Unison Research SINFONIA Class A Integrated Stereo Tube Amplifier at Vinyl Sound Buffalo, NY USA

The SINFONIA is a dual mono Class A stereo integrated valve amplifier from Unison Research (Treviso, Italy), available at Vinyl Sound in Buffalo, NY, USA. Part of the company's classic integrated amplifier family -- alongside the Preludio and the Performance -- the SINFONIA shares its core technical approach, sonic character, and Italian aesthetic refinement with the rest of the line while offering a dedicated subwoofer output for system expansion. Using four KT88 or 6550 output tubes in a parallel single-ended ultralinear Class A configuration, the SINFONIA delivers 25 watts per channel across a frequency response of 20 Hz to 30,000 Hz, with a nominal impedance of 4-8 ohms and IR remote control for input selection and volume from the listening position.

Classic Line Aesthetic and Engineering

The SINFONIA occupies the position within Unison Research's classic integrated amplifier range where sonic performance, visual elegance, and practical reliability converge. Its parallel single-ended ultralinear Class A output stage uses four KT88 or 6550 output tubes -- among the most widely respected audio output pentodes -- with a feedback factor of 14 dB for frequency stability, and ECC82 and ECC83 support tubes handling the preamplifier and driver stages. A 2015 review in Fidelity Magazine noted the exceptional build quality of the Sinfonia LE Anniversary (a limited commemorative variant), comparing its design sensibility to that of classic Italian craftsmanship in its combination of curved lines, fine materials, and structural precision. The standard SINFONIA shares this foundation of material and aesthetic integrity. Power consumption of 500 watts maximum reflects the thermal demands of continuous Class A bias across four output tubes.

Connectivity, Remote Control, and Subwoofer Integration

The SINFONIA provides four RCA line inputs and one tape input for source selection, one tape output for recording, and a dedicated subwoofer output for integration with a powered bass supplement. The subwoofer output is active, meaning it carries a full-range signal that the connected subwoofer's internal crossover processes to extract the low frequencies relevant to the sub's driver. IR remote control governs both input selection and volume adjustment, making the SINFONIA practical in larger rooms where manual front-panel operation is inconvenient. The output section provides 4-ohm and 8-ohm taps with bi-wiring capability, ensuring compatibility with a broad range of loudspeaker nominal impedances. Dimensions of 17.3 x 16.5 x 8.3 inches and a weight of 55 lbs position the SINFONIA as the most compact dual mono Class A integrated in the Unison Research classic range.

Key Features

• 25 W/Channel Parallel Ultralinear Class A: Four KT88 or 6550 output tubes in a dual mono configuration deliver 25 watts per channel in pure Class A without crossover distortion.
• Dual Mono Architecture: Independent left and right channel signal paths minimize crosstalk and preserve stereo separation.
• IR Remote Control: Governs both input selection and volume from the listening position.
• Dedicated Subwoofer Output: An active subwoofer output enables integration with a powered bass supplement for extended low-frequency performance.
• 4-Ohm and 8-Ohm Output Taps: Bi-wiring capable output terminals provide impedance matching flexibility for a wide range of loudspeakers.
• Classic Line Reliability: Unison Research's classic line is designed with long-term reliability as a primary objective, using proven circuit topologies and high-quality materials throughout.
• Italian Craftsmanship: Designed and manufactured in Treviso, Italy, with the visual refinement and material quality characteristic of all Unison Research products.

Technical Specifications

Frequently Asked Questions

What is the Unison Research SINFONIA?

The Unison Research SINFONIA is a dual mono Class A integrated valve amplifier from Treviso, Italy, producing 25 watts per channel through four KT88 or 6550 output tubes in a parallel single-ended ultralinear output stage. It provides four line inputs, one tape loop, a subwoofer output, IR remote control, and bi-wiring speaker outputs across a frequency response of 20 to 30,000 Hz.

How does the SINFONIA compare to the Unison Research Performance Anniversary?

The SINFONIA and Performance Anniversary share the same dual mono Class A ultralinear output topology and tube families (KT88/6550, ECC82, ECC83), but differ in output power and specification. The SINFONIA produces 25 watts per channel, while the Performance Anniversary produces 45 watts using six (versus four) output tubes. The Performance Anniversary uses Gold Lion output tubes as a factory-fitted specification and has a higher feedback factor (16 dB vs 14 dB). Both offer IR remote control, but the SINFONIA's smaller dimensions (17.3 x 16.5 x 8.3 inches vs 23.6 x 18.9 x 9.3 inches) and lower weight (55 lbs vs 110 lbs) make it the more compact option for smaller listening rooms.

What is ultralinear mode in the SINFONIA's output stage?

Ultralinear is an output stage configuration in which the screen grids of pentode output tubes (such as KT88 or 6550) are connected to intermediate taps on the output transformer's primary winding rather than to a fixed supply voltage. This arrangement partially applies the output transformer's feedback to the screen grid, linearizing the tube's transfer characteristic and reducing distortion relative to pure pentode operation, while preserving more output power than full triode mode. In the SINFONIA, the ultralinear topology in a single-ended parallel Class A configuration strikes a balance between the harmonic richness associated with triode output and the power efficiency of pentode operation.

Can the SINFONIA be used with a subwoofer?

Yes. The SINFONIA includes a dedicated active subwoofer output that carries a full-range line-level signal. Any powered subwoofer with an RCA line input and internal crossover -- such as models from SVS, REL, or JL Audio -- can be connected to this output. The subwoofer's internal crossover determines the low-pass frequency applied to its driver, while the SINFONIA's main outputs drive the loudspeakers full-range without any high-pass filtering imposed by the amplifier.

What loudspeakers work well with the SINFONIA?

The SINFONIA's 25 watts per channel in Class A is well suited to loudspeakers of 89 dB sensitivity or higher. The Unison Research MAX 2 (96 dB), MAX 1 (94 dB), MAX MINI (93 dB), and MALIBRAN (89 dB) are all compatible partners within the brand. High-efficiency loudspeakers from Klipsch (Heritage series), DeVore Fidelity, and similar manufacturers also pair naturally with 25-watt Class A valve amplifiers.

Where can I buy the Unison Research SINFONIA in Buffalo, NY or the USA?

The Unison Research SINFONIA is available at Vinyl Sound in Buffalo, NY, USA. Vinyl Sound is an authorized Unison Research dealer serving customers across western New York and the wider United States. Contact Vinyl Sound to confirm current availability and to arrange a listening demonstration.