Yamaha A-U671: Elevating Audio Excellence


In today’s fast-paced world, where music has become an integral part of our lives, the demand for high-quality sound amplification has never been greater. Whether you are a music enthusiast, a professional musician, or simply someone who appreciates the beauty of crystal-clear audio, having a reliable and powerful amplifier is essential. In this review, we will be delving into the world of hifi sound amplification and exploring the features and performance of the Yamaha A-U671 amplifier.

The Yamaha A-U671 is a versatile and technologically advanced amplifier that promises to deliver an exceptional audio experience. With its sleek design and robust construction, this amplifier is built to impress both visually and sonically. It boasts a range of features that are designed to enhance your listening pleasure and provide you with a truly immersive sound experience.

Whether you are using it for home entertainment purposes or as part of a professional setup, the Yamaha A-U671 amplifier is sure to meet your needs. Its ability to reproduce high-resolution audio with remarkable clarity and precision makes it a standout choice in the market. With its wide frequency response range and impressive signal-to-noise ratio, this amplifier ensures that every note and every nuance of your favorite tracks are faithfully reproduced.

In the following sections of this review, we will delve deeper into the technical specifications, design, functionality, sound characteristics, and performance of the Yamaha A-U671 amplifier. We will explore its advantages and evaluate its value for money. By the end of this review, you will have a comprehensive understanding of what sets this amplifier apart from its competitors and whether it is the right choice for you.

So sit back, relax, and join us on this journey as we uncover the wonders of the Yamaha A-U671 amplifier and discover how it can elevate your audio experience to new heights.

Technical Specifications

The Yamaha A-U671 amplifier offers impressive technical specifications that contribute to its exceptional audio performance. With a power output of 70 watts per channel at 6 ohms, this integrated amplifier is capable of driving powerful speaker systems. The amplifier utilizes a digital power amplifier based on analog type Pulse Width Modulation (PWM) to ensure natural and uncolored sound reproduction.

In terms of sound quality, the Yamaha A-U671 boasts a signal-to-noise ratio (SNR) of 95 dB, indicating a high level of clarity and minimal background noise. Additionally, the amplifier has a low total harmonic distortion (THD), ensuring that the audio signal remains faithful to the original source without any unwanted distortion.

This amplifier offers a variety of inputs and outputs to accommodate different audio sources. It features a built-in USB digital-to-analog converter (DAC) that supports high-resolution audio formats, including DSD Native 5.6 MHz and PCM up to 384 kHz/32-bit. The inclusion of a USB input allows for seamless connectivity with digital devices, such as computers, providing a direct and pure audio signal.

The Yamaha A-U671 also provides stereo RCA line inputs for connecting analog sources, offering versatility in connecting various audio components. Additionally, it features a headphone output on the front panel, allowing for personal listening with high-quality sound reproduction.

In terms of frequency response, this amplifier covers a wide range from 10 Hz to 40 kHz, ensuring accurate reproduction of both low and high-frequency sounds. With an impedance of 6 ohms, it is compatible with a wide range of speaker systems.

Overall, the technical specifications of the Yamaha A-U671 highlight its ability to deliver high-resolution audio and provide versatile connectivity options. Its power output, low distortion, and wide frequency response make it an excellent choice for audiophiles seeking exceptional sound quality.

Design and Construction

The Yamaha A-U671 amplifier boasts a sleek and modern design that is sure to catch the eye of any audio enthusiast. The amplifier has a compact and slim profile, with dimensions of 314mm in width, 342mm in depth, and 70mm in height. Its black color adds a touch of elegance to any audio setup.

The construction of the amplifier is top-notch, showcasing Yamaha’s commitment to quality. The materials used in its construction are of high quality, ensuring durability and longevity. The amplifier feels solid and well-built, giving users confidence in its performance.

One notable design feature of the Yamaha A-U671 is its efficient cooling system. The amplifier is designed with proper ventilation to prevent overheating during prolonged use. This ensures that the amplifier operates at optimal temperatures, reducing the risk of damage and maintaining consistent performance.

In terms of reducing interference, Yamaha has implemented measures to minimize electrical noise and distortion. The amplifier features a well-designed layout that separates the power supply section from the audio circuitry. This helps to reduce any potential interference that could affect the audio quality.

The connectors and switches on the Yamaha A-U671 are of excellent quality. The amplifier is equipped with a variety of inputs and outputs, including stereo RCA inputs and a dedicated subwoofer output. These connectors provide a secure and reliable connection for various audio devices. Additionally, the switches on the front panel are sturdy and responsive, allowing for easy control and adjustment of settings.

Overall, the design and construction of the Yamaha A-U671 amplifier showcase Yamaha’s attention to detail and commitment to providing a high-quality product. Its sleek appearance, durable construction materials, efficient cooling system, and reliable connectors make it a standout choice for audiophiles seeking both style and performance in their audio setup.


The Yamaha A-U671 amplifier offers a wide range of functionality to cater to various audio sources and preferences. With its versatile connectivity options, you can easily connect CD players, computers, smartphones, and other devices to enjoy your favorite music.

One notable feature is the availability of balance controls and tone adjustments, allowing you to customize the sound according to your preferences. Whether you prefer a more bass-heavy or treble-focused sound, the amplifier gives you the flexibility to fine-tune the audio output.

Additionally, the amplifier offers different operating modes to enhance your listening experience. The Pure Direct mode allows you to bypass tone controls and balance adjustments, delivering a clean and unaltered signal from input to output. This mode is ideal for audiophiles who prefer a purist approach to sound reproduction.

Furthermore, the Yamaha A-U671 amplifier includes a built-in USB player, enabling easy playback of digital audio files directly from a USB device. This feature eliminates the need for additional equipment and simplifies the process of enjoying high-quality music.

Overall, the functionality of the Yamaha A-U671 amplifier ensures seamless integration with various audio sources while providing ample control options for personalized sound adjustments. Whether you are a casual listener or an avid audiophile, this amplifier offers versatility and convenience in meeting your audio needs.

Sound Characteristics

The Yamaha A-U671 amplifier delivers exceptional sound characteristics that will impress even the most discerning audiophiles. With its high resolution and ability to reproduce the original quality of the source, this amplifier ensures a truly immersive sound experience.

One notable aspect of the sound quality is its impressive instrument separation. Each instrument and vocal can be heard with clarity and precision, creating a rich and detailed audio presentation. This level of detail allows for a more immersive listening experience, where you can pick up on subtle nuances and appreciate the intricacies of each musical element.

The bass response of the Yamaha A-U671 is powerful and well-defined. It offers a deep and tight low-end, adding depth and impact to your music. Whether you’re listening to bass-heavy genres like EDM or enjoying the smooth grooves of jazz, the amplifier reproduces the bass frequencies with accuracy and authority.

The treble clarity of this amplifier is remarkable. It provides crisp and clear highs without any harshness or distortion. The delicate details in the upper frequencies are well-preserved, allowing for an enjoyable listening experience across various music genres.

Overall, the sound presentation of the Yamaha A-U671 is captivating. It strikes a perfect balance between warmth and accuracy, delivering a natural and engaging soundstage. Whether you’re listening to classical symphonies or rocking out to energetic rock anthems, this amplifier enhances the audio quality, bringing out the best in every genre.

In conclusion, the Yamaha A-U671 excels in its sound characteristics by offering exceptional instrument separation, powerful bass response, clear treble, and an overall captivating sound presentation. It allows you to fully immerse yourself in your favorite music genres, providing an enjoyable and high-quality listening experience.

Sound Performance

The Yamaha A-U671 amplifier delivers an exceptional sound performance that will truly captivate any audiophile. With its high-resolution capabilities, this amplifier excels at faithfully reproducing the original quality of audio signals, providing an immersive auditory experience like no other.

The clarity of the sound produced by the A-U671 is truly remarkable. Every intricate detail and nuance of the music is brought to life with precision and accuracy. From the delicate whispers of a violin to the thunderous beats of a bass drum, this amplifier ensures that every note is heard with utmost clarity.

Furthermore, the dynamics of the sound are incredibly impressive. The A-U671 has the ability to effortlessly transition between soft and gentle passages to powerful and energetic crescendos, capturing the full range of emotions within the music. Whether you’re listening to a classical symphony or a rock anthem, this amplifier ensures that you feel every rise and fall in intensity.

One of the standout features of the A-U671 is its impeccable tonal balance across different frequency ranges. The lows are rich and impactful, providing a solid foundation for the music. The mids are warm and smooth, allowing vocals and instruments to shine through with exceptional detail. The highs are crisp and clear, adding sparkle and brilliance to the overall sound.

Regardless of the genre or style of music you prefer, the Yamaha A-U671 amplifier delivers a sound performance that will leave you in awe. Its ability to faithfully reproduce audio signals with clarity, dynamics, and tonal balance sets it apart from other amplifiers in its class. Whether you’re a casual listener or a dedicated audiophile, you can trust that this amplifier will provide an unparalleled listening experience.

In conclusion, the sound performance of the Yamaha A-U671 amplifier is nothing short of extraordinary. Its ability to accurately reproduce audio signals with clarity, dynamics, and tonal balance makes it a standout choice for any music lover. With this amplifier, you can truly immerse yourself in the music and appreciate every detail with a level of fidelity that is unmatched.


The Yamaha A-U671 amplifier offers several advantages that set it apart from its competitors in the market. Firstly, its high-resolution capability allows for the faithful reproduction of the original audio quality. With a USB-DAC supporting DSD 5.6 MHz, this amplifier provides compatibility with the latest digital audio sources, ensuring a seamless integration into the modern world of high-resolution music.

One significant advantage of the A-U671 is its digital power amplifier based on analog type Pulse Width Modulation (PWM). This technology enables natural and uncolored sound reproduction, delivering a wide dynamic range from delicate and quiet passages to powerful and energetic sounds. With a power output of up to 70 watts per channel, this amplifier is capable of driving even powerful speaker systems, making it suitable for various listening environments.

The inclusion of a low-loss, low-distortion low-pass filter in the final stage significantly influences the sound quality. This large coil made of oxygen-free copper wire enhances bass response, adds warmth to mid and high frequencies, and ensures purity in high-resolution source signals. Additionally, the Pure Direct switch allows for direct signal transmission from input to output, bypassing tone control circuits and buffer stages, resulting in cleaner sound reproduction.

Another advantage of the A-U671 is its high-quality built-in USB-DAC that supports DSD Native 5.6 MHz and PCM 384 kHz formats. The 32-bit 2-channel digital-to-analog converter (DAC) utilizes the SABRE 32 (ES9010K2M) chip by ESS Technology with an integrated USB controller from XMOS. This combination ensures clean playback and optimal sound quality by reducing noise through asynchronous transmission.

Furthermore, this amplifier can also be used as a high-quality headphone amplifier when connected to a computer. It maximizes the quality of high-resolution source signals, providing a pure and immersive listening experience through your favorite headphones.

When compared to other models in the same price range, the Yamaha A-U671 stands out with its exceptional build quality, advanced features, and superior audio performance. It offers a compelling combination of power, versatility, and high-resolution capabilities that make it a standout choice for audiophiles and music enthusiasts.

In conclusion, the Yamaha A-U671 amplifier excels in various aspects, including its high-resolution capability, natural sound reproduction, versatile functionality, and superior build quality. With its powerful performance and advanced features, it offers excellent value for money when compared to other amplifiers in its price range. Whether you’re a music lover or an audiophile seeking a premium audio experience, the Yamaha A-U671 is a worthy investment that will elevate your listening pleasure to new heights.

Value for Money

The Yamaha A-U671 amplifier offers excellent value for money with its impressive performance, extensive features, and competitive price point. This amplifier provides a high-resolution audio experience, allowing users to enjoy the original quality of their music sources.

With its built-in USB-DAC supporting DSD 5.6MHz and PCM 384kHz formats, the A-U671 ensures compatibility with the latest digital audio sources. This feature alone sets it apart from other amplifiers in its price range, as it allows for playback of high-resolution audio files with exceptional clarity and detail.

Furthermore, the A-U671 boasts a powerful digital power amplifier that delivers up to 70 watts per channel, capable of driving even demanding speaker systems. The analog-type pulse width modulation (PWM) technology employed in this amplifier ensures natural and uncolored sound reproduction across a wide dynamic range.

In terms of connectivity options, the A-U671 offers a variety of inputs and outputs, including a USB input for connecting to computers or external storage devices, stereo RCA inputs for connecting analog sources, and a headphone output conveniently located on the front panel. While it may lack internet connectivity features like AirPlay or Bluetooth, the inclusion of a USB input and headphone output makes it versatile for various listening scenarios.

Considering its technical specifications and robust performance capabilities, the Yamaha A-U671 provides exceptional value compared to other amplifiers in its class. Its ability to reproduce high-resolution audio with precision and deliver ample power to speakers makes it an attractive choice for both audiophiles and casual listeners alike.

When comparing its price to similar amplifiers on the market, the A-U671 stands out as an affordable option without compromising on quality or features. The inclusion of a built-in USB-DAC alone justifies its value proposition as it eliminates the need for an external DAC device.

Overall, the Yamaha A-U671 offers incredible value for money by delivering outstanding audio performance, versatile functionality, and advanced features at a competitive price point. Whether you are a music enthusiast or a casual listener, this amplifier provides an immersive and enjoyable listening experience without breaking the bank.


In conclusion, the Yamaha A-U671 amplifier is a high-quality and versatile audio device that offers impressive performance and functionality. With its sleek design, robust construction, and user-friendly interface, it is a great addition to any audio setup.

The technical specifications of the amplifier showcase its capabilities, including a power output of 70W per channel, a wide frequency range of 10Hz to 40kHz, and a high signal-to-noise ratio of 95dB. These specifications ensure clear and accurate sound reproduction across various genres and audio sources.

The design and construction of the Yamaha A-U671 are both elegant and sturdy. The compact size allows for easy placement in any space, while the black color adds a touch of sophistication. The inclusion of a remote control enhances convenience, allowing users to adjust settings from a distance.

Functionality-wise, this amplifier excels with its built-in USB DAC that supports DSD 5.6MHz and PCM 384kHz formats. This feature ensures compatibility with modern digital audio sources and delivers exceptional audio quality with high resolution. Additionally, the Pure Direct switch bypasses unnecessary circuitry for a purer sound experience.

When it comes to sound characteristics, the Yamaha A-U671 impresses with its natural and uncolored sound reproduction. The analog-based digital power amplifier provides a wide dynamic range, allowing for nuanced playback from soft passages to powerful crescendos. The low-loss low-pass filter enhances bass response while maintaining clarity in mid and high frequencies.

In terms of sound performance, this amplifier truly shines. It delivers detailed and immersive audio across various music genres, bringing out the subtleties in each track. Whether you’re listening through speakers or headphones, the Yamaha A-U671 ensures an enjoyable listening experience with its high-resolution capabilities.

The advantages of the Yamaha A-U671 include its high-resolution USB DAC, versatile connectivity options such as RCA inputs and headphone output, as well as its compact and stylish design. It offers excellent value for money, considering its impressive performance and feature set.

For potential buyers, the Yamaha A-U671 is an ideal choice if you prioritize high-quality audio reproduction, compatibility with digital sources, and a sleek design. Whether you’re a music enthusiast or an audiophile, this amplifier delivers exceptional sound performance and versatility.

In conclusion, the Yamaha A-U671 amplifier is a top-notch audio device that combines outstanding sound quality, modern features, and elegant design. Its ability to reproduce high-resolution audio, along with its user-friendly functionality, makes it a compelling choice for discerning listeners. With its impressive performance and reasonable price point, the Yamaha A-U671 offers excellent value for money.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top