The Anniversary edition of the Unison Research Sinfonia isn’t just a masterpiece of Italian design—it also happens to have quite a bit in common with the legendary Riva boats. Both are powered by eight cylinders, which unleash their energy from within a refined mahogany shell. Granted, the Sinfonia tube amplifier doesn’t cut through the waves of Lake Iseo with its elegant mahogany hull—but it does delight us with the finest soundwaves.
According to the Unison Research website, “We firmly believe a Hi-Fi system should not only sound great but also be visually appealing.” This company philosophy has played a huge role in shaping my perception of Italian high-end audio. Sure, there are many ways to achieve this blend of form and function, but I’ve always felt our neighbors to the south have a unique knack for it. The Unison Research Sinfonia LE Anniversary, released in 2012 for Unison Research’s 25th anniversary, is a prime example of this philosophy. The moment I laid eyes on it, it reminded me of the iconic Riva boats—the preferred leisure vessels of the rich and famous in the 1950s. Gracefully curved lines, meticulously finished mahogany, and classy metal fittings define both the sought-after (and insanely expensive) speedboats and the Sinfonia LE.
This macchina musicale could serve purely as a sculpture in my living room. But that would be a shame. Running my fingers across the flawless finish of the solid Sapelli mahogany casing was a joy. And when I first touched the generously sized, machined stainless-steel knobs, I thought: This is exactly how it should feel—like stone eggs, but made of metal. Depending on the function, the tactile response varies between a silky-smooth resistance or a satisfying mechanical “click.” Perfetto!
But enough gushing—let’s talk about what’s inside. The Sinfonia Limited Edition Anniversary is an all-tube integrated amplifier delivering 27 watts per channel in pure Class-A operation. Each channel uses two Genalex Gold Lion KT88s in a single-ended, parallel/ultralinear configuration. These tubes sit in gold-plated sockets. The input stage uses ECC82s, while ECC83s drive the output stage—also premium Genalex tubes. All tubes are matched and hand-selected. High-quality Mundorf capacitors are used throughout the signal path. To ensure complete channel separation, the circuitry is designed in dual-mono architecture. The center transformer block contains two stacked toroidal transformers that provide independent power to each channel.
Visually, the Sinfonia LE distinguishes itself from the original 2005 Sinfonia with its mahogany casing and copper, rather than aluminum, heat shields.
Michael Wiesler from TAD Audiovertrieb, the official distributor of Unison Research products, explained to me that the company continuously improves its products over time. To dive deeper, I contacted Alessio Fusaro from the R&D team, who kindly answered my questions—even while on vacation. He explained that the copper coating on the circuit boards was increased from the original 35 microns to 70, and in some cases up to 105 microns. The layout has been continuously optimized, and the output transformers are now in their third generation. Larger, electromagnetically shielded transformers are now used. The two toroidal transformers are positioned in opposite orientations to cancel out stray electromagnetic fields and transformer hum—a method that worked flawlessly during testing. The amp was whisper-quiet.
When I asked about the expected lifespan of the output tubes, he said the amp doesn’t drive the KT88s too hard, achieving up to 2,000 or even 2,500 hours before performance begins to drop. An automatic biasing system ensures each tube is optimally driven throughout its lifespan. During final testing, all tubes are calibrated and matched for channel balance and frequency response. Fusaro also emphasized that most suppliers are local to maintain consistent quality.
“Tube rolling” is not recommended, as the Sinfonia LE is specifically tuned to the Gold Lion tubes. I don’t see this as a downside—it ensures perfect synergy. Michael Kaim, managing director of BTB Elektronik Vertriebs GmbH, and a true authority on tubes, also considers the Gold Lion KT88s an excellent match for this amp.
The Sinfonia’s feature set is elegantly minimalist. It offers four RCA inputs, a tape loop, double speaker terminals for 4- or 8-ohm configurations, and a power socket on the back. There’s also a dedicated jack to power the Unison Research Simply Phono, eliminating the need for a separate power supply.
I was especially pleased to see true bi-wiring capability—my 2 x 2 Kimber 8TC cables connected effortlessly. The previously mentioned stainless-steel knobs protrude from the mahogany front panel: one for power, one for volume, one for input selection, and one to activate the tape monitor. Volume and input selection are also controllable via the stylish remote—crafted from wood and metal to match the amp, far superior to the typical plastic remotes. The automatic bias feature is another convenience—each tube’s idle current is adjusted automatically at startup. This takes about five seconds.
There’s no built-in phono preamp or DAC, which I believe is the right call. Anyone investing in a piece like this will likely want high-end external components anyway—why compromise with built-in “convenience” features?
Tube amps get hot—especially Class A designs. So, onto the top shelf of the rack it goes. And honestly, who’d want to hide the seductive looks of this amplificatore a valvole in a cabinet anyway?
I chose the 4-ohm speaker taps since my Audio Physic Spark speakers dip to 3.2 ohms. Testing confirmed my instinct—the 8-ohm taps drained some of the life from the sound. Despite their modest 88 dB/2.83 V sensitivity, the speakers had no problem filling my roughly 260 sq. ft. (24 m²) listening room. I rarely had to go beyond 10 o’clock on the volume dial.
Then came the sacred ritual: installing the tubes. Wearing white cotton gloves (fingerprints on glass are a no-go), I matched each numbered tube to its designated socket using the diagrams on the transformer covers. Because the tubes are precisely matched pairs, this arrangement is essential. A steady hand and gentle touch are key…
Then came the moment of truth. With a satisfyingly solid click, I flipped the power switch. All four LEDs on the input selector lit up for five seconds. The tubes glowed to life with a warm, soft light. I slowly turned up the volume… and heard nothing. No hum, no hiss, no pops—just silence. Glorious silence.
Though Wiesler assured me this unit was fully broken in, I still ran it gently for the first few days. In my experience, even review units need a bit of acclimatization before they reach their full potential.
Now, the million-dollar question: How does it sound? Could it live up to my high expectations after such a flawless showing? Maybe even surpass them?
From the very first notes, the Sinfonia LE projected the music into the room with stunning presence—completely detached from the speakers, as if the system had nothing to do with producing this beauty. It felt real. So real that I just kept playing record after record, not even thinking about analyzing the sound.
Johann Christian Schieferdecker’s Musicalische Concerte (Hamburg, 1713), performed by the Elbipolis Baroque Orchestra and recorded in 2011 in a church in Gütersloh, was a standout. The unusual instrumentation (theorbo, various percussion) and the natural acoustics were rendered with astonishing precision. Many good amps can do this—but the effortless, natural ease with which the Sinfonia presented the performance was extraordinary. The sound felt reverent, spiritual even.
Tonal hues, dynamic shifts—everything came through in vivid detail, without drawing attention to any single element. Nearly every album I played benefited from this capability.
To test modern genres, I put on Cure, the debut album by Eddy de Pretto. The deep synth lines and fat drumbeats were handled effortlessly by the 27 Class-A watts. De Pretto is often compared to Jacques Brel in France—which may be a stretch, but the general direction makes sense. The Sinfonia LE made that clear.
Any suspicion that the amp might “sweeten” the sound evaporated as soon as I dropped the needle on Carlos Santana & Buddy Miles! Live! (1972 vinyl). It sounded just like most live rock recordings from that era—flat, midrange-heavy, and muddy. Off it went, and I returned to more pleasant listening, well into the night.
The Sinfonia Limited Edition Anniversary could easily be the centerpiece of a high-end system that leaves nothing to be desired. It’s like a truly great wine—free of excess, full of subtle complexity, and long-lasting in the finish. It takes a certain level of experience to fully appreciate. Maybe the Unison team’s passion for fine wines played a role—company head Bartolomeo Nasta is a trained sommelier.
Any doubts I had about the amp’s “modest” power rating were completely unfounded. Maybe it’s not for fans of earth-shattering techno or heavy metal. But with the right speakers (15” drivers, horns, consistent impedance – Unison themselves offer suitable candidates) it’ll handle that, too.
In the world of high-end audio, value is often hard to define. But here—when you consider the craftsmanship, the materials, the fact it’s made in Italy, and most of all, the sound—calling this a fantastic value feels almost like an understatement.
Accompanying Equipment
Turntable: TW Acustic Raven GT2 | Tonearms: TW Acustic Raven 10.5” & 9.5” | Cartridges: Skyanalog Reference, Clearaudio Concerto V2, Excalibur Platinum | CD Player: Electrocompaniet EMC 1 MKV | Amps: Electrocompaniet EC 4.8, EC AW250R, Lab 12 Melto2 | Speakers: Audio Physic Spark on Solidsteel SS-5 | Power & Cables: IsoTek, AudioQuest, Zavfino, Kimber, WBT | Accessories: bFly-audio, Audio Physic VCF Magnetic, Lehmannaudio, Nessie, Sonic Voice
Tube Integrated Amplifier Unison Research Sinfonia Limited Edition Anniversary
Output power: 2 x 27 W | Tubes: 4 x KT88, 2 x ECC82, 2 x ECC83 (all Genalex Gold Lion, specially selected) | Highlights: automatic bias, Mundorf capacitors in the signal path, copper heat shields | Dimensions (W/H/D): 15.75 x 7.7 x 15.2 in (40 x 19.5 x 38.5 cm) | Weight: 55 lbs (25 kg) | Included: IR remote, power cable, user manual | Finish: Cherry or Mahogany | Price: approx. €6,599
TAD
Hallwanger Straße 14
83209 Prien am Chiemsee, Germany
Phone: +49 8052 9573273 or +49 9941 9084210
Email: hifi@tad-audiovertrieb.de
www.tad-audiovertrieb.de