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
- Excellent soundstaging, providing a well-defined dimension of depth
- Extended bass response with greater detail and impact
- Transparent, revealing changes in components, making it a valuable tool for critical listening
- Neutral overall presentation with sparkling high frequencies and detailed bass
- Rugged design; the amplifier was not damaged by a tube failure
Product Considerations
- Driving a 4-ohm load with the S-30 Mk III is not recommended without an external autoformer
- Requires a preamp with lots of gain due to low input sensitivity through the RCA inputs
- Connecting preamp to amp can be challenging due to the input jacks being on the front panel
- The owner's manual could benefit from a description of a jumper and a picture showing how to connect it when using unbalanced inputs
- The binding posts are not clearly marked to show which terminal was positive and which negative
Comparisons (according to reviewers)
- The S-30 Mk III has better-controlled bass and more power than the Art Audio PX 25, while the PX 25 excels in the midrange
Takeaway: The Atma-Sphere S-30 Mk III is an amplifier that offers sound quality and dynamics. It is a good choice for those seeking a high-performing amplifier with a design.
All
S-30
reviews
Manufacturer details
- Output power: 30 watts per channel into 8 Ω, 45 watts per channel into 16 Ω
- Input Impedance: 100 KΩ single-ended, 200 KΩ balanced
- Output Impedance: 7 Ω
- Input: 3 V sensitivity RCA and XLR true balanced input
- Tube complement: 10 x 6AS7G output tube, 6 x 6SN7 driver tube
- Gain: 23dB (for 8 Ω)
- Power Bandwidth: 2Hz-75KHz within ½ dB
- Frequency response: 1Hz-200KHz within 3 dB
- Hum and noise: Less than -75db below 1 watt, -95db below full power
- Distortion: THD typically 1% at full power, IM distortion typically under .04% at full power
- Phase shift: less than 1° @ 20KHz
- Output section risetime: 600 V/µs
- Feedback: 2 dB
- Power consumption: 400 watts
- Dimensions: 13" deep x 17" wide x 8" tall (33 x 43 x 20 cm)
- Weight: 24 lbs (10.9 kg), without tubes
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:
- Atma-Sphere's designs center around "Balanced Differential Design," ensuring fully balanced circuits in every component for enhanced signal purity.
- As an output transformerless (OTL) amplifier manufacturer, they are known for designs which avoid output transformers, resulting in faster response and a more direct connection to the music.
- Atma-Sphere's Class D amplifiers offer a solid-state option with the goal of replicating the smoothness of their tube amplifiers while improving efficiency and reducing distortion.
Select products
MA-1
- Positioning: The entry-level amplifier designed for compact and simple setups.
- Description: Uses a straightforward circuit and build with essential connectivity that makes it ideal for small rooms and modest sonic goals. Compared to the MP-3 or MA-3, keeps costs low while delivering the basic functions needed for everyday audio without additional features.
MP-3
- Positioning: A mid-range solution that balances simplicity with added digital and connectivity features.
- Description: Offers a cleaner digital processing design and improved signal clarity compared to the MA-1, making it a step up for users seeking more control. In contrast with the higher-tier MA-3, M-60, and GEM, provides moderate performance improvements and connectivity enhancements.
MA-3
- Positioning: A higher-performance amplifier aimed at audiophiles requiring refined audio detail.
- Description: Integrates advanced circuitry and improved power supply management to deliver a richer sound compared to both the MA-1 and MP-3. When compared with the more powerful M-60 and flagship GEM, offers a balanced mix of technical upgrades and connectivity options.
M-60
- Positioning: A robust integrated amplifier built for larger environments and more versatile functionality.
- Description: Uses a more sophisticated design with higher power output and expanded connectivity that distinctly outperforms the MA-3 in handling larger room acoustics. Relative to the lower-priced models, provides additional technical features and a broader suite of functionalities.
GEM
- Positioning: The flagship model delivering the most advanced audio performance in the lineup.
- Description: Incorporates groundbreaking technologies and premium components that ensure unmatched clarity and dynamic range compared to the M-60 and all other models. In contrast to every other product in the series, its refined build, extensive functionality, and top-tier performance are aimed at users with high budget tolerance and demanding sonic goals.
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?
One thing that distinguishes us from other manufacturers is our craftsmanship. Open the amp or preamp up and it’s pretty obvious when compared to our competition. We also price according to a formula rather than what the market will bear, so our equipment tends to be less expensive. Of course, we are well known for our OTLs. We have also embraced balanced line operation longer than anyone else in high-end audio with the first balanced line preamps ever made for home audio.
What's your approach to customer support?
We handle customer support directly if we can. It’s nice if a dealer can do it for us, but quite often they get in over their head, so we recommend the customer contact us directly if at all possible. We stand behind our products and support amps and preamps we made a long time ago with an update program that allows the older product to meet the specs of the new with a new warranty. We’re not picky about the length of the warranty and have warranted equipment that was well out of the regular warranty period.
What are your favorite tracks for showcasing the strength of your products?
I like to play a variety of tracks to show off our gear. We made a recording called Canto General which, because I was there, I like to use as a reference since it will tell me how well a system is imaging, how well it’s handling voices and bass, as well as dynamic contrast. We issued it on LP and CD. The CD is still available, but the LP was only 1,000 pressed and sold out a long time ago. Otherwise, I like to play stuff that shows off the bass. One recording I use for that is Remotion by Global Communication. Female voice is often requested at shows, so I might put on something by Pentangle on the TransAtlantic label, or The Secret Garden by the John Renbourn Group.
What other products pair best with yours?
Our MA-2s get used a lot with Sound Lab ESLs. The M-60s get used a lot with older Quad ESLs and horn systems. Our preamps work nicely with most power amps that have a true balanced input, like Pass Labs.
Used
Atma-Sphere
What if you spend more?
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Product Strengths
- Impressive bass response, dynamics, and power for a 12-Watt single-ended tube amplifier
- Dense, tactile, and sweet harmonic color with a clean and clear sound
- Robust build quality with point-to-point hand wiring and exceptional parts
- Easy biasing with a switch for KT88 to KT120/150 mode
- Proprietary transformers that contribute to a flatter response and deeper low bass
Product Considerations
- Careful speaker matching is required, ideally with speakers that have at least 94dB/W efficiency and a stable speaker load
- Must be turned off for at least 10 minutes, preferably 30, before turning it back on, or the rectifier tube could blow
- The correct tube type must be selected on the back of the amp, otherwise performance could be lackluster or tubes could be damaged
- The XLR input involves a slight reduction in detail due to using an input transformer to convert the incoming balanced signal to single-ended
Comparisons (according to reviewers)
- The Bryce eliminates the shortcomings of ampsandsound Nautilus when used as a speaker amplifier, adding dynamics, bass, and an extended top end
- The Bryce monoblocks are more romantic in execution, with single-ended construction—compared to the push-pull output of ampsandsound Zion
Takeaway: The Bryce Monos are high-quality amplifiers with a surprisingly powerful and detailed sound, providing an engaging listening experience. They are great for audiophiles looking for a tube amp that delivers both emotional connection and technical performance.
Video review
Our take on the brand
The SE300B Mono Amplifier is... an all-tube power amplifier employing the famous classic 300B filamentary triode in single-ended operation mode for an output of up to 10 watts into a 4, 8 or 16 ohm loudspeaker load. The 300B power tube is excited by an extraordinary single-stage driver employing two CV2382/EL822 power pentodes operated in triode mode with high idle current and works into a C-core output transformer built in-house to the highest possible standards so as to ensure ultimate performance. The amplifier is built with meticulous hand construction using our proven point-to-point wiring techniques whereas much care has been taken in arranging each aspect of the internal construction to ensure low noise performance, ease of service and the highest reliability for many years to come.
Our summary
Product Strengths
- Pure sound, free of coloration while retaining musical detail, allows a graceful and effortless listening experience
- Natural and tangible sound due to accurate reproduction of details, creates a believable presentation
- Solid and controlled bass performance, unusual for a 300B single-ended triode amplifier
- Excellent sense of touch and tactile sound, making instruments like plucked strings and bowed violins sound very convincing
- Wide and deep soundstage with good 'air', providing a transparent and 'hear-through' sound, especially with complex music
Product Considerations
- Careful matching with partnering equipment is required, especially speakers with high efficiency
- Relatively low overall gain requires a source with a high output voltage
- Output transformer links need to be correctly set for speaker impedance, requiring dealer assistance
- Some reviewers found the top end sounding a bit rolled off before use of appropriate high efficiency speakers and source gain settings
- Changing the EL803S driver valves requires carefully matched pairs supplied by Thöress
Comparisons (according to reviewers)
- Vs Shindo Haut-Brion/Corton-Charlemagne, Thöress has more treble extension and transparency, Shindo has better upper-bass/lower-midrange substance and body—and more drive
Takeaway: The Thöress SE-300B offers a supremely musical and detailed listening experience with a focus on accuracy and sonic purity. When paired with the right speakers, this amplifier could be an excellent choice to bring out the best in music.
Video review
Our take on the brand
THÖRESS introduces the EHT Mono Amplifier... The most powerful amplifier model of our product line provides 30, 40 or 50 watts of output power into a 8, 6 or 4 ohm load respectively, combined with very low output resistance (high damping factor). Such providing excellent drive capability for loudspeakers with medium to low efficiency or critical impedance behavior. While offering an ultimate sonic presentation without involving exotic and costly power tubes. The amplifier is based on a unique minimalist single-ended zero-feedback hybrid circuit which we call EHT Topology. Basic analysis easily shows that the EHT topology represents the PUREST form of all possible single-ended triode power amplifier configurations.
Our summary
Product Strengths
- The EHT combines tubes and transistors to mate the most desirable characteristics of both
- Amplifiers provide fullness and density, even at low listening volumes
- The EHT creates a natural sound with incredible saturation
- They are fully short-circuit proof at the outputs without any sound-degrading protection
- A switch-on delay is omitted because switching on/off develops no disturbing noise or dangerous signal in this circuit
Product Considerations
- Sound is focused on timbre rather than detail
- Their sound is soft rather than focused, rather warm than open, and rather close to us than presented in a perspective
- The devices are quite large, as they measure 434 x 184 x 434 mm (W x H x D) and weigh 14 kg each
Takeaway: The Thöress EHT monoblocks offer a holistic view of the musical material and its reinterpretation that can be very enjoyable for long listening sessions. They create events in their own acoustic environment, which is completely transferred to the listening room, creating a beautiful, organic, comprehensive, and internally properly arranged sound for those who value tonality above all else.
Video review
Our take on the brand
One of the finest parallel single ended 300B tube amplifier made by Fezz Audio. It provides openness and spatial sound. Powerful, sublime, very involving and uniqe to itself. Fezz Audio Lybra gives you the best sounding experience you can get from the 300B tubes.
Our summary
Product Strengths
- Delivers an incredibly rich, flavorful midrange and a sweet, relaxed treble
- Has a more sophisticated presentation than the utilitarian bent-metal chassis sported by most integrated tube amps on the market, and the smooth lines of the chassis help the amp stand out from the crowd
- Has a clever tube cage design with a clear Plexiglass front panel that delivers an unobstructed view of the tubes and is easy to install and remove
- Is seriously quiet, and there was effectively zero noise through any of the speakers
Product Considerations
- Can sound wildly different, depending on the impedance of the speakers
- The four slightly squishy feet underneath the amp may cause stains
- The power switch is on the rear of the chassis, which may be problematic if installing the amp in a cabinet with limited access
- Needs a good 20 minutes to warm up, and on initial startup, the amp sounded a bit thin, bright, and constipated, but after one album, it opened right up
- Limited power output (15Wpc) may not be sufficient for all speakers or listening preferences, especially when wanting to play music very loud
Takeaway: The Fezz Audio Lybra 300B is a well-designed tube amplifier that delivers a rich and flavorful sound. It can bring out the best in your speakers, offering clarity and great sound.
Video review
Our take on the brand
What competes at this price?
Our Summary
Product Strengths
- Classic single-ended triode amplifier that caresses vocals and conveys warmth in vocal recordings
- Delivers rock-solid image placement and transparency, particularly in the midband
- Acts like a higher-wattage amplifier than its 18W rating suggests
- Can drive speakers that aren't absurdly sensitive
Product Considerations
- Build quality is not as refined as the more expensive Japanese-made Audio Note products
- Bass can be waffly/uncontrolled
- Top-end frequency performance can vary
- May not impress those familiar with higher-end Audio Note amplifiers
Takeaway: The Audio Note Conquest is a single-ended triode amplifier that can provide a lush, sweet midband and is more powerful than its specifications suggest. It offers single-ended triode performance at a more accessible price point.
Video review
Our take on the brand
Our Summary
Product Strengths
- Neutral and transparent sound, more so than the reference amplifier
- Bass performance is remarkably tight, articulate, solid, and weighty, without typical 'tube character'
- Very good rhythmic capabilities
- Maintains control even with inefficient or difficult speakers
- Threads a fine middle path between a typical transistor sound and a typical tube sound—with an unmistakable midrange charm
Product Considerations
- Some might find it 'not characterful enough' because it is superbly even-handed
- With some speakers, the balance can be a little too lean and overly controlled
- Its low power rating ultimately imposes a limit on how loud one can play, which may not suit everyone
Comparisons (according to reviewers)
- Vs Ayon Spirit III: The Lybra sounds almost as powerful and robust in the bass while being perhaps even tighter and articulate, and is more highly refined with subtler and airier treble
- Vs Trafomatic tube amps and MP's Jadis amplifiers: The Lybra offers something different, it's not as voluptuous, rich, and relaxed as the Trafomatic
Takeaway: The Fezz Lybra is a neutral and controlled amplifier that offers a balanced sound without sounding like a typical tube amp, providing articulate bass and a charming midrange. It could be worth buying if you like very good sound, especially if you have efficient speakers.
Video review
Our take on the brand
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Our Summary
Product Strengths
- Metal chassis provides better ergonomics and structural integrity compared to the previous wood chassis
- Robust power supply prevents compression, even with demanding speakers
- Has full bandwidth down into the low 20s without problem
- Warm lush midrange and the right 3d spatial cues up top
- Fast, accurate, proportionate sound that is warm but not dry or analytical
Product Considerations
- The reviewer mentioned they are going to work on adding name badges to the next versions
Takeaway: The amplifier is great sounding with a robust power supply. Its proportionate and warm sound makes it ideal for nearfield listening.
Video review
Our take on the brand
Our Summary
Product Strengths
- Creates an extraordinarily vivid sound
- Has the seeming ability to turn up the contrast knob on everything passed through it
- Offers great color and body
Product Considerations
- When playing very loud passages at extravagant volume levels, it clipped less elegantly
- Bass output was just a bit excessive
Comparisons (according to reviewers)
- Surpasses the Haut-Brion in terms of color saturation
- The Haut-Brion has a somewhat better sense of scale overall, is capable of greater delicacy when needed, and sounded a shade righter, timbrally, on trumpets and singing voices
- The Haut-Brion offered the more well-balanced bass, relative to the volume of sound in the rest of the audible range—the Haut's bass was also drier and a little more detailed
Takeaway: The Shindo Montille CV 391 is a hand-wired tube amp that delivers vivid and colorful sound, making music come alive. It's a great match for less sensitive speakers and offers a unique listening experience.
Video review
Our take on the brand
Our Summary
Product Strengths
- Delivers a holographic soundstage and exceptional mid-range clarity, creating a visceral and nuanced listening experience
- Offers great tonal accuracy and mid-range performance, especially with acoustic and vocal-heavy music
- The amplifier is powerful enough to drive speakers and the reviewer's headphones with ease
- Can be re-tubed with entirely NOS (New Old Stock) tubes for under $300, making it a bargain to maintain compared to other amplifiers
- Has multiple output impedances allowing matching to pretty much any headphone
Product Considerations
- Direct Heated Triodes are naturally more noisy than indirectly heated tubes
- Users with highly sensitive headphones (north of 100dB/mW efficient), like Utopia or Stellia, might experience some background noise
- Bass presentation focuses on detail and texture rather than thick, chest-thumping slam
- Caution should be used when lifting it, as it is much denser than it appears
Comparisons (according to reviewers)
- Vs ampsandsound Nautilus: The Rockwell is more delicate and nuanced, with more space and air, whereas the Nautilus produces greater slam and is more tonally dense
- Vs ampsandsound Kenzie Ovation: There are similarities in tone and vocal rendering, but the Rockwell is more powerful, creating dynamics that explode
- Vs ampsandsound Bigger Ben: The Rockwell provides more low-end detail, while the Bigger Ben reaches slightly lower with more slam
Takeaway: The Rockwell is a seductive and fun amplifier that is worth owning, especially for those who appreciate the classic American hifi sound. It offers a remarkable listening experience and the ability to use affordable NOS tubes.
Video review
Our take on the brand
Questions? Ask the brand's dealers.
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