Yamaha A-U671 Stereo Amplifier with USB DAC Function User Manual

Table of Contents

1. Introduction
2. Package Contents
3. Connections
4. Settings
5. Remote Control
6. Troubleshooting
7. Frequently Asked Questions

1. Introduction

Welcome to the Yamaha A-U671 Stereo Amplifier with USB DAC Function. This high-resolution audio amplifier is designed to provide you with the best sound quality for your TV, movies, and music. With USB DAC functionality, enjoy DSD 5.6 MHz and PCM 384 kHz playback, and embrace a new world of digital audio playback.

2. Package Contents

• Yamaha A-U671 Stereo Amplifier
• Remote Control
• 2 AAA Batteries
• User Manual

3. Connections

Before connecting your devices, ensure that the stereo amplifier is powered off and all devices are unplugged.

1. Connect your speakers to the five-way speaker binding posts. The A-U671 is compatible with bare wire, spades, or banana jacks.
2. Connect your subwoofer to the subwoofer terminal if desired.
3. Connect an analog audio source to the analog audio input (stereo).
4. For high-resolution audio playback, connect your PC or Mac to the USB DAC input using a USB cable.

4. Settings

After connecting your devices, power on the stereo amplifier and configure the settings as desired. For optimal sound quality, use the Pure Direct mode, which bypasses certain circuitry for a cleaner sound. To enable Pure Direct mode, press the Pure Direct button on the front panel or remote control.

5. Remote Control

The included remote control allows for easy operation of your stereo amplifier. To use the remote control, insert the provided AAA batteries and ensure that the remote is within range of the amplifier.

6. Troubleshooting

1. If you experience noise or hissing in the audio output, check all connections and ensure that cables are securely connected.
2. If the amplifier is not recognized by your PC or Mac, ensure that the USB cable is securely connected and that the appropriate drivers are installed. Visit the Yamaha website for the latest drivers.
3. If the LED indicators on the front panel do not light up, check the power connection and ensure that the amplifier is powered on.

7. Frequently Asked Questions

Q: Can I connect additional audio sources to the A-U671?

A: The A-U671 has one analog audio input (stereo) and one USB DAC input. It does not have coaxial, optical, Wi-Fi, Bluetooth, or HDMI inputs.

Q: Does the A-U671 support headphone output?

A: Yes, the A-U671 has a headphone output on the front panel for private listening.

Q: Is the A-U671 compatible with 4-ohm speakers?

A: The A-U671 is rated for 6-ohm speakers, but some users have reported success with 4-ohm speakers. However, performance may vary and is not guaranteed for 4-ohm speakers.

Q: How do I update the firmware on my A-U671?

A: Visit the Yamaha website for the latest firmware updates and follow the provided instructions to update your amplifier.

Q: What is the maximum resolution that this amplifier can play?
A: The Yamaha A-U671 Stereo Amplifier with USB DAC Function can play DSD 5.6 MHz and PCM 384 kHz with high-grade USB DAC functionality.

Q: What type of DAC does this amplifier use?
A: This amplifier utilizes the ESS SABRE32 DAC (ES9010K2M) from the U.S. company, ESS Technology.

Q: How many speaker binding posts does this amplifier have?
A: The A-U671 has five-way speaker binding posts (stereo).

Q: Does this amplifier have an analog audio input?
A: Yes, it has an analog audio input (stereo) and a single subwoofer output.

Q: What is the power output of this amplifier?
A: The power output of the A-U671 is 70 W + 70 W (6 ohms, 1 kHz, 10% THD).

Q: Can this amplifier handle 5 ohm bookshelf speakers?
A: According to a customer review, it handled a pair of bookshelf speakers nominally rated at 4 ohms without any issues.

Q: Is there a phono input on this amplifier?
A: Yes, there is a phono input on this amplifier.

Q: Can this amplifier be connected to a turntable?
A: Yes, it can be connected to a turntable but you'll need to ground the turntable to the amp chassis as there is no dedicated phono ground lug.

Q: Is the remote control made of aluminum or plastic?
A: The remote control is made of plastic.

Q: Does the DAC work with Linux?
A: There is no information provided by Yamaha regarding Linux compatibility.

Q: Will this amplifier drive KEF LS50 speakers?
A: According to a customer review, it drives a pair of KEF Q-100 bookshelf speakers and a small powered sub with no issues.

Q: Does this amplifier work with 220v power?
A: No, the U.S. model has a standard 110 volt plug.

Q: Is there a significant difference in sound quality when using the Pure Direct mode?
A: According to Yamaha, the Pure Direct mode improves audio quality by bypassing certain circuitry. However, a customer review stated that they noticed no difference when compared to playback without it.

Q: What are the pros and cons of this amplifier?
A: Pros include very clean and natural sounding playback, powerful class D amp, capable of driving a wide range of bookshelf speakers to realistic volumes, rock solid firmware/software, bass and treble control knobs, size (small enough to allow for more placement options than a full-size component), and subwoofer pre-out. Cons include limited connection possibilities (only USB and RCA inputs), pricey relative to some full-size amps with more features, power, and connection options.

Q: How does this amplifier compare to the NAD D 3020 integrated amplifier?
A: According to a customer review, this amplifier sounds better than the NAD D 3020 with nice, warm, punchy, clear, detailed sound. The Yamaha A-U671 has more oomph and punchier bass compared to the NAD D 3020's thin, brittle, sterile sound.