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.
Product Strengths
- Wide and deep soundstage, with a depth extending as far as 70 feet in one test
- Music reproduction is natural and realistic, creating a sense of instruments and voices being present in the room
- High frequencies and cymbals shimmer and crash realistically
- Impeccably constructed and manufactured with original circuit solutions
- Capable of drama, delicacy, and danger which transcends reproduction — turning the act of listening into a full-fledged experience
Product Considerations
- Selector knob on top of the unit is difficult to access when the tube cage is installed
- Speakers need to be a good match for the amplifier's 23 watts of power
- Bass was shy and ill-defined when used with the Dynaudio Contour 60i speakers
Comparisons (according to reviewers)
- Compared to Conrad Johnson Premier 10 & 11A, the Simply 845 has a wider and deeper soundstage and better reproduction of high frequencies and cymbals
- Compared to PrimaLuna (top-of-the-line), the Simply 845 sounds better sonically
- Compared to Line Magnetic Audio LM-845iA Integrated Amp, the Simply 845 does delicate better
Takeaway: The Simply 845 is a revealing integrated amplifier that makes music sound magical and is an excellent choice, especially for horn speaker lovers. This amplifier transforms speakers into something wonderful and will enhance the music experience.
All
Simply 845
reviews
Manufacturer details
- Type: Integrated tube amplifier
- Tubes: 2 x 845 selected, 4 x ECC82/12AU7 selected
- Maximum power: 23W
- Bandwidth: 20Hz-50kHz, +0dB; -1dB @ 12W
- Feedback level: 14 dB
- Output impedance: 6 Ω
- Input impedance: 47 kΩ/100pF
- Inputs: 4 line level
- Outputs: 1 tape, 1 subwoofer
- Power consumption: 300VA
- S/N: 120db
- THD: <0.002%
- Dimensions (LxHxD): 37 cm x 26cm x 57 cm (14 1/2 x 10 1/4 x 22 1/2 inch)
- Weight: 30,5 kg (67 lbs)
- Mains fuses: 5x20mm – 6.3 AT 100V-120V, 5x20mm – 3.15 AT 220V-240V
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?
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With the inclusion the new tube cage, the transformer cover was raised 2" to allow the cage to fully protect any KT-120/KT-150 tube. The resulting metal work and power supply changes have yielded our quietest Nautilus yet. Many still love the sleek lower profile look of the Classic Nautilus and as such we allow you to order your Nautiluswith the original metal work style or the Rev 2. The Classic Nautilus will additionally save you $1000 on the purchase.
The Story of the Nautilus is born of the same process that brought the Zions. We set out to build my private amps apart from ampsandsound. These were to be mine without branding and never to leave for demos. All too often, my own listening space was sacrificed for the need for demo stock. I chose the HK Cit II as my inspiration point. From that seed came my own Cit II Monos build on turrets just like the best amps of the golden age.
The Nautilus brings the dual-mono layout onto a single chassis. We started with our most versatile circuit, the Mogwai, and went about creating two separate amps that share a single chassis. 2 Power Transformers, Separate Power Supplies, Chokes, and input transformers. The amps are built with separate turret boards, with the shared component being the input tube, volume control, and outputs.
The Nautilus is a classic and decidedly prosaic design, as it employs turrets and point-to-point wiring & there is no silicone, ICs, or regulators. We consider this a standard-bearer of purest audio with an American sensibility. The Nautilus is built in a way few modern amplifiers are. This is not due to intrinsic inferiority, but rather it is impossible to rush and is incredibly expensive to produce.
The Nautilus has been described as a tube integrated amp for personal audio users. We mean by this, the Nautilus allows for five separate impedances to be selected for system matching and has a pair of 8ohm 5 way binding posts. The speaker vs. headphone output is selected with a small toggle switch on the back of the amp.
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Product Strengths
- Five individualized outputs with different impedances
- Custom wound ultra-high quality output transformers provide excellent frequency extension and a flat response
- Engaging audio components offer superior sound quality using proven theories, solid engineering, and quality manufacturing, all taking place in the USA
- Brings out the very best qualities in all of the headphones tested, providing the best presentation ever heard from the Aeolus
- Build quality is a step-up from other amplifiers
Product Considerations
- The most expensive quarter inch plugs you can get, have locks on them, which can be annoying
- Unplug headphones before switching to speaker outputs
- Weighs around 68 pounds and around 93 pounds shipped in its large pelican style case—it is heavy
- Can clip when used with speakers if pushed too hard
Comparisons (according to reviewers)
- Nautilus sounds better than the ZMF Pendant Headphone Tube Amplifier and the Mogwai OG Tube Amplifier in every regard
- Nautilus is even more comprehensive and expressive through the powerful, well-controlled, tonal density that is detailed and rich in nuance—it has more extension and top-notch resolution
Takeaway: The Nautilus seems to be a versatile amplifier that brings out the best in headphones and speakers. It's built with quality parts and offers a lush and detailed sound experience for audiophiles who want to enjoy music to the fullest.
Video review
Our take on the brand
Double the Performance Trouble-free, noise-free, and double the power of traditional 300B amps. Made possible by patented circuit design. A New Classic We’re proud to continue a legacy of quality, American manufacturing with innovative new features. Ships with Tubes The 91E ships with new production 300Bs, the most popular electron tubes in the world. Made in the USA.
Product Strengths
- New patented design SCS (source current steering) allows the amplifier to have a fabulous bottom end without affecting the glorious midrange
- Proprietary noise reduction system eliminates noise that can be inherent in a single-ended design
- Circuit protects the 300Bs and keeps them in their safe operating range, so there is no chance of damaging the tube or having a shortened life
- More power from this amp than a traditional 300B, it's the difference in presentation
- It has Bluetooth, phono stage (moving coil and moving magnet), and wireless remote control
Product Considerations
- Instructions could be a little clearer about installing the 300Bs
- More warm-up is needed for each listening session than originally allowed
- The 91E was designed for operation with Western Electric manufactured 300B electron tubes
- The brands and specifications of the capacitors, resistors, transformers, internal wires, RCA jacks, switches, and binding posts are not disclosed
Comparisons (according to reviewers)
- Vs WE 91A: 91E retains what's best about the early WE 91A—its delicacy, bloom, openness, and tonal magic—and adds modern improvements
Takeaway: The Western Electric 91E is a uniquely designed amplifier providing great sound with modern features like Bluetooth and remote control, pushing what a 300B tube amplifier can achieve. It's a great option for audiophiles wanting to step up from other tube amplifier sounds.
Video review
Our take on the brand
In the world of audiophiles, there is purist group militating for simplicity in tube amplification systems focusing on the use of the tube designed in the early days of tube technology: the directly heated triodes of which the most famous is the 300B. I300 is built around a simple 300B push-pull without feedback which offers unequalled musiciality of this tube.
After the preamplification using an ECC82, the signal feeds a phase inverter (called Schmitt) followed by 6SN7 triodes sufficient to drive the 300B.
The power supply is another strong point. In addition to the fact that each stage has its own power supply, particular care has been taken with the 300Bs themselves.
As direct heated triodes, the heater is the cathode. This requires a very "clean" power supply with no less than seven separate power circuits.
As for all our devices, transformers are designed and manufactured in our workshop. The one dedicated to the power supply, uses a magnetic circuit EI M6X of a design which gives a very stable operation, without noise and with a reduced overheating.
The output ones use a double CV38 magnetic circuit built according to our standards. The I300 is the only integrated with such an output transformer.
A design mode that allows the device to appear much more powerful than its 10W may suggest!
As far as design is concerned, the I300 remains faithful to our range and has a compact design. The 2mm thick 304L chassis easily supports the weight of the other elements. For a better comfort of use it is equipped with a remote control.
Listening to the I300, it's all about accuracy, subtlety and musicality of the 300B which magnify your tracks. No doubt it will delight demanding audiophiles triode lover!
Product Strengths
- Wonderful mid-band presentation that comes from the 300B tubes
- Bass is extended and controlled
- Provides detail and insight into recordings without being piercing
- Soundstaging is wide, deep, and natural sounding
- Every stage in the amplifier has its own power supply, and particular care has been taken with the 300Bs themselves
Product Considerations
- The included remote is functional, but not in keeping with the quality of the amplifier itself
- It is very heavy, weighing 40kg
- The high polished chrome and gold accents may divide opinion
- Those looking for an amplifier that is absolutely neutral in its presentation may want to listen to something else
Comparisons (according to reviewers)
- Vs Merrill Thor amps, the Jadis I300, to the reviewer's ears, is a far superior amp for listening and putting a big grin on your face
Takeaway: The Jadis i300 is built superbly and delivers a balanced sound with detail and emotional connection, making it a joy to listen to. It is a refined performer across the audio spectrum and with all kinds of music.
Video review
Our take on the brand
Product Strengths
- Restores faith in humanity during an age dominated by digital devices
- Outstanding product crafted with high-quality metalwork, including a thick engraved panel, heat sinks that match the rounded edges, and internal components that are hand-soldered onto double-sided, 2 mm thick circuit boards
- Hybrid amplifier using a dual triode in the preamp stage and Mosfets in the output stage, offering the possibility to customize the sound by experimenting with different valves
- Offers unparalleled control over bass and extension, the mids are incredibly authentic, while the highs are enchanting in their golden glow, also boasts impressive attack, dynamics, and rhythm, along with remarkable speed
- Exceptional analogue amplifier primarily designed for high-quality sound through headphones—that also excels as a speaker stereo amplifier
Product Considerations
- Expensive
- Speaker declared power output is just 10W/8 ohms, which is enough to power a pair of medium-sensitivity speakers (88dB) in a small room if you don't push it too hard
Comparisons (according to reviewers)
- Vs Pass Labs XA30.8: Low bass was a bit bloomier, and that its virtual needle on the elasticity-to-damping metre sat slightly deeper in the elasticity zone
Takeaway: The Riviera Labs AIC-10 BAL is a high-quality, all-analog hybrid amplifier that works great with headphones and speakers and is designed for a very pleasurable listening experience, built with human hearing in mind. This is the right choice if one wants the best sound possible.
Video review
Our take on the brand
What competes at this price?
Our Summary
Product Strengths
- Refinement and smoothness in sound
- Exceptional build and finish, including exquisite woodwork
- Seductive midrange and overall musicality
- The Sinfonia has a romantic, addictive sound that's better suited to classical music
Product Considerations
- Not the last word in slam
- Needs careful system partnering to sound its best
- Dynamics were very good, although not exactly of the same caliber as with the ModWright preamp and amp
- When pushed to the extremes, during the most dynamic passages, the Sinfonia began to reach its limit—compressing gently and giving up some of the low frequency control
Comparisons (according to reviewers)
- Sinfonia offers a smoother, warmer, and more seductive sound, while the S6 amplifier sounds a little 'faster' and more linear
Takeaway: The Sinfonia is a fine amplifier with a beautiful build that delivers a refined and smooth sound. It's a good choice for enjoying music and will make your eyes smile with its hand-made Italian design.
Video review
Our take on the brand
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Our Summary
Product Strengths
- Addictive sound signature, unlike any other amp, with otherworldly instrument and voice reproduction
- Delivers serious magic with Fleetwood Deville and Klipsch Heritage speakers, revealing obscure details and creating a massive soundstage
- Dynamics for days
- Combines the qualities of a nice SET amp without the downsides, like noise or tube replacement
- Exceptional build quality and design with high-quality parts
- Only has two RCA inputs, no XLR balanced connections
Product Considerations
- Heavy speaker cables can cause the amp to tilt
- The volume dial functions as a gain dial, which may be different than what some users are accustomed to
- May not be suitable for hard-to-drive speakers in the 85db range that dip into 2–4 ohms
Comparisons (according to reviewers)
- The AMP23R offers more texture, layering, mid-bass, and vocal presence than Nagra INT
- The AMP23R is more organic, ethereal, and dynamic than Kinki Studio EXM1
- It sounds better than the Vinnie Rossi L2iSE, so long as the speakers are easy to drive
- The Enleum has more delicacy and finesse than Pass Labs and Cary Audio
- The AMP23R stacks up with the finest gear such as ampsandsound Bryce monoblocks
- Pass Labs First Watt SIT-3 offers a bit more organic, warmer presentation
Takeaway: The Enleum AMP-23R is a small but mighty integrated amplifier with a unique and addictive sound signature, and it is built with high-quality components. It's a great choice for those with sensitive speakers looking for a reference-quality system in a compact package.
Video review
Our take on the brand
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Our Summary
Product Strengths
- Very powerful amp with crazy headroom, capable of driving most headphones, including those that need a lot of power, and can grow with you as different headphones
- Delivers clarity, separation, detail, and impact, making every pair of headphones sound better
- Multiple impedance outputs allow dialing in the best sound for a given pair of headphones
- Super black background—very low noise floor
- A ton of different tubes can be rolled, including EL34s, KT66s, KT67s, KT88s, 6550s, and KT90s, making it very versatile and allowing customization of the sound to exact taste
Product Considerations
- Only one input via a pair of RCA connectors
- Requires a pre-amplifier or DAC with volume control if obtained without the volume pot
- May lack convenience features because of ampsandsound's minimalist philosophy
- Can be very heavy
Comparisons (according to reviewers)
- Vs Linear Tube Audio's Z10e: Z10e seemed more focused and brightly lit through the midrange
Takeaway: The Bigger Ben is a hugely versatile and powerful amplifier that could be an end-game amp, especially if you want to experiment with tube rolling. Its sound is detailed, clear, and engaging, making it a great choice for anyone who loves listening to music.
Video review
Our take on the brand
Our Summary
Product Strengths
- Exceptional build quality and aesthetics
- Delivers a robust 40 watts per channel into 8 ohms
- Demonstrates remarkable frequency handling, extending from 17Hz to 63kHz (-2dB)
- Precise bias adjustment with built-in meter
- Superb control, power, and effortless flow
Product Considerations
- Relatively heavy at 30kg
- May require occasional tube maintenance
- Power output might not suit all speaker combinations
- A softer 300B glow was not present
Comparisons (according to reviewers)
- The Triode as amp offered a similar kind of finely grained nearly neutral sound as the Audionet
- No amp has bettered the Riviera Levante integrated amp in dimensional quality
- Parts cost plus the Evolution comes with two Western Electric 300Bs that run $1499 per matched pair on the open market, while the Triode TRZ-300W sports four Triode-branded 300Bs
Takeaway:
The Triode Evolution is a high-end tube amp that delivers music with power and clarity. Those who value musical authenticity and appreciate the warmth of tube amplification may find it a great fit.
Video review
Our take on the brand
Our Summary
Product Strengths
- Exceptional build and manufacturing quality
- Sounds a little bit tubey for a solid-state amplifier, providing a gloss/warmth to the music
- Has the classic Class A characteristic of high perceived detail resolution alongside a relaxed presentation
- Delivers leading edges without the hardness typical of Class AB amps, and delivers them at high speed
- Can be used as single channel monoblock with a second AI 1.20, doubling the specified output
Product Considerations
- Only accepts single-ended RCA phono connections (until used in monoblock mode)
- Runs hot due to Class A operation and requires ventilation
- Some may want XLR inputs or digital inputs, which the AI 1.20 lacks
- The included remote is described as lightweight
Comparisons (according to reviewers)
- Vs Chord Electronics Etude: The Etude has a noticeably lower noise floor, more substantial/impactful bass, and more resolution, but the AI 1.20 has a smoother—more musical flow
- Vs Gryphon Diablo 300: The Diablo 300 has more raw power and authority in bass delivery, but the AI 1.20 pairing has better bass quality (tautness, incisiveness, and control)
- Vs Nagra Classic integrated amplifier: For less money, the dual AI 1.20s offer a lot more amplifier
Takeaway: The Canor AI 1.20 is a well-built amplifier that offers a smooth, musical sound with high detail resolution. It is especially impressive when used as a monoblock pair, delivering serious performance for audiophiles.
Video review
Our take on the brand
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