KR AUDIO VA880
TUBE INTEGRATED AMPLIFIER
Dr. John Richardson
KR Audio, lately of the Czech Republic, has been around for nearly 20 years, as designers, builders, and purveyors of fine vacuum tube gear and... vacuum tubes. Yep, they roll their own! I’m not sure if they sell more amps or tubes, but they’re most definitely focused on pushing the technological envelope in both areas. Furthermore, the company and its erstwhile leader, Dr. Eunice Kron, are no strangers to us here at Stereomojo. A couple of years ago I had the opportunity to spend some quality time with one of the VA880’s bigger siblings, the Kronzilla SXI stereo integrated amplifier. This amplifier impressed both me and publisher James Darby greatly. One thing about the Kronzilla that grabbed hold of me was that it didn’t sound much like a classic tube amp; I recall saying that it had a sense of accuracy akin to what I might expect from a mythical “perfect” solid state amp. James said that it didn’t sound like solid state or tubes, but like live music, pure and simple. It was a big, accurate, intimidating bugger, and boy did it sound good!
Not too long before Rocky Mountain Audio Fest 2012, I was contacted by Mr. Darby asking if I’d like a crack at reviewing a smaller and less expensive KR Audio integrated amp. Recalling how much I enjoyed the Kronzilla, how could I refuse? I also wanted to see what KR Audio could do on a smaller budget (e.g., $6000 vs. $18,500 for the Kronzilla). And since I was traveling to RMAF, I’d get a chance to hear the VA880 in action under show conditions and, more importantly, finally get to meet Dr. Kron.
Sure enough, I found her in the Antelope Audio room, holding sway with the good folks there. I had expected Eunice to be European, like her late husband and company founder, Dr. Riccardo Kron. Turns out that she originally hails from Brooklyn and is a doctor of veterinary medicine, so maybe my analogy between amps and household pets wasn’t so far off after all. As there was a lot of gear about, I tentatively asked Dr. Kron if it was indeed her amplifier, the VA880, driving the big Von Schweikerts in the room. Her reply went something like this: “What do you think it is, five mice on a wheel?” I knew immediately that we were going to get along just fine! After a fair bit of chatting, I learned from Dr. Kron a lot about what’s behind the VA880 which was to shortly grace my listening room.
Firstly, the chassis of the VA880 looks a lot like a squat, scaled down version of the Kronzilla. Think of it as a baby Kronzilla, if you will. The other major difference upon first inspection is the row of four KT-88 output tubes lined up on the top panel. A far cry from the massive pair of custom KR transmitter tubes found on the Kronzilla. Why KT-88s? As Eunice explained to me, lots of customers wanted a non-custom output tube so they could inexpensively (relatively speaking) engage in tube rolling among different manufacturers; further, the tubes are easier to source and replace when that time comes. Even Dr. Kron acknowledged its friendliness when compared to the monster Kronzilla, which, as I found out, requires some special care and nurturing to sound its best.
Despite the differences, the VA880 actually shares a lot of the same technology as the Kronzilla and other much more expensive KR offerings. For instance, it’s what we might call a “reverse” hybrid design. As an integrated amplifier, the VA880 contains preamp and amplifier sections, both of which are active. The unusual part is that the preamplifier section is solid state, employing MOSFETs as the amplification devices while relying on the KT-88 tubes as the main amplifier output devices. Most other hybrid designers go at it from the opposite direction, using tubes in the preamplifier stage and solid state devices in the output section. As I found out during the Kronzilla review, this is apparently the wrong way to go about things, as the amplification devices are not optimized to their intended purposes: MOSFETs like to provide lots of current in response to a small voltage change, and this current can be best utilized to drive the large voltage swings that vacuum tubes are capable of providing at the output end of the amp. Well, I can’t say much more about optimal circuit design, but I can say from first-hand experience that I think the folks at KR Audio are onto something.
Looking at the VA880, I see a compact but sturdily built unit with no apparent construction shortcuts. It weighs plenty, but (unlike the Kronzilla) I can move it around by myself. The chassis has a distinctly post-communist Eastern European look to it that reminds me of form following function in an appropriately utilitarian, but good-looking package. The amp itself is painted sort of a matte black all over, which is highlighted by chrome knobs and buttons up front, along with the gold KR marquee nameplate. Oh, and of course the tubes, along with the optional shiny metallic cage. While the amp looked nice with the cage on, I preferred the look with the cage off, so off it stayed.
There is no internal phono stage and no preamp out, so folks with subwoofers will need to find other ways to integrate them. I just left mine out of the system during the evaluation period. There are, however, four line-level inputs as well as stereo speaker outputs. The main on/off switch is on the rear panel of the amp while the standby button is found on the far right side of the faceplate. The volume knob is located dead center and is larger than the other controls. Embedded in it is a red LED which lights up when the amp is brought out of standby and is ready to operate.
Also accompanying the amp is a nice metal remote which I used liberally to control the volume and bring the amp in and out of standby from my listening position. You can also switch between inputs remotely. Excellent remote.
In a hidden compartment on the rear panel, users can choose between four and eight ohm output taps.
Since the VA880 is a push/pull design, it puts out more power than the Kronzilla, which was single-ended. I found its 50 watts per channel to be plenty of power to drive my Shahinian Compasses; I never felt like the amp came anywhere near running out of gas, as I experienced no audible clipping or compression of dynamics.
During the evaluation period, music was sourced from either my homemade Mac Mini based server (described in detail in previous reviews) or the swanky Your Final System (YFS) HD Ref 3 Special Edition music server (review forthcoming). In either case, digital data were sent to an Antelope Audio Zodiac DAC for conversion to the analog domain, and then to the KR VA880. As I mentioned before, my Shahinian Double Eagle subwoofer was left out of the system, with the VA880 feeding only my Compasses.
The only setup issue worth mentioning is that I initially found it hard to bring the amplifier out of standby. After the appropriate warm up time had passed, I heard a click, followed by a moment of buzzing in the speakers, followed by an automatic return to standby. Another try usually solved the problem, but it was obvious that something wasn’t quite right. A quick email to KR Audio took care of things: apparently I had at least one bad output tube. Within a couple of days a new matched quad of KT-88s was in hand and installed, immediately solving the problem.
After my exposure to the KR Audio Kronzilla, I expected the VA880 to sound good, and in this respect I was most certainly not disappointed. But how well could it stack up against its three-times-as-pricey cousin? Amazingly, quite well indeed, if my aural memory is what I think it to be. My immediate impression was that the VA880 sounded more like a tube amp, and I mean this in all the good ways. As I said before, the Kronzilla was deadly accurate. It did space beautifully in the grandest tradition of tube amplification, but it was fast, tight, and somewhat angular, with a great ability to nail pace, rhythm, and timing. I thoroughly loved it, but it struck me as not necessarily an amplifier that someone looking for the traditional “tube sound” would be satisfied with. I suspect that many folks who buy tube amps want them to sound like tube amps, at least to some degree. And I think this is the crowd that will be most pleased with the VA880. Does it sound fat and tubby? Not at all. Are the frequency extremes attenuated? Not that I can hear. But it does have that somewhat rounded sculpting of the notes that good tube amplification is noted for; that certain quality that gives such amps a pleasant tone and hefty presence. However, I never felt like these things were present in great excess, to the point where the music became so dark, syrupy, or flabby that there was an apparent loss of resolution and detail. In fact, fellow reviewer John Fritz, who has always owned tube amps, remarked that the notes weren’t as rounded as he is used to hearing via his high dollar Audio Research gear. What we have here, in my humble opinion, is a highly effective combination of the best attributes of tubes and solid state, while avoiding the sonic pitfalls of each.
If you’re a fan of classic rock ‘n’ roll and haven’t yet experienced Led Zeppelin’s live reunion album “Celebration Day,” then I’d suggest that you immediately seek it out. While the performance showcases some good old fashioned hard rocking, what really stands out to me is the interaction of the crowd, which screams, sings along with the band, and carries on in any number of other ways. When cranked to essentially excessive levels, this recording takes me back to earlier days of attending such live events. And the VA880 surely rocked! Forget polite, as this amp helped make me feel like I was there in London in 2007, as the sense of spaciousness and immediacy was breathtaking. The apparent soundstage was huge and deep, with the band up front and the crowd forming a huge sweep of sound waaay off to the sides and well behind the performers. Who says that amps with tubes don’t do rock ‘n’ roll? Well, most guitar amps used by rockers are tube amps, so it would be a pretty silly supposition to say they don’t! ~publisher
Speaking of spaciousness and immediacy, an album that has gotten lots of rotation lately (in the digital domain, alas) is Volume 4 of John Ireland’s Orchestral Works (digitized LP, Lyrita SRCS 45). This whole disc is a sonic blockbuster full of accessible, but not necessarily cerebral music of a definite cinematic flavor. If, like me, you enjoy rousing symphonic works with lots of silky strings, staccato woodwinds, and blustering brass and percussion, this LP is right up your alley. Luckily, it’s also available on CD for those of us who prefer not to spin or digitize vinyl.
While I love the whole thing, I feel that the best demonstration/evaluation piece is the final work on the disc: “Scherzo and Cortege on themes from Julius Caesar.” This work starts with a bracing brass fanfare, which emanates from the right rear of the soundstage. Via the VA880, there was plenty of bite and brassiness present, but without the excessive sibilance or glassiness which is sometimes heard in the reproduction of brass sound. I also felt that the instrumental placement in the soundstage was just right; definitely behind the strings and woodwinds when they come in. I could easily “see” the precise locations of the various instrument types both with regard to lateral placement and front to back depth. In short, I was fairly easily able to suspend my knowledge of this as a recorded event and transport myself to the actual site of the performance. Instruments had the tonal qualities of real life, augmented by the spaciousness and sense of weight one hears during a live performance of a large orchestra. I also got about as much pleasure out of listening to this work quietly as when I goosed the volume to realistic live levels.
Jazz was sublime using the VA880 as well. I had never heard of pianist Warren Bernhardt until just recently, when I had the opportunity to hear his album “So Real” (hybrid cd/sacd, DMP), a compendium of jazz standards and show tunes, all arranged in a beautifully lilting manner that shows off Mr. Bernhardt’s talents. He is supposedly a protege of Bill Evans, and it certainly shows in his playing. Listen to the opening bars of “Somewhere” and you’ll think you were listening to Evans soloing at his best. Through the VA880, the piano was reproduced beautifully, with plenty of body, extension, and decay. The same can be said of the other members of the trio, as the drum kit and string bass were as real, palpable, and soulful as one could want. Of course, this is a lovely recording, and the VA880 was just helping to bring out the best of it.
As good as the KR VA880 is, I was eager to make some comparisons. The only other somewhat comparable integrated amp I had in house at the time was the REDGUM RGi60ENR, the little brother of the RGi120ENR that I reviewed not so long ago. This amp is rated at 75 watts per channel (RMS) and retails for right around $2600 (usd) with the remote control option. While the reviewed RGi120ENR comes closer to the KR amp in cost, it is considerably more powerful, so I thought that the RGi60ENR comparison might actually be more reasonable, as the power ratings are more similarly matched. As a bit of a review, the REDGUM integrated is a solid state MOSFET design with a passive preamp section focused on simplicity, durability, and short signal path. Think of it as more of a stripped down race car as opposed to a big, comfortable Cadillac.
As solid state goes, I have been very favorably impressed with the REDGUM offerings. The RGi60ENR is fast and transparent, but avoids that somewhat lean tonal character that often goes with the previous two descriptors. To me, the REDGUM designs represent a superb overall implementation of solid state design.
That said, I actually found more similarities than differences between the REDGUM and KR amplifiers. Both are beautifully constructed, easy on the ears, and “do” space beautifully; in short, eminently enjoyable. Both convey the musical nature of a performance, but just do so with slightly different emphasis. Whereas the KR VA880 focuses on tonal accuracy and palpability, the RGi60ENR goes for pace and rhythm. Another way of putting this is that the RGi60ENR emphasizes the leading edges of notes in such a way that I feel that I am always right on the edge of the performance, that I am constantly tapping my toes and playing air guitar. There’s a certain “rightness” to the flow of the notes that draws the listener into the performance much like a live event does.
On the side of the KR VA880, I felt that its relative strength was its ability to give a more lifelike sense of space around individual performers. While not as fast as the REDGUM, it adds a sense of palpability to the performance that is totally engrossing. What I mean here is that the amp makes it easier for the listener to visualize the three-dimensional space embodied by and surrounding each performer such that one gets the spatial illusion that the person is really in your company. Call it body or palpability; you get the idea of what I am talking about. I found these differences apparent when listening to all three of the discs I mentioned above. It’s not like I absolutely preferred one amp over the other in an absolute sense, but rather that I was able to focus in and enjoy each for what it best contributes to the reproduction of the actual musical event.
I’ve wondered how to best summarize my time with the KR Audio VA880 integrated amplifier. Perhaps the best complement I can pay it would be to say that if I were in the market for a KR Audio amplifier, I’d probably go for it over its larger and more expensive cousin, the Kronzilla. I don’t mean to take anything away from the Kronzilla, but at a third the price, the VA880 gives a more than healthy dose of what the Kronzilla has to offer, both in terms of sound and looks. Ultimately, my preference for the VA880 comes down to personal taste: I was totally hooked by its ability to draw me into a performance with that special sense of tube-like palpability and three-dimensionality that I mentioned earlier. Whether or not this is a distortion eliminated or reduced by the more refined Kronzilla, I can’t say; what I can emphasize is how much I enjoyed it. Isn’t that what it’s supposed to be about anyway?
Try to hear the KR VA880 at a show or in a dealer showroom, or better yet, in your own listening environment. You too might become hooked.
What a lovely integrated amplifier! I thoroughly relished my time with the KR Audio VA880.It’s a perfect example of what sonic heights a hybrid solid-state/vacuum tube design can reach. It doesn’t offer a phono stage which for some people is good because they either have one already or want to choose their own since it’s a very important part of any analog system. You could find more output options on other models, I found it nonetheless to be quite friendly and workable, never giving me any grief. If you need tape loops and HT passthroughs, this is not your choice.
The 60 watt output was strong, but owners of sub 85db sensitivity speakers who listen at 100db levels in a large room may need more. The power and gain should be fine for the vast majority of audiophiles, but you know how we preach about the importance of system matching...
Those who value tone color, texture, imaging and musicality vs. the harder edged more academic presentation will like this alot. The build quality is excellent as well. It's hefty, but not so much that you need Ray Lewis' physique to move it around and it does not have a large footprint for those who have smaller spaces. If you want to do a little tube rolling, there's not a huge armada of bottles to tend with, so cost would be low.
Is it a huge bargain? Well, it does exibit a large dose of the $18,000 monster Kronzilla. The remote is high in quality and functinality. Maybe in certain cases, “trickle down” does have some merit. It is a highly effective combination of the best attributes of tubes and solid state, while avoiding the sonic pitfalls of each.We think the VA880 is very worthy of an audition.
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