Auris Audio Fortissimo Integrated Amplifier Review

Auris Audio (website) is a somewhat new addition to the rich high-end audio tradition of the central European country of Serbia.

If that strikes you as odd, let me assure you that yes, they’ve got a robust market for high-end audio manufacturing there! There are some wonderful and well-established companies from that part of the world doing some truly amazing things in the High-End corner of our hobby. A couple of the of better-known ones immediately come to mind. One is Dayens, which has enjoyed a nice presence here in the States as a purveyor of high quality budget-priced integrated amps. Another is Trafomatic Audio. a company that builds tube amps and headphone amps of exquisite looks and quality. Yet another is Pro-Ject Audio.

Heck, I even own a little amp produced in Serbia. I put it up as one of my picks last fall as a favorite of 2017: the Vista Audio Spark. Trust me here. It’s a killer for the meager asking price of $349. The Spark is the centerpiece of my A/V system in my exercise room, so it gets a lot of use. You could even say that it works out when I do.

Back to Auris Audio…

Founded in 2013, these guys might be the new kids on the block, but they are off to an auspicious start. Checking out their webpage, one finds a plethora of products. These range from a bevy of amplifiers and preamplifiers, all the way to DACs and speakers. You can even buy a preconfigured audio system directly from the company made up wholly of Auris components. As an added bonus, all of Auris’ products are built in-house in the company’s factory. These guys are totally vertically integrated, right down to winding their own transformers.

The Fortissimo

The Auris Audio Fortissimo, reviewed here, is their top-of-the-line stereo amplifier offering. A fully integrated unit offering up three sets of unbalanced RCA inputs and a single set of balanced XLR inputs, the Auris Fortissimo makes a strong visual statement. It begs to be noticed. I will wager that if you happen to encounter one in a room loaded with gear, your eyes will leap at it. Fortissimo is a term that means “very loud” in musical vernacular, and I can attest that this amplifier is visually turning up the volume.

First off, the Auris Audio Fortissimo is physically large. It’s also heavy and about as hard to move around as my big Pass Labs X250.8 amp. Looking at it straight-on, you see a gracefully rounded-off faceplate that vaguely puts me in mind of a shelled peanut. The rear panel takes on the same profile, and the two are joined together by pretty wooden side panels that are said to absorb vibrations. The big KT-120 output tubes, two per channel, stare out at the listener through a glass plate that resembles the windshield on a Model T automobile. Whether the “windscreen” actually keeps curious cats away from the hot valves remains to be seen, at least in my house.

Completing the picture are four small input tubes (ECC99s) and the two massive enclosed output transformers located near the rear of the unit. We also have two manly looking knobs on the front panel. To the left is the selector knob, and on the right is the volume control.

A beast

The Auris Audio Fortissimo is a veritable beast as tube amps go. It puts out 100 watts per channel into both 8 and 4 ohm loads, thanks to those KT-120 output tubes operated in ultralinear pentode mode. As I saw no point in letting it run in as part of my secondary system, the Fortissimo went right to the top and into the big system. Here, it took signal directly from a Crane Song Solaris Quantum DAC, and in turn, drove my big ATC SCM 100 passive monitor speakers. Driving those big ATCs might be a challenge for many amps, but it was a walk in the park for the Auris powerhouse. I used the amp’s 8-ohm taps exclusively with the SCM 100s.

Soon after the amp is turned on, relays click, informing the listener that it’s time to get going. At initial setup, and after things have gotten warmed up a bit, the output tubes need to be biased. This is an easy task involving turning small potentiometers located just behind the tubes using a screwdriver. Don’t get too close if you don’t want to get burned though. Once adjusted, I found the tubes to retain their desired bias current nicely over the long haul.

Auris recommends a warm-up time on the order of 40 minutes or so before any serious listening is attempted, but I normally waited at least an hour.

The Auris Audio Fortissimo also lives up to its name sonically: it’s a loud sucker! Compared to my more powerful Pass Labs amp, the Fortissimo seemed to have considerably more gain. Driving my ATC speakers, I rarely had to turn the volume control up above the 9 o’clock position. Much more than that, and I was about driven out of my listening room. One downside to such gain is that it sometimes became hard to settle on a good listening volume. Given the logarithmic nature of the volume potentiometer, tiny variations result in big volume differences at the lower volume settings.

Auris Audio Fortissimo rear

Sonic performance

It was apparent from the first listen that this was an exceptional sounding amplifier.

I have frequently commented that the top tier designs in both the vacuum tube and solid-state arenas have been on something of a sonic collision course, and the Fortissimo only seems to solidify this viewpoint in my mind. This thing is not your grandaddy’s Dynaco, or even your dad’s Audio Research or VTL amp of yesteryear. Like some other excellent tube designs I have heard recently, the Auris Fortissimo preserves the very best attributes of “tube sound” while adding in bass extension and control along with solid-state-like resolving power.

My ATC speakers are meant to be tools used by recording and mastering engineers, and as such, are intentionally flat in frequency response. The upshot of this design characteristic is that they can sometimes sound a bit “dead” or harmonically dry in the traditional Hi-Fi sense. I find this characteristic to be most noticeable when listening to orchestral or other classical music. Therefore, choice of ancillary equipment, especially amplification, becomes important and personal in taste. If I get the amp/speaker mojo right, I’ll know it because I listen to and enjoy more classical music, and that’s exactly what the Auris Fortissimo has me doing.

There is no doubt that playing with the ATC speakers, the Auris Audio Fortissimo exhibits sufficient harmonic richness to keep me well engaged and listening for long periods of time. Even so, the amp never goes too far into the realm of becoming tonally viscous. Midrange resolution is preserved to the same extent as the best solid-state amplifier designs with which I am familiar, and that’s a good thing.

Auris Audio Fortissimo top plate

Specifics, specifics, specifics

Hitting the new classical selections in Qobuz has been quite rewarding of late. For instance, I’ve become quite enamored with Vivaldi’s Sonatas for Cello and Basso Continuo (Harmonia Mundi, 24/88.2 flac file, streamed via Qobuz). By way of the Auris Fortissimo/ATC combo, the cello tone is vivid, woody, and exceptionally fleet of foot. Sometimes, recorded cello can sound overly dark in tone, but not here. Detail retrieval is also quite exceptional, as I can easily hear all the ancillary noises made by the cellist, mainly breathing and an occasional sigh. Interestingly, these very human noises are distinctly separate from the cello in three-dimensional space, hanging somewhat above and in front of the instrument. My first thought upon noticing these odd sounds so spatially disjointed from the instrument was “what is that?”

This level of detail retrieval and spatial presentation is remarkable, especially given the ATC speakers’ general lack of discernment in the latter area. Such observations speak volumes about the Auris Fortissimo’s ability to cast a deep soundstage with well fleshed out and defined front-to-back layering.

In and Oud

Ramping up the fun, I decided to sample some of the wonderful music of oud specialist extraordinaire Anouar Brahem. The oud, if you didn’t know, is an ancient stringed instrument that looks much like a lute. It is used in traditional Middle Eastern folk music, and Brahem can play it like a man possessed. I was first introduced to Brahem’s playing when I picked up one of his albums on the ECM label at a local thrift shop here in backwoods Pennsylvania. Proof positive that you never know what you may discover out there!

I’ve spent a lot of time in the last day or two listening to Brahem’s latest album, Blue Maqams (ECM, 24/96 flac file, streamed via Qobuz). Although classified as jazz, I consider this music much more as traditional world music placed in a jazz setting.

Here was this really simple system, consisting of a relatively unknown professional DAC, the Auris Fortissimo amplifier, and the ATC monitors, just blowing me away. I felt the sound was really starting to gel, with the system suddenly transforming into an entity that was greater than the sum of its simple parts.

The tonal character of the oud was both sweet and pungent, depending on how Brahem wished it to be portrayed. Here, the Fortissimo placed the full body of the instrument on display before me, as if sonic nectar from above. Something special was afoot here indeed. I felt like I was suddenly getting the very best out of the ATC speakers, which had somehow eluded me before. I’ve never regretted my purchase of these expensive monitors, but I’m finally now seeing what folks who own them have been raving about.

Comparison: Bakoon Amp 41

As I wrapped up my listening to the Auris Audio Fortissimo, I pulled out the recently reviewed Bakoon Amp 41. By comparison, the Bakoon is solid state and only puts out 50 watts per channel. It is, however, a superb amplifier and quite elegant in its own right. It’s also quite expensive ($9000). The Amp 41’s strengths are its speed, pacing, and precision of tone.

While I remain thrilled and highly impressed by how well the Bakoon Amp 41 couples sonically with the ATC monitors, it was bested in several respects by the larger, more powerful Auris Fortissimo. First off, the Auris amplifier brings sheer grunt to the table, controlling the SCM100s in the lower frequencies like a true champ. Via the Bakoon, the bass was very well defined, but thin. The Fortissimo, in contrast, grabbed those woofers and dug deep. Bass control was iron-fisted, yet tonally organic and not overly damped.

The other area in which the Auris Fortissimo really strutted its stuff was in its ability to cast a lovely glow on the midrange while placing just enough harmonic flesh on the bones of the music to liven up the sound of the ATC speakers. The sound in my room suddenly went beyond “accurate” and became “pretty” without losing detail or truth of timbre. If I were to characterize the midrange of the Bakoon Amp 41 as elegant, I’d have to say that the Fortissimo took the midrange to that next level of elegance coupled with natural beauty. Ultimately, I think that these minute, but important differences in tonal structure boil down to those last vestigial differences between solid state and vacuum tube amplifier design and character. While I still contend that really good solid state and really good vacuum tube designs are sonically converging, I’m not sure that they will ultimately end up in the exact same sonic camp.

Comparison: Pass Labs X250.8

The tubed Auris Audio Fortissimo and the solid-state Pass Labs X250.8 were a closer matchup. Both amps had sufficient power to fully and expressively control the ATC SCM100 monitors. Bass was deep and fulsome, with superb control via both amps: a real toss-up. The primary audible differences of note were in the midrange, though I’m not exactly talking about night and day here. The big Pass Labs amp boasts a wonderfully full and expressive midrange in its own right. However, I sensed a bit more lively and inwardly-lit effect via the Auris amp. Perhaps those vacuum tubes doing their thing? It’s as if those midrange tones were just more “alive” or somehow “highlighted” via the Fortissimo.

Listening to recorded cello really highlighted the differences. In the Vivaldi album mentioned above, the Auris Fortissimo really let me hear into the complex sonorities of the bowed cello. While listening, I was drawn into the vibrations of the strings in resonance with a real, wooden, vibrating, varnished soundboard. On the whole, I was offered up a softly spotlighted, yet wholly organic experience that just wasn’t quite as apparent via the otherwise superb Pass Labs X250.8.

Maybe there really is some magic in those vacuum tubes that transistors won’t ever quite capture, regardless of how far solid-state technology ultimately progresses.

Parting Shots

When Jason Tavares, proprietor of Adirondack Audio and Video (presently the sole distributor and dealer of Auris Audio products in the US) contacted me to pick up the amp, I was a bit crestfallen. Jason needed the Fortissimo back so he could prepare for its demonstration at the upcoming Rocky Mountain Audio Fest. I understand, but I can still be a bit bummed. It’s my own darned fault. I had other deadlines to meet in the short time the Fortissimo was here, but I really wished I had spent more time with it. Not because I didn’t get a good bead on its sonic merits, but because I enjoyed listening to music through it so much. I suppose that’s pretty high praise for a hitherto unknown amp from an interesting company in far-away Serbia.

The Auris Fortissimo is a lovely amplifier. It’s beautiful to behold, powerful to hear, and elegant all around. I thoroughly enjoyed my time with it, and if you are in the market for such a product in the price range, I reckon you might enjoy it too. It’s a top-flight product well worth seeking out, so I’d advise you to get right to it! Oh, and tell Jason I sent you.

US Retail Price: $10,999.

Auris Audio (website).

Auris Audio Fortissimo top

Product Specification

Output power 100W RMS
Class operation A/AB
Configuration Pentode – Ultra linear
Vacuum tubes 4 x KT120, 4 x ECC99
Inputs sensitivity 1.2V
Input impedance 100kOhm
Inputs 3 x RCA/XLR
Outputs 4 & 8 Ohm
Frequency response 15Hz – 50kHz
S/N > 85dB
THD % <1% / 1W , <5% / 100W
Power supply 230V ( 110V, 115V, 220V, 240V on request)
Power consumption 300VA
Dimensions W x L x H 490 x 447 x 335mm
Weight (kg) 30