Note that this is a discontinued product. You may want to visit the brand's page here to browse their newer products.
What reviewers think
Bloggers and YouTubers have tried this product—so we've summarized their strongest opinions below. Links to full reviews follow.
All
Absolute 845 SE
reviews
Manufacturer details
- Type: Dual mono Stereo Integrated Valve Amplifier
- Output Power: 40 watt / channel
- Output Impedance: 4 – 8 Ohm
- Inputs: 5 line, 2 tape
- Input Impedance: 47 kOhm
- Outputs: 2 tape, loudspeakers bi-wiring
- Feedback factor: 10 dB
- Frequency Response: 20 Hz – 30 kHz
- Valves: 4 x 845, 6 x ECC82, 2 x ECC83
- Power Consumption: 700 VA
- Dimensions: 31.7 x 23.8 x 11 inches
- Weight: 199 lbs
Brand highlights
Taking a step back to look at reviewers' thoughts of the brand's entire lineup—not just this product—what stands out most is the following:
- Unison Research products are hand-crafted in Italy, using locally sourced materials and distinctive design elements like wood trim and stainless steel, creating a unique visual aesthetic.
- They specialize in hybrid amplifier designs, using tubes in the preamp stage and solid-state MOSFETs in the output stage, aiming to capture the sonic benefits of both technologies.
- They custom-design and manufacture their own transformers, tailoring them to specific amplifier models for optimal performance and a unique sonic signature.
- Unison Research designs incorporate minimal stages and often utilize zero feedback, prioritizing sonic purity and a balanced sound across a wide range of music genres.
Select products
Simply Italy
- Positioning: The entry-level integrated amplifier in the Unison Research lineup.
- Description: Offers a compact design with a focus on delivering high-quality sound through its single-ended, ultralinear Class-A output stage. It stands out with its optional USB DAC board, making it versatile for digital audio sources, unlike the more traditional analog-only models like the S6.
Unico Primo
- Positioning: A mid-range integrated amplifier in the Unison Research lineup, offering a balance of performance and affordability.
- Description: Features elegant design and robust build, with a Dynamic A Class POWER MOSFET output stage. Its multiple RCA inputs, including an optional phono stage, offer greater system compatibility compared to the more basic Simply Italy.
Triode 25
- Positioning: A versatile mid-to-high range amplifier, celebrating Unison Research's 25th anniversary with advanced features.
- Description: Notable for its ability to switch between triode and pentode modes, offering flexibility in sound output. Its dual-mode operation and higher power output provide enhanced versatility.
Performance
- Positioning: A premium offering, designed for those seeking high power and classic design.
- Description: Delivers 45 watts per channel with a dual mono design, providing a powerful and immersive audio experience. It surpasses the S6 in power. Its bi-wiring capability and elegant design enhance its functionality.
Reference
- Positioning: The flagship monoblock amplifiers in the Unison Research lineup, offering the highest level of performance.
- Description: Designed for ultimate power and precision, featuring a double parallel single-ended Class-A design. With 80 watts of output power, they exceed the Performance model. Their superior build and advanced technology represent the pinnacle of the lineup.
Our take on the brand
Look inside the brand
Our interview with the brand
What are two key technological innovations or strong opinions that differ you from other brands?
We’re an Italian company that sources everything as locally as possible. Italian through and through—everything we do is done here in Italy. Italian gear really does have its own sound. Sounds more romantic, less analytical. Very listenable. Low levels of ear fatigue.
We’re still hand making tube amps and continually refining them. New innovations in grounding, such as each component being grounded independently so they're really quiet as far as tube amps go, is an ongoing focus—always evolving mature tech.
But we also have new modern tech that's a hybrid of solid state and tube—to give you the best of both worlds. You can run pretty much any speaker you want.
In short, it’s a really easy to listen to sound.
What's your approach to customer support?
What are your favorite tracks for showcasing the strength of your products?
What other products pair best with yours?
Opera speakers are a great pairing because they're under the same parent company . When Unison is voicing their amps, they use Opera speakers, and vice versa.
However we've had no issues with pairing with Unison research. (But if you're looking at tube gear, you do have to be more careful because you do need a more sensitive speaker.)
In fact, are your speakers very technical? Pairing with Unison Research can help tame that a bit.
Used
Unison Research
What if you spend more?
Audio Phonique PSE1605 mono amplifiers will take you to the world of limitless space full of dynamic vibrant sound sources and associated extremely high emotional content. If being as close to live music as possible is what you’re after, then our luxurious and unique PSE1605 mono amplifiers will get you there.
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Product Strengths
- High momentum, dynamic span, effortlessness, and immediacy.
- Open and highly complex spatial frames with loads of air around sound sources, filled with colors securing a zesty, vibrant, moisturized, and articulated view.
- A unique blend of virtues—posh, elegant, euphonic, organic, fresh, and engaging—while showing detail and clarity.
Product Considerations
- Very hot and needs enough space for heat dissipation.
- The shiny chassis attracts dust and fingerprints and requires regular cleaning.
- Elongated narrow enclosures require deeper than usual shelves or floor placement.
- The review unit had an inactive balanced socket that paying customers won't see.
Comparisons (according to reviewers)
- Vs Trilogy 995R: Bass is shallower and not as beefy, but more elastic and complements the higher ranges instead of dominating.
- Vs Aavik I-880: PSE1605 trades some quickness for extra tone.
- Vs Enleum AMP-23R, Nagra Classic-INT, and AGD Production Vivace monos: PSE1605 trades some of its quickness and illumination for more tone and grounded perspective, but still scores very high on detail and clarity.
Takeaway: The Audio Phonique PSE1605 mono amps offer a unique listening experience with exceptional sound and a vibrant soundstage. If one appreciates a combination of elegance, detail, and engaging sound, the PSE1605 could be a great fit.
Video review
Our take on the brand
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Since its introduction in 2022, Apex has been hailed as the finest power amplifier ever created. Critics and connoisseurs have universally praised its combination of shattering power and sublime delicacy; its ability to drive any loudspeaker balanced with unimpeachable tonal neutrality. It has always been Gryphon’s mission to achieve the highest possible audio performance in terms of sheer musicality, transparency and realism. With Apex Mono and Apex Stereo, Gryphon Audio Designs has elevated pure Class A power amplification a titanic leap above what was previously considered possible. Gryphon Apex takes us several significant steps closer in the quest for the most natural and convincing musical illusion.
Product Strengths
- Delivers lots of current due to a new 2000VA toroidal transformer
- The Apex Stereo's ease of presentation was immediately obvious—it fully engaged the reviewer
- The amp exuded supreme self-confidence
- The amp simultaneously speeds things up and slows things down
- Superior speaker grip, improving organization, timing, and musical flow
Product Considerations
- Initial start-up can be alarming due to flashing error lights
- The size and weight (445 lbs) can make installation challenging
- It's gigantic and heavy, requiring special equipment and tools to handle its production
Comparisons (according to reviewers)
- Vs Boulder 2060: The Apex revealed more tonally saturated sounds
- Vs Boulder 2060: Apex cast a larger soundstage, and within those huge spaces, images were generally larger and more three-dimensional
- Vs Boulder 2060: Apex exposed more detail in the music
Takeaway: The Gryphon Apex Stereo is a powerful amplifier that brings music to life with a balanced and full sound at any volume. Its ability to reveal the resonant nature of instruments transforms listening sessions into immersive experiences.
Video review
Our take on the brand
The company's inaugural creation, the Momentum Mono Amplifier, served as the foundation for its product line. The Momentum M400 MxV Mono Amplifier, the latest iteration, enhances the iconic design to new heights. Incorporating techniques and topologies from the Relentless Mono Amplifier, the Momentum M400 MxV models represent the pinnacle of Momentum circuitry evolution. The new model name, MxV, signifies Mass times Velocity—the fundamental equation for Momentum, a recognition that resonates particularly with individuals having a physics background. Explore the cutting-edge Momentum M400 MxV for an unparalleled audio experience.
Our summary
Product Strengths
- Exquisite aesthetics with a sleek design and a power meter that glows green
- Delivers a smooth and satisfying sound
- The sound is described as 'louder' and more powerful
- Said to be able to drive any speaker to its maximum output
- Upgrades are retrofittable to earlier Momentum models
- Balanced input only
Product Considerations
- Runs warm
- The scale on the power meter is essentially uncalibrated
- Requires a return to the factory for MxV upgrades on earlier Momentum Models
Comparisons (according to reviewers)
- The Momentum M400 MxV incorporates technology from the Relentless line and gets very close to the Relentless sound regarding space and depth
- The Momentum M400 MxV is smaller and lighter than the Karan Acoustics POWERa mono
- The Momentum M400 MxV is smaller and lighter than the D'Agostino Progression M550 Mono amplifier
Takeaway: The Momentum M400 MxV monoblock is a beautifully designed and powerful amplifier that delivers a smooth and satisfying listening experience. It incorporates technology from the flagship Relentless model, making it a top-tier choice for audiophiles.
Video review
Our take on the brand
Product Strengths
- Fully balanced design, handcrafted in the USA
- Employs a sextet of KT170 valves, ECC83, and 6H30, with hand-selected and matched valves
- Features Audio Research's 'Auto-Bias' circuitry and an internal hour meter for monitoring valve usage
- Aesthetically elegant design with unique 'Ghost Meters' which are LED-illuminated and can be dimmed or switched off
- Capable of delivering high power at low frequencies, controlling and driving speakers like a big solid-state amplifier
Product Considerations
- High price point
- Requires a 20A IEC cable (supplied)
- The bass control and sheer bass output of the Gryphon Audio Antileon EVO (solid state) could not quite be matched by the Reference 330M
- The unit use a variable speed fan, although it was essentially silent during testing, this may still present a point of concern for some users
Comparisons (according to reviewers)
- Vs Gryphon Audio Antileon EVO: The Gryphon Audio Antileon EVO (solid state) has slightly better bass control and output
Takeaway: The Audio Research Reference 330M is an intelligently engineered and beautifully styled amplifier that embodies the meaning of 'Reference' in sound quality. Its powerful valve design delivers excellent performance and is sure to be a conversation piece in any high-end audio setup.
Video review
Our take on the brand
What competes at this price?
Our Summary
Product Strengths
- Visually stylish, luxurious, well-built, and enjoyable to look at
- Offers extensive functionality including preamp gain adjustment, channel balance, mute, and display brightness settings
- Combines qualities of both tube and transistor designs, having transparency and magical realism with easy power
- Produces a clean, succinct, holographic, and exciting sound, with great dynamic capabilities
- Exceptionally well-balanced frequency response, fitting between the warmth and energetic explicitness of other amps
Product Considerations
- Massive and heavy, making it not easy to move around
- Single ended inputs only with no balanced inputs
- The vast disparity between the damping factors—synergy can vary with speakers
Comparisons (according to reviewers)
- Aavik I-880 was leaner, more illuminated, outlined and energized, spatially grander, less intimate and occupied via shorter key sound sources, compared to Trilogy 915R preamp and twin 995R mono amps
- The I-880 was internally juicy, admirably outlined, enjoyably angry, instantaneous, and powerful in the lower end range, where the twin 995Rs were boomier, fuzzier, slower and sensibly shallower on the very bottom
Takeaway: The Aavik I-880 is a high-performing, visually stunning integrated amplifier that brings music to life with both elegance and power. This amplifier is designed to be a centerpiece, both sonically and aesthetically, in any high-end audio system.
Video review
Our take on the brand
Our Summary
Product Strengths
- Strong physical presence and handsome aesthetics, featuring lacquered copper heatsinks, venturi tunnels, and Breguet-style dials.
- MxV upgrades bring significant improvements in core music reproduction areas such as sound stage, detail, and dynamics.
- The Momentum M400MxV sounds 'louder' and more powerful even when set to the same levels as its predecessors.
- The Momentum MxV amplifiers have the ability to bring out the best in loudspeakers
Product Considerations
- The D'Agostino Momentum MxV monoblock is a heavy piece of equipment, weighing 43kg apiece without optional stands.
- The Momentum M400MxV may run warm
- DIP switches for input loading are inside the unit, which requires removing the top cover when switching between cartridges
Comparisons (according to reviewers)
- The Momentum MxV amplifiers bring much of what inspired the larger Relentless Epic 800 and Relentless Epic 1600 to a smaller form factor and price point
- The early Momentum Stereo delivered around half the power of the monoblocks, compared to the Momentum Stereo.
Takeaway: The D'Agostino Momentum MxV amplifiers bring high-end performance in a visually striking package, capable of significantly enhancing the listening experience through improved detail and dynamics. The upgrade path for existing owners also makes it a worthwhile long-term investment.
Video review
Our take on the brand
Our Summary
Product Strengths
- Employs Pathos InPoL Technology/Dual InPoL Circuit, aiming for Pure Class A amplification and a warm, natural sound
- Delivers substantial power: 100 watts per channel into 8 ohms, and 170 watts per channel into 4 ohms
- Uses high-quality components and a power supply based on 1,800 VA toroidal transformers per channel
- Features a tube preamp (using Tun-Sol ECC803 and 6H30 Sovtek tubes) and MOSFETs in the power amplifier
Product Considerations
- The amplifier is large (540 x 800 x 300 mm) and very heavy (100 kg), possibly making it difficult to integrate into standard hifi setups
Takeaway: The InPoL is engineered to deliver a natural sound and substantial power, using high-quality components and a sophisticated design. This could be a compelling option for individuals seeking a high-end amplifier.
Video review
Our take on the brand
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Our Summary
Product Strengths
- Refined and powerful sound that can compete with the best
- Big and authoritative sound, dynamics, and deep bass
- Natural and lifelike midrange, and a treble that's so extended that it allows you to find the magic in hi-rez digital
- Enormous soundstage in all directions
- Able to play loud without strain, distortion, or compression
- Offers a refined and powerful sound that can compete with the best
- Big and authoritative sound, dynamics, and deep bass
- Able to play loud without strain, distortion, or compression
Product Considerations
- The power receptacle is 20 amps, and a suitable power cord was not included
- Large and heavy amplifier weighing 55 kilos without packing material, so placement needs consideration
Comparisons (according to reviewers)
- Vs Burmester 909 and 088, the True Life Audio TSI-300 did not make singers ten feet tall, like some big systems do, but there was a stronger sense of the sound going far beyond the room boundaries, while the Burmester gear had an unexpected talent for keeping the images and the soundstage confined to a realistic, lifelike size
Takeaway: The True Life Audio TSI-300 seems to do everything it needs to do without compromise, delivering drama and raw emotion. It will appeal to those who love a big and authoritative sound, dynamics, and deep deep bass without sacrificing musicality.
Video review
Our take on the brand
Our Summary
Product Strengths
- The Brama's graceful sound, looks, fit, finish, and feel make it a standout as a complete package, delivering the sonic goods.
- The Brama offers a finely resolved ease to the sound that does not trade resolution for warmth, but rather offers grace and delicacy.
- It is a completely clean, clear silent runner, with absolutely no discernible self-generated interference.
- The Brama's greatest appeal lies in presenting music as a door already open, without obstruction caused by perceived sonic shortcomings.
- It is a master at fluidity, richness without ever sounding overripe, and dynamic impact that feels right as opposed to overcooked.
Product Considerations
- The control knobs get warm to the touch, but that is just aluminum doing its heat dissipation thing.
Comparisons (according to reviewers)
- Using the Brama's pre-out as pre, the Riviera monoblocks turned the rich cornucopia of sounds into a more believably dense and dimensional garden as compared to the Brama as integrated amp.
Takeaway: The Vinnie Rossi Brama Integrated Amplifier offers graceful sound and attractive design, making it a compelling choice. Its effortless purity and full-range reach invite the listener into the music.
Video review
Our take on the brand
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