal, as I had to open the unit to insert the tubes anyway. The amplifier automatically biases the tubes, so after insertion I was about ready to go. Once I opened the manual it was quite clear what to do next, so I checked the output impedance setting and the mode of operation.
The unit came preset for 4-ohm speakers and I began the listening tests with this setting. Unfortunately it is necessary to open the cover and unscrew the binding post in order to change wires to affect the change. In normal operation it wouldn't be a big deal (because the unit would presumably be used with one set of speakers), but most amplifiers offer taps on the back so it is not necessary to take the amplifier apart.
The Tempest also allows for operation in either Triode or Ultra-Linear mode. I began listening with Ultra-Linear mode and then changed to Triode mode later on in the testing. It is necessary to flip four switches on the main circuit board to change modes. Again, it would have been nice to have these switches external, probably on the back of the chassis. I don't like sticking my hand inside an amplifier any more than I have to, but the directions in the manual are clear about safe handling.
The power cord that comes with the unit is nothing special, so power fanatics may want to consider an upgrade. I preferred to use the unit in as much a "stock" situation as possible, so all my comments apply to use with the standard cord.
Another feature offered by the Rogue Tempest is the ability to be used as a basic power amplifier along with an external preamplifier. I'm not sure how many people would want to bypass the line section of this unit-I mean, after all, that is why you bought an integrated amplifier for in the first place, right??
Switching functions worked perfectly during my tie with the unit, and the volume control has a very nice feel. The control is large, so any use of it is very positive, and it is easy to grip. The remote control worked extremely well and even from angles well off 60 degrees. There is only volume up and down, so you won't be cooking breakfast with this one. It is very solid and has a very high-end look and feel. On the front of the unit there is a mute switch as well. It didn't turn the sound off completely, but there was very little coming out of the speakers while it was pushed in. The Tempest only took about 20 seconds to warm the tubes up and get sound to the speakers. All of the listening in the listening tests allowed for a lengthy warm up time-sometimes several hours. With some of the comparison tests I was forced to turn the unit off for fear of damage with an open load at the terminals. This may have been a non-issue, and will definitely be a non-issue in a typical listening environment.
Aside from some clicking sounds when the unit came on and turned off, there was very little noise that could be attributed to the operation of the Rogue Tempest. The one exception is the fan. It was audible in a quite room when I stood close to the unit. With about six feet of distance I could not hear it. It is rather large (5" in diameter), and is located on the left side of the unit. It pulls hot air outside of the chassis, so the rest of the area surrounding the amplifier is relatively cool. If you stick your hand next to the fan you can feel that the left side can get fairly warm. The one problem with this is for people who have tight cabinets width-wise. You need to make sure there is adequate ventilation for any amplifier much less a tube amplifier. I'm not sure why the fan does not work towards the top or the back, but Rogue must have their reasons.
Break-in period was over a week. I decided to leave the unit on and play continual music for this period of time. (Yes, I have forgiving neighbors.) I didn't do any serious listening during this period although the unit sounded fine right out of the box. I did note that the tubes I received were 6550's and not the KT88's that are advertised. The sound with the KT88's or even with different tubes may have improved the sound. The stock tubes were Electro Harmonix.
Listening- Part I (4-ohm, ultra-linear)
I began the listening with track 5, "Cripple Creek Break-Down" from Sheffield Labs' Crème De La Crème. I noticed right away that I had to turn up the volume higher than I thought was safe. I had it almost two-thirds to three-quarters of the way up. I realize that this CD may not have been a good representative of the level from most consumer discs, but I was still surprised at how low it was. I tried a different CD player briefly to determine if just the Krell's output level was to blame. Alas, it was the same with the other unit. Note: There was no harm to the unit or noticeable negative effect with the volume at this level, but it was disconcerting nonetheless. Later in the testing I noticed that I had the volume more towards 12 o'clock (mid way) and it seemed to be more than loud enough.
I should mention that I initially connected a pair of Nautilus 805 speakers to Rogue and was very disappointed. There was literally no life to the sound. Break-in took place with a pair of Revel F30's, and sound was more than acceptable, so speaker matching will be a factor. I figured the 805's were a bad match and having a pair of CDM7's handy helped. The CDM7 NT's were a great match for this amplifier. I had heard that the Rogue pieces work well with Vandersteen speakers, but I didn't have any to try out. As with any piece of equipment, matching plays a part in the overall performance of the system. The Rogue seemed to take away a little bit of the extra high frequency "zing" that these speakers can have with other equipment.
The sound was polite, relaxed, and easy. The soundstage started from slightly in front of the speaker and extended back. It did not go quite as far as I've heard with these speakers, but it was not flat by any means. Images themselves, were big and spread out, but not too big. The size of everything seemed about right. Bass was full and I could distinguish between various notes in the low frequencies, but the sound came across as a little fat. Dynamics were not as impressive as some high power solid-state amplifiers, but the sound was not restricted. Transients were fairly good which helped to further the illusion of live sound. The background was relatively quiet although not black. Hiss was not evident whatsoever. I noticed a slight blending of instruments, and that softened up the whole image. There was no harshness and very low grain. I felt that the Rogue was taking the edge off of some of the high frequencies. There was air around instruments and the acoustic space was discernible, but not as deep and 3-D. Cymbals seemed to have a "squishiness" to them (perhaps only a term with meaning to fellow tube listeners), and loud transients were blunted a tad. "Easy" is the way I would describe the sound.
After listening to this first track I was in a mellow mood. I put on "Ce" from Toots Thieleman's The Brasil Project, Volume II. I noted nice reverberation from this track, but I felt the background wasn't perfectly delineated. The harmonica sound was soft and smooth. When the sound got sharp and loud the amplifier seemed to deliver the goods with no trouble. It was clear that within the power limits, the amplifier did a very nice job. Read on (below) for results of higher volume testing. Voice, I thought, was beautiful and natural. The shakers (maracas) didn't have as much bite as I remember. I began to recall my experiences with an old Dynaco Stereo 70. The Tempest does have a tendency to do a little softening, but not enough to be considered a drawback. It is more of a choice. With many of the speakers that could be mated with the Rogue, this actually might be a very good thing! I can't say that I haven't heard quite a few bright speakers in my day. A little edge and a little smoothing added up to a lotta good sound. The guitar plucking on this recording blended in rather well with the other instruments in the mix, and yet individual tones could be picked out from the sonic tapestry-not as well as megabuck systems, but better than most. Bass was not as defined in the low end as I'd like, but this has something to do with the loudspeaker in use. The sound from the Tempest never jumps out and grabs you. It is more like a nice, warm, comforting blanket-not too heavy, just soft, easy, and inviting.
I switched to something a little different: track 5, "Kiko and the Lavender Moon" from Los Lobos' Kiko. This is a fairly good recording and the Rogue did a nice job. Guitar was appropriately gritty, and the sound was very spacious. The drums were lively, and the voice just seemed to hang in space. There was a good sense of depth, and the Tempest did a nice job handling the dynamics and dynamic shifts within the recording. At higher volumes things got a little restrained, but I felt that I was turning up the volume louder than I normally would due to very low levels of listener fatigue at lower volumes. For those of you who are stuck on tube sound and are looking for an upgrade to an older tube product without spending a fortune, then the Rogue might find a happy home. The percussive sounds are very present, and they have an almost "touchable" quality to them. Occasionally I could hear instruments and sound beyond the edge of the speakers.
In order to test the true loudness capabilities of the Rogue I put on track 1, "Cherub Rock" from Smashing Pumpkins' Siamese Dream. I really let loose with the cut and cranked it up. Let's face it; this amp is not for people who want to listen at rock concert volumes (or even near them.) The bass began to get mushy and high frequencies were a mess of guitar and all blended together. Some of this is recording related, but lower level playback seemed to bring things back under control. Vocals and other low-level information did not shift in position in the soundstage, but the sound seemed disjointed in some way. It was not concise, focused, separate, dimensional, or in the proper perspective. Some of this might be alleviated by biamping. But really the answer was just to turn the volume back down. Anyone auditioning this amplifier would be best to determine if there is truly enough output for their listening taste. Again, this is not any different with any other power or integrated amplifier. I wondered if a switch to the 8 ohm setting might help in this regard, so...
Listening- Part II (8-ohm, ultra-linear, Creek 5350SE comparison)
I switched the amplifier to the 8-ohm setting and allowed it to warm up. I cued up the same Smashing Pumpkins track and listening again. For some reason the sound seemed to stick together better. This didn't really make sense to me, but I continued to use the amplifier with this setting.
It was time to do some comparison listening. I happened to get a hold of a Creek 5350SE integrated amplifier, and thought it might be interesting to compare highly rated solid state integrated with the Rogue tube integrated amplifier. Just to be fair I should mention that the Creek sells for about $700 less, so the comparison was not entirely even. The first thing I did was take out my multi-meter and match levels as best I could. I used track 1 from the Stereophile Test Disc #1. After I picked a fixed volume I began the listening sessions.
I started with a simple acoustic cut, track 4, "Batidinha," from Antonio Carlos Jobim Wave. On the Creek the cymbals had a more metallic sound. There was a more noticeable "scratch." The guitar was very tight and defined, but didn't come across as lush as with the Rogue. With the Rogue the low bass was more present. Guitar sound was actually more defined and realistic. The tone of the guitar is more of what I expect to hear. Background sound was brought up closer in the mix and the sound was richer. Also, the sound was more spread out and less confined. The high frequencies had more of a "whiteness" to the sound.
Diana Krall decided to come and play track 4, "Frim Fram Sauce," from All For You. The Creek presented the piano with more clanginess. Voice was more locked in than with the Tempest. Image was slightly smaller, but the recording had seemingly more air. Voice had a colder sound to it through the Creek. The soundstage was not as wide as with the Rogue. There was a consistent change in tone to the sound with the Creek in comparison to the Rogue. It is hard to describe, but easily detectable through listening. The Rogue rendered the piano very nicely. The image itself was pleasantly large. Diana's voice was more in the room and had a slight reverberant quality to it. Not to sound silly, but the voice had a more Etta James quality to it. There was not as much air as with the Creek around individual images, but more overall space. Overall the sound was much warmer.
From Delos DE 3167 I listened to Debussy: Sonata for Flute, Viola and Harp, I. Pastorale- lento, dolce rubato. The Creek emanated the feeling of great accuracy of tone, and was clean and grain-free. There was an excellent delicacy to the sound, but it was not as warm as the Rogue. The Rogue Tempest obviously imparts euphonic warmth to the music. Micro-dynamics and transients are a tad slower than the Creek, but don't really affect the enjoyment of the music.
There was no need for any further comparison testing as the differences between these two pieces were quite evident, and selection of either one will depend on speaker matching and personal taste. To further test the capabilities of the Rogue I switched to triode mode and testing resumed.
Listening- Part III (8-ohm, triode)
I was trying to figure out a good way to compare the differences between the triode and the ultra-linear modes, but gave up. This amp will require the end user to try two different configurations (not including tube switching, changing power cords, etc). The first is the 4 and 8-ohm settings, and the second is the mode of operation (triode or ultra-linear). I put on "Brushes & Brass" on Live At The Village Gate by Clark Terry. Right away I had to turn up the volume more than usual, but if this doesn't bother you in the ultra-linear mode, then it really isn't a concern in the triode mode either. I never felt like I was running the amp into distortion, only that I seemed to need more gain, and I achieved this by a minimal turn of the volume knob. Everything about this track made me think about what a nice acoustic feel I was getting. Images seemed to be slightly smaller than what I would consider realistic sizing, but this may have been recording related. Depth was good. The Rogue had nice attack and decay although I'd guess it wasn't as fast as some other amplifiers. Overall the sound was very pleasant and easy to listen to. Vocalizations sounded very impressive and almost "in the room." Brushes had an easy sound as well. Images weren't as focused in space as much as I'd like, but tonally they sounded great. If I were to make an analogy it'd be like the difference of a standard light bulb in comparison to a soft white bulb. Listener fatigue was not an option. I could have sat and listened for days, however, I was never amazed or excited about the sound-just content.
Next up was "Tricycle" from the Flim & The BB's album Tricycle. The character of this amplifier is very evident on no matter which type of recording I listened. It was starting to remind me of that old sweater or recliner that you just can't get rid of. It was smooth, soft, and sublime. The transients on this cut just seemed to hang in the air and then slowly fade away. The background was not completely black, but had a soft quality to it. This was definitely recording related. Listening to this cut impressed me a great deal. Some amplifiers have a tendency to make this cut sound flat, but the Rogue managed to give it life and make it quite enjoyable.
I'm definitely glad that I decided to try the triode mode. It didn't seem to decrease the sound quality in certain areas like I expected, but it did seem to lend something indefinable to the musical presentation that gave the music more realism and power-in the sense of the ability to communicate the meaning of the piece. With track 9, Bach: Goldberg Variations, BWV 988, Aria from the Delos Spring Preview 2001disc, this was clearly evident. The sound was polite, sweet, and basically "ear candy." Tones of the harpsichord practically eased out of the speaker with no strain, disharmony, or edge whatsoever. With the Rogue Tempest it is not hard to hear the qualities in the music that attracts people to tube equipment in the first place.
I often forget how steadfastly certain audiophiles defend the merits of solid state or tube equipment. It reminds me of a holy war with almost as much dogma and debate as what you would expect in religious discussions. I divide audiophiles up into two categories: the equipment/ hardware lovers and the music/ software lovers. Of course there are hardly any absolute believers although I've met some! But what does this have to do with this review? The important point is sometimes it is necessary to hear two different things/ sounds/ pieces of equipment just to know that it is time to change components or to stay with what you have. I encourage everyone to at least listen to a tube piece of equipment if you have never heard one before. The Rogue Tempest was a striking reminder to me as to why a person would invest money in tube equipment. Not to say that the Rogue is a perfect integrated amplifier, but to say the reasons it is imperfect are possibly what make it so wonderful. When I was listening to the amplifier casually I could not help but enjoy the music. If you are looking for an inoffensive, polite, pleasant, easy, relaxed, or mellow integrated amplifier to listen to music at moderate levels then you owe it to yourself to check out this piece.
- Brian Bloom
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