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
- Delivers 165 watts in pure class-A
- Musical sound with low level of distortion
- Fluid and clear mid-range with warmth close to tube amps
- Extended, transparent, and refined high range
- Timbric of instruments is very close to live performances, and harmonic richness makes everything intelligible and proportioned
Product Considerations
- Requires warm-up time before reaching optimal performance
- Dynamics could be better
- Very large cabinets
- The 'graphite' finish is a little heavy, with the reviewer preferring the 'silver' version
Comparisons (according to reviewers)
- Vs Pass Labs XA 30.5—at increased volume, the MPA-4 can keep up, maybe for the fact that they work exclusively in class-A
Takeaway: The Sugden MPA-4 offers a very balanced amplification with a musical sound and richness of detail. It involves the listener and makes them want to listen to entire records without fatigue.
What are hifi reviews useful for? (1) Identifying products you should demo in person at a dealer. (2) Learning which products reviewers unanimously praise as the best they've heard (this means they probably are legitimately great). (3) Identifying a product's attributes that satisfy your idiosyncratic needs and tastes. Beyond that, we often discount what reviewers say because they heap praise on most products—and are often apprehensive about publishing strong criticism or comparisons between products. Further, they seldom have more than a few products on-hand, often relying on their memories to compare past products. Always listen for yourself.
All
MPA-4
reviews
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An excellent review of a great product
/
Publisher
/
3/1/2022
An excellent review of a great product
Publisher
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3/1/2022
Video Review
Manufacturer details
Features
Specifications
- Inputs: Mono balanced
- Outputs: Single pair multi-way locking binding posts
- Input Sensitivity: 1 Volt for full output
- Power Output: 165 Watts into 8 Ohms both channels working
- Frequency Response: +/-0db 15Hz-30kHz
- Bandwidth: -3dB points 2Hz-200kHz
- Signal to Noise: >85dB
- Gross Weight (packed): 25kgs x 2
- Dimensions: 250 x 430 x 360mm (hwd)
Description
The popularity of the Masterclass series has resulted in over seventeen years of continuous production. Offering an excellent price/performance ratio it is easy to see why it remains so successful. With an abundance of headroom, the MPA-4 mono power amplifiers deal easily with heavy complex music, allowing the low level detail to be heard clearly and accurately. Boasting a fully balanced circuit design, it can be the engine room of a fully balanced hi fi system.
Release Timeline
Manufacturer Site
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:
- Sugden Audio amplifiers are meticulously handcrafted in England, with a strong emphasis on in-house design and production, ensuring a high level of quality control.
- The brand embraces Class A amplification. They offer a warmer, more organic sound than many modern amplifiers, with a presentation that prioritizes musicality and emotional connection over sheer power or technical specifications, making them ideal for long listening sessions.
- Sugden amplifiers often deliver a wealth of subtle details and micro-dynamics, contributing to a highly engaging and musical experience that allows listeners to fully appreciate the texture and timbre of instruments and voices.
Select products
Select product comparisons
A21 Integrated Line Amplifier
- Positioning: The entry-level high-end amplifier in Sugden's lineup.
- Description: Uses pure class A design, offering a large soundstage and depth. Its single-ended voltage rail circuit provides impressive dynamics and bass, distinguishing it from more complex models like the ANV-50, which features advanced output stages. Makes a great choice for those seeking simplicity and affordability without compromising on sound quality, especially if they do not require the higher power output or additional features of more expensive models.
ANV-50 Integrated Amplifier
- Positioning: A mid-range model in Sugden's Masterclass series, celebrating the brand's fiftieth anniversary.
- Description: Features a two-stage amplification system, combining a pure Class A amplifier with an advanced output stage for enhanced load stability. More powerful than the A21, offering 50 Watts into 8 Ohms, making it suitable for larger rooms and a wider range of loudspeakers. Its power supply and error correction circuits provide superior sound quality and reliability.
FBA-800 Class A Stereo Power Amplifier
- Positioning: A high-end power amplifier in Sugden's lineup, part of the Sapphire series.
- Description: Features a floating bridge design, which combines four amplifiers for a low noise floor and better power output. This model offers a full balanced mode from input to output, providing superior sound quality and load tolerance compared to the ANV-50 and A21.
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Avg. Product Price
$10,001-$20,000
Used For Sale
11
Available (Scroll Down)
Brand Popularity
208
of 900+
Badges
Top 50 Brand
Top 250 Brand
Products Listed
12
Founding Year
1967
Our take on the brand
Sugden Audio pioneered the first-ever solid-state Class A amplifier for home use in the 1960s and continues to hand-build all components in-house today. Their amplifiers deliver a warm, natural sound that appeals to both solid-state and tube amplifier enthusiasts, with their pure Class A operation providing a distinctive sound signature often compared to tube amplifiers.
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Brand Page
Our interview with the brand
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What's your approach to customer support?
What are your favorite tracks for showcasing the strength of your products?
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What if you spend more?
Balanced Audio Technology
Rex 500
25000
25000
/
5
Reviews
Balanced Audio Technology (BAT) designs all their components with fully balanced circuits and dual-mono power supplies, which deliver better channel separation and cleaner sound reproduction. BAT's signature approach includes zero global feedback and their Unistage circuit design, which amplifies the signal only once through a short signal path to preserve the original audio characteristics.
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Our summary
Product Strengths
- Powerful, able to drive any speaker at any level with ease
- Delivers a new dimension in realism at any volume level, exposing the timbre of bass instruments unlike ever heard before
- Reveals harmonic quality of instruments and voices
Product Considerations
- Heavy, weighing 140lb (63.5kg), requiring assistance for moving and unboxing
- High running temperature (55-65oC across the chassis) and draws 500W from the wall when idle
- When speaker cables are terminated with spade lugs, caution is advised as the posts are close together
- Output is floating—it should not be connected to any loudspeaker with a grounded 'black' terminal
- BAT components take a long time to "break in" (400-500 hours of use)
Takeaway: The BAT REX 500 is a very powerful amplifier that drives speakers with ease and reveals new levels of realism in familiar recordings. It is a must-audition for those seeking reference-level power amplification.
Video review
Our take on the brand
Balanced Audio Technology (BAT) designs all their components with fully balanced circuits and dual-mono power supplies, which deliver better channel separation and cleaner sound reproduction. BAT's signature approach includes zero global feedback and their Unistage circuit design, which amplifies the signal only once through a short signal path to preserve the original audio characteristics.
Product Page
Product Page
McIntosh
MC3500 Mk II
30000
30000
/
4
Reviews
McIntosh is one of the most iconic amplifier brands in the world, recognizable for its signature blue LED displays and distinctive industrial design. With a legacy spanning decades, McIntosh is known to many, even outside the audiophile community, and is sold in both mass-market retailers and specialized hifi stores. Their amplifiers are characterized by a warm, tube-like sound that enriches the midrange and smooths out the overall tonal balance.
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Our summary
Product Strengths
- Delivers 350 watts into 2-ohm, 4-ohm, or 8-ohm loads
- The design has a purity that is quite amazing
- Effortless power
- Soundstage is big
- Transparent
Product Considerations
- Not necessarily suitable for pairing with extremely cold sounding, sterile or bright speakers
Comparisons (according to reviewers)
- MC3500 is more open and airy, with base not as hard fisted, compared to Krell KSA 250
- It compares with brands like soulution, big Audio Research, and CH Precision, but at a lower cost
Takeaway: The MC3500 is an impressive amplifier that delivers a natural and pure sound, able to drive almost any speaker. If you're in the market for a McIntosh amp, this is the one that makes music sound pure, simple and unadulterated.
Video review
Our take on the brand
McIntosh is one of the most iconic amplifier brands in the world, recognizable for its signature blue LED displays and distinctive industrial design. With a legacy spanning decades, McIntosh is known to many, even outside the audiophile community, and is sold in both mass-market retailers and specialized hifi stores. Their amplifiers are characterized by a warm, tube-like sound that enriches the midrange and smooths out the overall tonal balance.
Product Page
Product Page
Electrocompaniet
AW 300 M
29000
29000
/
4
Reviews
Electrocompaniet, a nearly 50-year-old hifi brand recognized by audiophiles and major recording studios worldwide, specializes in amplifiers with unique features like Floating Transformer Technology and fully balanced operation. Their amplifiers are designed with direct-coupled high open-loop bandwidth topology and zero feedback class A operation.
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Our summary
Product Strengths
- Prodigious bass output and rich tonality, especially for a solid-state design
- Great presence, a black background, and strong resolution playing effortlessly at very high volume levels
- Offers a wide, well-defined soundstage
- Beautifully designed with a luxurious appearance, relatively compact dimensions, and attention to detail in its internal layout
- Reserves of power will comfortably drive a wide range of speakers to high levels
Product Considerations
- Attacks can be slightly soft on some material
- The soundstage, while wide and well-defined, may lack the pinpoint accuracy and layered depth of some reference amplifiers
- Requires support beneath it on carpeted floors to allow sufficient airflow
Comparisons (according to reviewers)
- Vs soulution 511, the soulution 511 was faster and more accurately conveyed bass notes, threw an image with greater accuracy, and was more open on top
Takeaway: The Electrocompaniet AW 300 M is a gutsy and poised monoblock amplifier that delivers lots of power and handles a variety of speakers, giving an excellent listening experience. Its solid build and high performance make it a great choice for those seeking high-end audio quality.
Video review
Our take on the brand
Electrocompaniet, a nearly 50-year-old hifi brand recognized by audiophiles and major recording studios worldwide, specializes in amplifiers with unique features like Floating Transformer Technology and fully balanced operation. Their amplifiers are designed with direct-coupled high open-loop bandwidth topology and zero feedback class A operation.
Product Page
Product Page
MOON
861
21999
21999
/
4
Reviews
The MOON 861 is a power amplifier with the pedigree of the distinguished MOON 888 and the wholistic design philosophy of the North Collection.
MOON by Simaudio is known for their warm and natural "MOON sound," achieved through their proprietary Lynx circuit that eliminates global-feedback loop in their amplifiers. Their products feature fully balanced circuitry and customizable interfaces, with designs that minimize noise and distortion while revealing intricate audio details without harshness.
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Product Strengths
- Great build quality that feels solid and built to last
- Impressive control, speed, and transparency in sound reproduction, resulting in a highly satisfying and natural sound
- Excellent bass grip, with precisely layered and insightful basslines
- Each instrument is distinct within the orchestra
Product Considerations
- Speaker cable terminals are a bit tight, especially with larger spades
- Software may need updates to ensure devices connect seamlessly
- Setup may be crucial to get the best sound
- According to one commenter, the treble can be hard and tiring
Comparisons (according to reviewers)
- The 861 exceeds the Moon 860A v2 in performance due to improvements in isolation, mechanical damping, and power supply
- The 861 has less pronounced colors than Burmester 218 amplifiers
- The 861 has more weight and oomph than Octave MRE 220 SE
Takeaway: The Moon 861 is a powerful and well-built amplifier that delivers a natural and detailed sound, with excellent control and dynamics. With its power and balanced sound, listeners may find themselves enjoying music even more.
Video review
Our take on the brand
MOON by Simaudio is known for their warm and natural "MOON sound," achieved through their proprietary Lynx circuit that eliminates global-feedback loop in their amplifiers. Their products feature fully balanced circuitry and customizable interfaces, with designs that minimize noise and distortion while revealing intricate audio details without harshness.
Product Page
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What competes at this price?
Chord Electronics
Ultima
15375
/
Released
2023
The ULTIMA mono power amplifiers have been conceived for the very finest high-end audio systems, those which by their very nature, tend to have the most demanding and most difficult-to-drive large loudspeakers. They deliver unsurpassed power and are capable of effortlessly driving any speaker.
Chord Electronics designs and manufactures all their products in Great Britain, setting themselves apart by using proprietary FPGA technology instead of off-the-shelf DAC chips found in most competitors' products. Their DACs and portable audio devices, featuring distinctive color-changing buttons and portholes, deliver studio-grade performance through unique technologies like the Watts Transient Aligned filter, which provides more natural and detailed sound reproduction.
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Our Summary
Product Strengths
- Offers a remarkably smooth, unforced, and natural presentation with a touch of warmth
- Excels in detail retrieval and textured presentation of instruments and vocals, making the music feel alive
- Presents a wide and holographic soundstage, especially when paired with speakers that are already strong in this area
- Demonstrates agility, precision, and clarity, combined with a naturalness that eluded earlier generations of Chord amplifiers
- Scales dynamically and has the ability to punch hard when required
Product Considerations
- Has a minimalist design with just four line-level inputs, lacking features like phono stages, tone controls, headphone outputs, or DAC modules
- Some may find its sonic signature prioritizes articulation over qualities such as richness and authority, potentially sounding thin if partnered poorly
- Balance control has no center indent or marked position
- The polychromatic lighting may be an issue for the color-blind
- Remote operation can be affected by direct sunlight
Comparisons (according to reviewers)
- Vs Rega Elex-R Mk3, the Chord Ultima Integrated delivers undeniably elevated sound in all respects, with greater dimensionality and smoother vocals
- Vs Bryston 7B 3 monoblocks, the Chord Ultima Integrated offers a weightier and more thunderous delivery, especially in the midrange and vocals, with more inner warmth in tone
- Vs Benchmark AHB2, the Chord Ultima Integrated provides a more energetic and fun listening experience, with Thor-like bass impact and overall superior dynamics
- Vs Accuphase E-270, the Chord Ultima Integrated is warmer, rounder, more powerful, and refined, with a more fluid and emotionally engaging performance
Takeaway: The Chord Ultima Integrated is a unique and well-built amplifier that combines a visually pleasing design with a captivating sound, full of detail and dynamic precision. It brings music to life with an engaging and immersive experience, making it a worthy addition to any audiophile's setup.
Video review
Our take on the brand
Chord Electronics designs and manufactures all their products in Great Britain, setting themselves apart by using proprietary FPGA technology instead of off-the-shelf DAC chips found in most competitors' products. Their DACs and portable audio devices, featuring distinctive color-changing buttons and portholes, deliver studio-grade performance through unique technologies like the Watts Transient Aligned filter, which provides more natural and detailed sound reproduction.
Product Page
Product Page
AGD
Duet
11500
/
Released
2024
AGD Productions uses GaN (Gallium Nitride) technology in their amplifiers, which are housed in glass tubes reminiscent of classic vacuum tubes, delivering high power from a compact size with near-perfect square waves. The amplifiers are designed to be upgradeable as technology advances, with GaN modules that can be replaced, while handling complex impedance loads similar to high-end Class-A or SET tube amps.
Expand Details
Our Summary
Product Strengths
- Compact size, lightweight, and runs cool compared to traditional high-end amplifiers
- Exceptionally quiet operation, with reviewers noting a complete absence of hum or buzz
- Delivers a clean, crisp, and neutral sound signature without added coloration
- Upgradeable design, allowing users to update the amplifier with new GaN modules as technology evolves
- Produces a Single Ended Triode-like midrange and top end
Product Considerations
- The polished finish is a fingerprint magnet, requiring the use of gloves for handling
Comparisons (according to reviewers)
- Vs AGD Audion MKIII: The Duets offer a cleaner and more refined sound with improved bass and greater immediacy and snap compared to the Audion MKIII
- Vs Daniel Hertz Maria: The AGD Duets seem to have a little more inner resolution
- Vs Pass Labs X250.8: The AGD Duets performed to a higher level
- Vs Peachtree GaN 1/VTV GaN amps: AGD amps seem to be on another level in regards to design, and the sound is more refined and beautiful
- Vs Aavik U-150, Luxman 595, Yamaha A-S 3200, Axxess Forte 1, Line Magnetic 219ia: The AGD Duets performed to a higher level
Takeaway: The AGD Duet amplifiers offer a blend of cutting-edge technology, exceptional sound quality, and user-friendly design. They are a great option for those seeking a high-end audio experience in a compact and energy-efficient package.
Video review
Our take on the brand
AGD Productions uses GaN (Gallium Nitride) technology in their amplifiers, which are housed in glass tubes reminiscent of classic vacuum tubes, delivering high power from a compact size with near-perfect square waves. The amplifiers are designed to be upgradeable as technology advances, with GaN modules that can be replaced, while handling complex impedance loads similar to high-end Class-A or SET tube amps.
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Product Page
ASR
Emitter II
18750
/
Released
The Emitter II models are considered by true music connoisseurs and uncompromising audiophiles as the ultimate in amplifier construction. Through word of mouth alone, a music-addicted and steadily growing global fanbase has developed, who have realized their desire for a concert hall in their home environment. Powered by two separate power supplies, the most demanding speakers and elaborately built dynamic transducers are driven to peak sonic performance.
ASR Audio's Emitter II Exclusive amplifier creates a vast, tube-like soundstage and three-dimensional presentation without tube colorations, while maintaining exceptional transparency and a low noise floor. The brand stands out for its emphasis on measurements and scientific analysis in audio equipment evaluation, often sparking debates between measurement-focused and subjective listening-focused audiophiles.
Expand Details
Our Summary
Product Strengths
- Known for combining the musicality of tube amplifiers with the precision and power of solid-state amplifiers.
- It provides a transparent sound with steel control, without the electronic 'shine' associated with transistor amplifiers.
- Exceptional bass performance, described as deep, explosive, and completely controlled.
- Homogeneous frequency range, offering a very high degree of transparency and control.
- Offers an ability to resolve even the finest musically significant details.
Product Considerations
- Requires a substantial amount of space due to its multi-component design.
- The sound offered might be 'too beautiful' for some listeners, as it is not 'brutal' or 'terse' enough.
- Requires care in using its switches to avoid shutdowns.
- Some reviewers note it was 'dark sounding' on the highs, though it did not lack information.
Comparisons (according to reviewers)
- Compared to Quad ESL loudspeakers, it surpasses the musicality and clarity achieved with many tube amps, rivaling even high-end options like Lamm Industries ML2.2 and Miyajima Laboratory 2010.
- The ASR has better bass and is more transparent than MBL, however, it lacks the grace that MBL offers.
- Compared to Rogue 180W monoblocks, the ASR Emitter II delivers better bass.
- The ASR Emitter II has slightly better bass control than Manley Neoclassic 500, but the Neoclassic 500 has a more marvelous style of fiddling.
- Compared to Edge and Audio Research, the ASR is darker sounding.
Takeaway: The ASR Emitter II Exclusive offers a combination of tube-like warmth and solid-state precision, making the listening experience a very involving one. It provides exceptional control and detail across the entire frequency range, making it a great choice for audiophiles.
Video review
Our take on the brand
ASR Audio's Emitter II Exclusive amplifier creates a vast, tube-like soundstage and three-dimensional presentation without tube colorations, while maintaining exceptional transparency and a low noise floor. The brand stands out for its emphasis on measurements and scientific analysis in audio equipment evaluation, often sparking debates between measurement-focused and subjective listening-focused audiophiles.
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Product Page
Audio Research
Reference 80S
18500
/
Released
2021
The Reference 80S stereo amplifier continues Audio Research's latest design effort in creating a vacuum-tube amplifier that not only redefines ultimate music reproduction, but does it in an incredibly beautiful package. The 80S was created with as much spirited authority as we can pack into a compact circuit with 2 KT150 tubes per channel for music lovers who want Reference-level performance at the lowest possible barrier to entry.
Audio Research is a hifi brand that has stayed committed to tube technology while many competitors moved to solid-state designs. The brand is known for its use of KT150 power beam tetrodes and hybrid power supply designs that blend tube amplification with solid-state regulation.
Expand Details
Our Summary
Product Strengths
- Delivers power while handling subtlety and fine detail with aplomb
- Presents an engaging and naturally organic soundstage
- Offers switchable Ultralinear and Triode tube configurations
- Hand-wired, hand-soldered, and hand-assembled
- The top end is silky, resolved, and decent, resulting in no listening fatigue
Product Considerations
- The bass is not that punchy as with the best high-end amplifiers
- The amplifier can be demanding towards the acoustics of the room due to its heavy-on-bottom balance
- Limited power handling that does not allow for playing too loud
- The 80S sounds more homogenous, although the listening is rewarding and entertaining
- Ensure existing speakers will work with the Reference 80S to satisfaction before purchase
Comparisons (according to reviewers)
- Vs Simaudio Moon 860A v2 power amplifier, the voice of Hana was warmer and velvetier through the Audio Research—a bit more human for my ears—although the sound was slightly less transparent and less controlled
Takeaway: The Audio Research Reference 80S is a tube power amplifier that delivers precision and subtlety. If high-end audio is desired and a lot of power is not necessary, the Reference 80S could be a good fit for a listening space.
Video review
Our take on the brand
Audio Research is a hifi brand that has stayed committed to tube technology while many competitors moved to solid-state designs. The brand is known for its use of KT150 power beam tetrodes and hybrid power supply designs that blend tube amplification with solid-state regulation.
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Product Page
MOON
761
14000
/
Released
2023
MOON by Simaudio is known for their warm and natural "MOON sound," achieved through their proprietary Lynx circuit that eliminates global-feedback loop in their amplifiers. Their products feature fully balanced circuitry and customizable interfaces, with designs that minimize noise and distortion while revealing intricate audio details without harshness.
Expand Details
Our Summary
Product Strengths
- Uses Moon's new distortion-canceling amplifier circuit, which is incredibly precise.
- Runs as efficiently as possible, yet as close as possible to class A.
- Capable of playing at any volume level, from a whisper to a scream.
- Delivers 200 watts per channel.
- Delivers good stereo, with very powerful dynamic range.
Product Considerations
- Only available in a two-tone 'panda' color scheme (silver sides with a black front panel) at the moment, though this may change with demand.
- Existing Moon aluminum bridges for stacking components are not compatible with this model.
- Moving the 35kg power amp can be a bit of a struggle.
- Although it has a lot of heat sinking, and it does get warm, it's not pulling a huge amount of energy out of the wall at any given volume level.
Comparisons (according to reviewers)
- Vs Hegel H20—the 761 has additional refinement, additional resolution, and is much smoother, but doesn't lose any detail in the music.
Takeaway: The 761 is a very capable amplifier that gives the potential to drive at any level and has the power to play precise, fine-sounding music. It can be used in bridged mode and works in balanced and single-ended configurations.
Video review
Our take on the brand
MOON by Simaudio is known for their warm and natural "MOON sound," achieved through their proprietary Lynx circuit that eliminates global-feedback loop in their amplifiers. Their products feature fully balanced circuitry and customizable interfaces, with designs that minimize noise and distortion while revealing intricate audio details without harshness.
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