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
Magazine reviewers and YouTubers have tried this product—so we've summarized their strongest opinions below.
Compared to their other products
We think it's helpful to understand how this product fits into the brand's full lineup (below). To learn more about these products, visit the brand's page.
ATC-3
- Positioning: The entry-level stereo line-control amplifier designed for affordability and ease of use.
- Description: Features a simple SRPP design with a reinforced buffer stage and a quick recovery diode power supply that offers very low noise. Compared to the more advanced ATC-7, it has fewer features and lower output capability, making it best for small rooms and buyers with a tighter budget and basic functionality needs.
ATC-7
- Positioning: The mid-range stereo line-control amplifier focused on precise signal handling.
- Description: Uses dual 12AX7 and 12AU7 valves to deliver precise control, a wide frequency range, and low distortion. Compared to the entry-level ATC-3, it offers enhanced performance and output voltage while leaving the high-powered driver role to the ATM series.
ATM-1S
- Positioning: The stereo power amplifier built to deliver dependable and balanced performance.
- Description: Uses a traditional Mullard phase inversion circuit with 6CA7 valves and robust Hashimoto transformers to achieve 36W per channel with solid headroom. Compared to the flagship mono BLOCK ATM-3211 and the preamp line (ATC-7 and ATC-3), it strikes a balance in cost and power.
ATM-3211
- Positioning: The high-end mono power amplifier engineered for maximum power delivery.
- Description: Uses a five-year developed 211 triode push-pull circuit that produces 120W output with a wide frequency response and premium hand-picked components. Compared to the stereo ATM-1S and the preamp ATC series, it offers higher output power and superior build quality.
Read the reviews
ATM-2001/ATM-2001S
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Manufacturer's notes
Our take on the brand
Used
A&M
What if you spend a bit more?

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.
Our Summary
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

Our Summary
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

Possessing formidable power, unrivalled technology and a herculean appearance this amplifier delivers electrifying signals to your loudspeakers, transforming your music into a thrilling experience.
craftsmanshipLow frequencies are faithfully reproduced without a whiff of constraint. Spellbinding vocals have astonishing reality and territory around them.
Monopolizing your leisure time, the addictive clarity and power of each musical note, riveting you into a state of blissful abandonment.
Highly skilled craftspeople take enormous pride in hand building each amplifier, scrupulously checking and testing every parameter, so your enjoyment is forever untroubled.
Power on tapUnprecedented power is yours to unleash, delivering an astonishing musical performance. Concealed within the crafted exterior lurks a gargantuan 2300VA mains transformer delivering mountainous levels of current to feed your musical hunger.
Accomplishing the largest crescendos turns into child's play with 272,000uF of electrical brawn just itching to be discharged.
Reassuringly cool, even under your most sustained inclination to blast away the cobwebs, it is gratifying so much power is on tap.
Our Summary
Product Strengths
- Build quality is among the best, with all pieces fashioned from solid aluminum
- The system delivers an effortless and truly reference-level sound
- Produces deep and powerful bass that energizes the room with ease
- Offers stunning analogue playback with incredible soundstaging, holographic image, depth, and width
- Delivers music with startling clarity across all genres
Product Considerations
- The Reference Preamplifier lacks a remote, focusing on a purist design
- The Reference Three speakers are very heavy—weighing 100kg net
Comparisons (according to reviewers)
- The Avid Hifi Reference system performed similarly well with Fanfare for the Common Man, producing impressive bass and dynamics, compared to the YG Acoustics system with Boulder
Takeaway: The AVID HiFi Reference system is a top-tier system delivering exceptional sound quality and effortless power. It is designed to provide an extremely enjoyable and immersive music experience, making it a worthwhile investment for serious audiophiles.
Video review
Our take on the brand
What else 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
- Musically complete, providing sound that is honest, true, thrilling, heart-warming, and emotionally rewarding
- Able to drive difficult speaker loads with complex impedances and very low overall impedance
- Offers real-time monitoring and automatic protection
- The design results in musical triumph of transparency, nuance and dynamics
- Ed Meitner is a respected designer
Product Considerations
- During a test of maximum power into 2 ohms with one channel driven, the amplifier went into standby mode
- The size (544mm wide and 584mm deep) and weight (82kg) of the MTRS may make it difficult to fit into a hifi rack and move
- The input selector buttons on the partnering PRE preamplifier can be tricky to use
- The down-firing status light colors may not match the manual's description
- Bass flabbiness was noted around 68-77Hz due to room node exacerbation
Comparisons (according to reviewers)
- Compared to monoblocks, the MTRS may not deliver as wide a soundstage or as breathtaking dynamic contrasts
- The partnering PRE preamplifier is as close to the proverbial 'straight wire with gain' as has been seen, heard and measured in HFN for many years
Takeaway: The EMM Labs MTRS amplifier is a musically rewarding and transparent choice, especially when paired with its PRE preamplifier, and can drive difficult speaker loads well. The MTRS offers sophisticated protection and is built with exacting engineering.
Video review
Our take on the brand

Our Summary
Product Strengths
- Very clean and noise-free output signal provides a stable soundstage with a very black background at any sound level
- Exceptional bass control and depth delivers a powerful and tight bass response that underpins the overall musical experience
- Offers flexibility with mono, stereo, and bi-amping operating modes, allowing for system upgrades and configuration changes
- Dynamic and fast, reacting instantaneously to the signal it receives and delivering power and subtlety where needed
- Continues the company's aesthetic with the massive perspex front panel covering
Product Considerations
- Speaker binding posts may not be compatible with all types of speaker cable terminations, specifically thicker spades
- The control for the illuminated 'E' on the front is located underneath the amp and may be difficult to access
- May be more 'laid-back', which some may interpret as lacking ultimate transparency or strict neutrality
- Provides only for XLR balanced inputs, though Electrocompaniet can provide appropriate high-quality adaptors for RCA connectors
Comparisons (according to reviewers)
- Brings another level of control and depth to everything, compared to Totaldac Amp 1
- The memorable blackness of bass pinged recognition, compared to Kinki Studio EX-B7 monos
Takeaway: The Electrocompaniet AW 800 M is a powerful and versatile amplifier known for its exceptional bass control, clean output, and dynamic performance. It is a great choice for audiophiles seeking a high-quality listening experience with flexibility for system configuration.
Video review
Our take on the brand

Our Summary
Product Strengths
- Incredibly resolving, with plenty of detail
- Perfectly controlled, 'wide' sound in terms of dynamics and panorama
- A quieter background brings forward a level of detail
- A clearly structured form, with symmetrical divisions and repetitions
- Inspired by the Relentless Epic amplifier series
Product Considerations
- Speaker jacks accept only spades and bare wires, and connecting spades from the top bends the cable significantly
- Components on the rear panel are placed close to each other and not particularly convenient to use
Takeaway: The Momentum S250 MxV amplifier delivers an immersive and detailed listening experience, making it great for those who enjoy actively listening to music. It brings out the best in loudspeakers, offering tremendous dynamics and a wide soundstage.
Video review
Our take on the brand

Our Summary
Product Strengths
- Designed by Ed Meitner, a respected engineer known for his work in digital audio and analog mixing consoles
- Delivers a neutral, honest, true, thrilling, heart-warming, and emotionally rewarding sound
- Capable of driving most speakers with ease due to its high power output
- Features a hybrid power system with newly designed toroidal transformers and a switch-mode power supply
- Incorporates real-time monitoring and automatic protection to prevent speaker and amplifier damage
Product Considerations
- Its sheer size and weight make it difficult to place and move
- One review notes an issue with maximum power into 2 ohms, where the amplifier went into standby mode during a test
- May transmit more bass than some users are accustomed to, potentially exacerbating room node issues
- Conflicting information about the status light colors
Comparisons (according to reviewers)
- Compared to Nagra, D'Agostino, and McIntosh amplifiers, the MTRS is considered more neutral, while those are warmer
Takeaway: The MTRS is a high-end stereo amplifier known for its neutral and musical sound, designed by a legendary engineer and capable of driving most speakers. Its advanced technology and protective features provide a reliable and enjoyable listening experience.
Video review
Our take on the brand
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
Magazine reviewers and YouTubers have tried this product—so we've summarized their strongest opinions below.
Want to see more similar products?
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