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
- Improved high-frequency response melds lower saturation voltage with higher gain
- An upgraded output stage includes 48 power transistors and a 2000VA power supply transformer with nearly 100,000 microfarads of power supply storage capacitance
- A new and far more efficient heatsink design borrowed from the Relentless
- Can remain in class-A for up to the first 100W of their output
Product Considerations
- One of the amps wasn't working properly the entire time
- Measurements may not be stellar, even though the D'Agostino website claims that the Progression's 'distortion, signal/noise ratio, channel separation, and bandwidth measurements have all improved'
Comparisons (according to reviewers)
- The Progression M550 monoblocks replaced the original Progression monos
- Dan D'Agostino said that if he'd listened to the new Progression M550s when he designed the original Momentum monoblocks 10 or 11 years ago, he would have declared the Progression M550s better
- The Progression M550 borrowed from the Momentum
- The M550 borrowed from the Relentless
Takeaway: The Progression M550 monoblocks are a significant advance, with technological improvements resulting in a 'new amplifier' design. The M550s aim to provide both high-powered delivery when needed and sonic accuracy.
All
Progression M550
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Manufacturer details
- Frequency Response: 1 Hz to 80 kHz, -1 dB / 20Hz to 20 kHz, ±0.01 dB
- Signal-to-Noise Ratio: 105 dB - unweighted / 75 dB - A weighted
- Input Impedance: 100 KΩ
- Output Impedance: 0.1Ω
- Power: 550 watts @ 8Ω, 1,100 watts @ 4Ω, 2,200 watts @ 2Ω
- Distortion: .015% @ 1 kHz (550W @ 8Ω)
- Inputs: 1 balanced XLR
- Dimensions: 17.875 x 9.0 x 23.0 in (45.4 x 23.0 x 58.4 cm)
- Weight: 115 lb (52.2 kg)
Reflected in the model name, the Progression M550 Mono Amplifier delivers 550/1,100/2,220 watts into 8/4/2 ohms. The Progression M550 includes major revisions to the input topology. Distortion, signal/noise ratio, channel separation, and bandwidth measurements have all improved. New transistors handle six times the power of the previous components and a new DC coupling circuity has improved low frequency performance and extended the bandwidth of the amplifiers.
Pairing this advanced front end to the enhanced output stage has improved the dynamic impact, detail retrieval, and spatial integrity of the amplifier's playback. The audio signal path throughout is discrete, balanced, and direct coupled. Advanced protection techniques shield the amplifier and associated components from any unexpected anomaly.
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:
- The lacquered copper heatsinks with venturi tunnels and Breguet-style dials are distinctive visual elements that have been a consistent feature of D'Agostino's amplifiers from the beginning.
- Dan D'Agostino designs his solid-state creations to be as accessible and 'ear-friendly' as the best valve amps, achieving a sound that is organic, natural, pleasant, and even friendly.
- D'Agostino amplifiers are meticulously hand-built, with painstaking attention to detail and precision in component placement.
Select products
Progression Series
- Positioning: The entry-level line in the D'Agostino amplifier lineup.
- Description: Known for powerful output and musical finesse, making them suitable for larger rooms and those seeking high power without the flagship price.
Momentum Series
- Positioning: Sits in the middle of the D'Agostino lineup.
- Description: Delivers substantial power and refinement in a compact chassis. They incorporate advanced circuit topologies and a unique input stage, setting them apart from the Progression series, which focuses more on raw power.
Relentless Series
- Positioning: The flagship line of D'Agostino amplifiers, representing the pinnacle of performance and luxury.
- Description: Designed without limits, offering practically unlimited power and the ability to drive any loudspeaker to its fullest potential. They feature groundbreaking circuit topologies and new power transistors, differentiating them from the Momentum series, which focuses on compact design and refinement.
Our take on the brand
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Used
Dan D'Agostino
What if you spend more?
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.
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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
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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
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.
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 competes at this price?
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
- Pleasing and natural sound at lower listening volumes, reminiscent of tube amplifiers
- Remarkable level of dynamic control over the loudspeaker load, even when pushed to high volumes, resulting in no perceived distortion, sibilance, or unpleasantness
- Warm and engaging sound stage with clarity in imaging and separation of musical elements
- Capable of handling massive dynamic shifts without compromising its panoramic soundstage—showing immense grace under pressure
- Design ensures efficient heat dissipation through convection cooling, ensuring optimal thermal management
Product Considerations
- No functionality to allow for dimming of the internal lighting, which could prove problematic in some light-sensitive home theatre configurations
Comparisons (according to reviewers)
- Vs McIntosh MC1201 monoblocks: Hard to notice a difference in their performance, even at insane listening levels, despite the McIntosh having a much higher power rating
Takeaway: The ML-50 is a visually stunning and technologically advanced amplifier that produces a lovely, subtly warm tonality whilst still sounding crystal clear. It is neutral yet detailed enough to handle any genre of music, making it a worthwhile investment for audiophiles seeking a no-compromise system.
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
- Delivers a complete and unabridged rendition of music, offering a sense of authority and positively influencing the sound
- Presents music as a tightly unified whole, creating a singular event rather than a collection of individual sounds
- Offers beautifully balanced and poised sound across the entire frequency range, from deep bass to detailed highs
- Maintains steady output voltage regardless of changes in load, defying mains input variations, thanks to the Utopik power supply
- The Adaptive Bias Control (ABC) technology establishes and adjusts bias current in real time
Product Considerations
- The high price dictates that all other system components (source, pre-amplification, speakers, supports) need to be of similarly high quality and expense
Takeaway: The Linn Klimax Solo 800 is an uncompromising amplifier that allows one to hear their music in a new light by delivering a complete picture of the sound. It offers exceptional clarity, balance, and control over the music signal.
Video review
Our take on the brand
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Our Summary
Product Strengths
- Transparent and uncolored
- Exceptional casework and styling
- Ample power without muscularity becoming the product's defining attribute
- Utterly effortless and transparent magnification of the electrical impulse
- Allows a listener to devote their psychic energy to making an emotional connection to music
- Only has balanced inputs
Product Considerations
- Only has balanced inputs
Takeaway: The Ferios monoblock power amplifiers are some of the best electronics available, combining immediacy, transparency, and tonal beauty. Its ability to effortlessly resolve complex arrangements makes it a worthwhile choice for serious audiophiles.
Video review
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