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.
Product Strengths
- Fully balanced technology, with balanced inputs and outputs.
- Delivers powerful amplification, with up to 7.5 watts of power, capable of driving a wide range of headphones, including hard-to-drive models.
- Features a linear power supply with a large transformer and capacitor bank, providing a stable and powerful power source.
- Provides two current modes (50mA and 100mA) to tailor the sound tonality, allowing users to choose between a more forward/analytical sound and a warmer/fuller sound.
- Employs an R2R network for volume control, ensuring channel balance even at low volumes.
Product Considerations
- Runs quite hot due to its Class A amplification, requiring adequate ventilation, with chassis temperatures potentially reaching up to 50 degrees Celsius, and the unit may switch from 100mA to 50mA mode if it overheats.
- High power output might not be ideal for very sensitive IEMs, potentially limiting volume control flexibility.
- The preamplifier output is always active, meaning it doesn't mute when headphones are plugged in, requiring caution to prevent damage.
- The LCD display cannot be dimmed or switched off, and the red color of the 100mA mode may appear washed out.
- Some report volume slots are not regular or have large jumps, and/or that the remote control can be buggy.
Comparisons (according to reviewers)
- Vs. Topping A90 Discrete: The S17 has a richer sound, wider soundstage, and easier dynamics, especially in 100mA mode, placing it in a higher tier.
- Vs. Topping A90D: The S17 Pro is capable of even stronger dynamic swings, with a slightly cleaner and less cluttered soundstage.
- Vs. Violectric V222: The Aune S17 Pro is more 'tubey' and warmer sounding than the V222.
- Vs. HIFIMAN EF600: The Aune S17 has better volume control, higher dynamic range, better driving power, and better resolution.
Takeaway: The Aune S17 Pro is a powerful and versatile headphone amplifier that delivers rich, detailed sound, allowing listeners to experience music in new ways. With its balanced design and flexible current modes, it can enhance a wide range of headphones and audio setups.
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.
BU1-Portable-DAC-with-Headphone-Amplifier
- Positioning: Entry-level design focused on portability and affordability.
- Description: Offers a compact DAC and headphone amplifier suited for on-the-go audio setups and small room use, with a straightforward design that meets basic connectivity needs. Compared to other models, it has fewer advanced controls and processing options, making it ideal for users with a limited budget and simple functionality requirements.
Yuki-USB-DAC-with-Headphone-Amp
- Positioning: Budget-friendly desktop solution designed for streamlined USB audio performance.
- Description: Features a clear USB input interface and precise DAC circuitry that provide improved sound clarity for desktop listening. Compared to the portable BU1 and more feature-rich models, it addresses basic needs at a modest cost while offering reliable performance for everyday use.
X1s-GT-X1s-GT-BT-DAC-with-Headphone-Amp
- Positioning: Mid-range option offering a blend of wired and wireless connectivity for versatile setups.
- Description: Integrates both Bluetooth and digital inputs in a robust DAC/amp package that supports varied audio sources, making it adaptable for home or portable applications. Compared to the entry-level designs, it provides better build quality and added connectivity without reaching premium price levels.
X8-XVIII-X8-XVIII-BT-Magic-DAC
- Positioning: Advanced model featuring a unique Bluetooth transmission system for enhanced digital audio.
- Description: Introduces a proprietary BT Magic feature that improves wireless connectivity and digital conversion quality, making it a notable upgrade in performance for modern audio setups. Compared to lower-priced models, it delivers superior digital-to-analog conversion and connectivity features while still being positioned below the top-tier S9c Pro.
S9c-Pro-DAC-with-Headphone-Amp-with-AL3-XLR-Balanced-Male-to-Female-3-Pin-Audio-Cable-1-Pair
- Positioning: Premium high-end solution optimized for balanced outputs and precise audio reproduction.
- Description: Uses advanced DAC circuits and balanced amplifier outputs that provide superior audio detail and technical refinement. Compared to every other model in the lineup, it offers more versatile connectivity options and a higher standard of build quality.
Read the reviews

Manufacturer's notes
- Weight: 4.7 kg (10.3617 lb = 165.7876 oz)
Our take on the brand
What if you spend a bit more?

Our Summary
Product Strengths
- Delivers a vividly detailed and balanced sound, handling complicated mixes with skill
- Able to extract a lot of information from digital audio files with apparent ease
- A volume lock prevents accidental volume adjustments when the device is in a pocket or bag
- Extensive specification including Bluetooth 5.4 with aptX Lossless compatibility and multiple inputs/outputs for versatile connectivity
Product Considerations
- Some reviewers feel the device is not very pocket-friendly due to its size and sharp edges, making it better suited as a transportable—rather than a truly portable—device
- The gain is set too high, making precise volume control difficult, especially with sensitive IEMs
- Using IEMatch adds output impedance, which can negatively affect the tonal balance and dynamics of some IEMs
- The length of the included USB-C cable is short, making it difficult to position the device on a desk
Comparisons (according to reviewers)
- Compared to the iDSD Diablo 1, the Diablo 2 offers slight sonic improvements and better build quality, but at a higher price
- Compared to the iDSD Signature, the iDSD Signature is considered by some to offer a better result for less money, with a more realistic instrument and vocal timbre, larger soundstage, and customizable features like crossfeed and bass boost
- Compared to the FiiO Q7, the iDSD Diablo 2 has a vivid sound, where the FiiO Q7 has a smooth and wide sound
Takeaway: The iDSD Diablo 2 is a powerful and versatile DAC/amp that enhances headphone listening with its detailed sound and extensive features. It is a good choice for users who want a high-quality audio experience on the go or at their desk.
Video review
Our take on the brand

When our HYPSOS won an EISA award in 2021, we knew we were on the right track and went on to follow our dreams of delivering the best possible audio gear we could think of. When we learned OOR was chosen by the honorable EISA members as best Headphone Amplifier of 2022-2023, all our dreams came true. As did HYPSOS, OOR is a ground-up design without precedent, created from a profound exploration of analogue audio in its purest form. Understated looks married with sophisticated power delivery and amplifier technologies, delivering ultra-low distortion, huge dynamics and unrivaled detail. For those who want to go even further in unleashing unheard musicality, OOR is, of course, designed to pair perfectly with the HYPSOS Hybrid Power System.
Our Summary
Product Strengths
- Compact size compared to competitors, allowing for easy integration into desktop setups
- The OOR outputs 8 watts of power at 60 ohms and 1.6 watts at 300 ohms, making it one of the most powerful headphone amplifiers ever made
- Low gain setting is silent with sensitive IEMs
- Employs a fully discrete class AB amplifier; there are no op-amps used
Product Considerations
- Simultaneous use of the balanced and single-ended preamp outputs with the main headphone output is an inconvenience
- The unit gets quite warm after a few hours of use—recommending a well-ventilated area
- Powering on the unit requires going from balanced to single-ended
Comparisons (according to reviewers)
- Vs Benchmark HPA4, OOR felt considerably more alive, fleshed out, and natural sounding
- Vs Flux Volot, the reviewers felt that the OOR was more visceral sounding
- Compared to Fluxlab Acoustics, the OOR is a warmer and more soul-infusing amplifier and it never wants to be linear or flat
- Vs Flux Lab Acoustics Volod, it was easily bigger sounding, easily more impressive sounding, just more layered
Takeaway: The Ferrum OOR is a powerful amplifier in a small package, and it is built with great attention to detail. It has an engaging sound with a touch of warmth.
Video review
Our take on the brand

Our Summary
Product Strengths
- Wonderfully enjoyable and transparent sound, described as smooth, resolving, and engaging, enhancing music without coloration
- Open design makes it easy to swap out the tubes
- It opens the soundstage in depth and width, increasing the ability to hear the placement of instruments, and micro details and spatial cues become more accessible
- Versatile, the Velo works well with different headphones (low/high impedance, dynamic/planar)
Product Considerations
- Not particularly powerful, the Velo might require more volume dial rotation compared to other amps to reach desired listening levels
- Bass might sound a little too rounded and lacking texture compared to some setups
- Lacks balanced XLR features
- The included switching power supply is not at the same performance level as the upgraded linear power supply
Comparisons (according to reviewers)
- Vs Linear Tube Audio MZ3: The MZ3 is more resolving and detailed, while the Velo is richer and smoother, the MZ3 is more technically engaging, but the Velo is more emotionally engaging
- Vs Burson Soloist 3X-GT: The Soloist 3X-GT has more power and greater resolution/clarity with a balanced cable, but the Velo is more intimate and relaxing
- Vs Oliver Sayes Type 26 DHT preamplifier: The Velo strikes a nice middle ground between the overly 'emotional' tube stage and the 'straight' sounding TVC mode
- Vs Eddie Current Zana Deux SE OTL: Unlike the Zana Deux, it doesn't go too far in warmth to the point of sounding mushy
Takeaway: The Velo is a versatile tube amplifier that provides a wonderful and enjoyable listening experience by being transparent and smooth. It's designed for music lovers who value emotional engagement with their music.
Video review
Our take on the brand

Our Summary
Product Strengths
- Compact form factor with a massive choice of connections and functions, including 4 headphone outputs: 4-pin XLR balanced, 4.4mm balanced jack, 6.35mm, and 3.5mm
- Very clean, neutral sound with a lot of dynamics, slam, and punch
- Plenty of power to drive any pair of headphones with ease
- Very detailed and resolving sound, exacting and precise about its reproduction, revealing of the DAC plugged into it
- Well-designed and built with durable feel
Product Considerations
- The input selector does not remember the previous setting
- Higher noise floor compared to competitors, making it less suitable for extremely sensitive headphones and most IEMs
- The pre-out and the headphone out work at the same time, so be careful
- The LED, even though it's only white, is not super bright, but its brightness cannot be changed
Comparisons (according to reviewers)
- Mytek Liberty THX is more exacting, detailed, resolving, and more neutral than HeadAmp GSX Mini, and the GSX Mini rounds things a little bit more and has a slightly bit more of warmth to things
- Mytek Liberty THX is better than the Topping A90, music is more alive and better articulated, more detailed, and the background is blacker
- With HE1000v2, Mytek Liberty THX is exceptionally clear and tight-sounding—imaging is probably the best it sounds
Takeaway: The Mytek Liberty THX AAA HPA is a powerful and compact headphone amplifier delivering very clean, neutral, and detailed sound suitable for a wide range of headphones. It could be a reference-grade, exacting amplifier.
Video review
Our take on the brand
What else competes at this price?

Our Summary
Product Strengths
- Improved battery management offering faster charging rates and better efficiency than its predecessor
- Features a new USB-C data input for greater flexibility alongside other inputs
- Offers the world's first lossless DSP for tone adjustments without degrading sound quality, providing customization options
- Excellent resolution and dynamics with a large soundstage and extreme detail
Product Considerations
- The Mojo 2 can get warm when in a pocket for a period of time
- Complicated menu navigation with color-coded buttons that may require the manual
- Still uses Micro-USB for charging, which some find outdated
Takeaway: The Chord Mojo 2 is an exceptional DAC/headphone amplifier for those seeking high-resolution audio and customized sound in a portable format that is easy to move. Its sonic accuracy, detailed soundstage, and improved features provide a versatile and enjoyable listening experience, making it a worthwhile consideration for audio enthusiasts.
Video review
Our take on the brand

Our Summary
Product Strengths
- Versatile connectivity with both wireless (Bluetooth 5.1 with various codecs) and wired options (USB, S/PDIF, analog inputs) makes it suitable for various setups—from desktop to portable usage
- Eloquent, informative, and entertaining sound quality, able to produce clear, non-artificial sound across different headphones
- Features such as XBass II and XSpace provide additional sound shaping options for the user to customize the sound to their liking
- The aluminum build provides a robust and premium feel, with a design that's described as sleek and comfortable to handle
Product Considerations
- The user interface is not very intuitive
- Decent headphones are needed to reveal its quality
- The OLED screen can be difficult to read
- Battery life is around six to eight hours
Comparisons (according to reviewers)
- Compared to the hip-dac2, the Gryphon offers better sound quality, more features, and flexibility
- Compared to the iFi GO bar, the Gryphon is bigger and has a built-in battery, and the GO bar is much smaller and draws power from the source device
- Compared to the iDSD Diablo, the Diablo has more power for very demanding headphones, Gryphon has more functions
- Compared to the Zen DAC, the xDSD Gryphon has a more sophisticated and detailed sound
Takeaway: The iFi xDSD Gryphon is a portable and versatile device delivering high-quality sound with extensive features that cater to audiophiles. Its ability to improve sound quality from various sources and its robust build make it a worthwhile investment for music lovers on the go.
Video review
Our take on the brand

Our Summary
Product Strengths
- Very clean, smooth, and enjoyable sound without harsh edges or digitization
- Plenty of power for a wide range of headphones and IEMs due to its 3.8 watts into a 32 ohm load
- Comes with a linear power supply that provides clean power and minimizes noise
- Includes a remote control that can also control the matching DAC
- Offers versatile connectivity with balanced and single-ended pre-outputs, as well as multiple line inputs
Product Considerations
- 4.4mm connections are used for balanced input/output, which may require purchasing new cables if existing XLR cables are already owned
- The VU meter on the front of the device may not be very useful for normal listening levels
- Settings are not held when the amplifier is turned off
- There is noise in headphones when the unit is turned off or on from standby mode
Comparisons (according to reviewers)
- Vs Burson Audio Soloist 3XP: Champ provides more body and weight to the sound, while the Soloist 3XP offers greater space and separation
Takeaway: The CH-Amp is a compact and versatile amplifier that delivers a clean and enjoyable sound, making it a great choice for those looking for a high-quality listening experience. Its ability to pair well with a variety of headphones and IEMs makes it a worthwhile addition to any setup.
Video review
Our take on the brand

Our Summary
Product Strengths
- Unique and engaging musical experience, even with some hard-to-drive headphones
- Natural, fluid, musical sound with a bit of warmth, superb soundstage, and resolution
- Exceptional detail for the price category and low distortion
- Great build quality and a pleasing aesthetic, being hand-built
- Also works as a preamplifier for stereo setups
Product Considerations
- Not designed for planar magnetic headphones or for low impedance headphones
- May sound brighter, with lower bass quantity and precision, with low impedance headphones
- Tubes are consumables and will burn out after a couple thousand hours of use
- The power switch is located on the back, which some may find inconvenient
Comparisons (according to reviewers)
- Vs SPL Audio Phonitor 2 amp—Echo 2 provides a more refined experience
- Vs Hagerman Tuba—Echo 2 has better driving power and clarity for high impedance headphones
- Vs Audio-gd Master 19—Echo 2 has a more natural tonality and deeper soundstage for high impedance headphones
- Vs Violectric HPA V340—Echo 2 has a more magical musicality and a smoother presentation for high impedance headphones
- Vs Burson Soloist 3X Performance—Echo MKII leans towards a slightly more relaxed sound, while Soloist leans into a more forward aggressive one, and the Soloist has stronger treble extension
Takeaway: The Feliks Audio Echo 2/MKII is a great tube amplifier for those who appreciate engaging and emotionally rich listening sessions, especially with high-impedance dynamic headphones. This hand-built amplifier offers a unique musicality and adds warmth and depth to music.
Video review
Our take on the brand

Our Summary
Product Strengths
- Very sturdy and well-built headphone amplifier made out of aluminum
- Plenty of power and driving capabilities for both high impedance headphones and low impedance planars
- Tonality is well balanced with nothing emphasized or lacking across the frequency spectrum
- Sounds very natural and coherent, with no edgy or rough parts in its performance
- Offers good detail retrieval, separation, and layering of instruments and vocals
Product Considerations
- As a preamp, sound staging isn't particularly wide or deep compared to dedicated preamps
- The black volume knob is described as plasticky and some reviewers wish it was silver to match the chassis
- Lacks a 12V trigger, which would be a much-needed option
- Can run hot
- No auto-standby mode
Comparisons (according to reviewers)
- Vs Topping A90D: SH-X adds a slight hint of warmth in the bass section and is slightly more alive–engaging sounding, while A90D sounds more ruler flat
- Vs aune S17 Pro: SH-X can compete head to head with S17 Pro in 50mA mode, but S17 Pro edges it out in 100mA mode sounding tonally richer and fuller
Takeaway: The SMSL SH-X is a beautifully built and powerful headphone amplifier that offers a clean and transparent sound. It is a great choice for those wanting a high-performing amplifier with versatile connectivity options.
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.
Product Strengths
- Fully balanced technology, with balanced inputs and outputs.
- Delivers powerful amplification, with up to 7.5 watts of power, capable of driving a wide range of headphones, including hard-to-drive models.
- Features a linear power supply with a large transformer and capacitor bank, providing a stable and powerful power source.
- Provides two current modes (50mA and 100mA) to tailor the sound tonality, allowing users to choose between a more forward/analytical sound and a warmer/fuller sound.
- Employs an R2R network for volume control, ensuring channel balance even at low volumes.
Product Considerations
- Runs quite hot due to its Class A amplification, requiring adequate ventilation, with chassis temperatures potentially reaching up to 50 degrees Celsius, and the unit may switch from 100mA to 50mA mode if it overheats.
- High power output might not be ideal for very sensitive IEMs, potentially limiting volume control flexibility.
- The preamplifier output is always active, meaning it doesn't mute when headphones are plugged in, requiring caution to prevent damage.
- The LCD display cannot be dimmed or switched off, and the red color of the 100mA mode may appear washed out.
- Some report volume slots are not regular or have large jumps, and/or that the remote control can be buggy.
Comparisons (according to reviewers)
- Vs. Topping A90 Discrete: The S17 has a richer sound, wider soundstage, and easier dynamics, especially in 100mA mode, placing it in a higher tier.
- Vs. Topping A90D: The S17 Pro is capable of even stronger dynamic swings, with a slightly cleaner and less cluttered soundstage.
- Vs. Violectric V222: The Aune S17 Pro is more 'tubey' and warmer sounding than the V222.
- Vs. HIFIMAN EF600: The Aune S17 has better volume control, higher dynamic range, better driving power, and better resolution.
Takeaway: The Aune S17 Pro is a powerful and versatile headphone amplifier that delivers rich, detailed sound, allowing listeners to experience music in new ways. With its balanced design and flexible current modes, it can enhance a wide range of headphones and audio setups.
Want to see more similar products?
Head on over to our Search page to browse our entire database. Find the perfect hifi gear for your system.