FX-AUDIO- DAC-SQ5J+ High-Resolution DAC Instruction Manual

1. Introduction

The FX-AUDIO- DAC-SQ5J+ is a high-performance, high-quality Digital-to-Analog Converter (DAC) designed to deliver superior audio fidelity. It incorporates the renowned Burr-Brown PCM1794A DAC chip and features the SAVITECH BRAVO-HD SA9123L USB receiver chip, enabling high-resolution audio playback up to 24-bit/192kHz via USB. This model is an enhanced version of the highly-regarded DAC-SQ5J, utilizing premium components throughout its design. It offers versatile connectivity with three digital input options: USB, optical, and coaxial, making it compatible with various digital audio sources such as personal computers, CD players, and televisions.

2. Safety Precautions

Ensure the power adapter used is DC12V / 1A or higher, with a 5.5mm outer diameter and 2.1mm inner diameter plug (center positive). Using an incorrect power supply can damage the unit and void the warranty.
Do not expose the unit to water, moisture, or extreme temperatures.
Avoid placing the unit in direct sunlight or near heat sources.
Do not open the casing or attempt to repair the unit yourself. This will void the warranty and may result in electric shock.
Keep out of reach of children.
Disconnect the power adapter from the wall outlet if the unit will not be used for an extended period.

3. Package Contents

Please check that all items are present in the package:

FX-AUDIO- DAC-SQ5J+ Unit
Instruction Manual (this document)

Note: An AC power adapter (DC12V / 1A or higher, center positive) is required for operation and is sold separately.

4. Product Overview

4.1 Front Panel

Front view of the FX-AUDIO- DAC-SQ5J+ showing the power button, select button, and display.

Image: Front view of the DAC-SQ5J+ unit. It features a power button, a 'SELECT' button for input switching, and a display screen showing the current input and sample rate.

POWER Button: Press to turn the unit on or off.
SELECT Button: Press to cycle through the available digital inputs (USB, Optical, Coaxial).
Display: Shows the currently selected input source and the audio sample rate.

4.2 Rear Panel

Rear view of the FX-AUDIO- DAC-SQ5J+ showing USB, Optical, Coaxial, RCA outputs, and power input.

Image: Rear view of the DAC-SQ5J+ unit. From left to right, it shows the USB Type-B input, Optical input, Coaxial input, Stereo RCA analog outputs (R and L), and the DC 12V power input.

USB Input (Type-B): Connect to a computer or other USB audio source.
OPTICAL Input: Connect to an optical digital audio source.
COAXIAL Input: Connect to a coaxial digital audio source.
ANALOG OUTPUT (RCA L/R): Connect to an amplifier, powered speakers, or other analog audio equipment.
POWER (DC 12V): Connect the DC12V power adapter (sold separately).

5. Setup

5.1 Connecting Audio Sources

Choose your desired digital audio source (PC, CD player, TV, etc.).
Connect the digital output of your source device to one of the DAC-SQ5J+'s digital inputs (USB, Optical, or Coaxial) using the appropriate cable.

5.2 Connecting to an Amplifier/Speakers

Connect the RCA L/R analog outputs of the DAC-SQ5J+ to the analog inputs of your amplifier or powered speakers using RCA cables.

5.3 Power Connection

Connect a DC12V / 1A or higher AC power adapter (sold separately) to the POWER input jack on the rear panel of the DAC-SQ5J+.
Plug the power adapter into a wall outlet.

5.4 Driver Installation (for older Windows OS)

For Windows 10 (Creators Update v1703 build 15063 or later), Windows 11, and MacOS X 10.6.4 or later, the unit operates with standard OS drivers and typically requires no additional driver installation.

For older Windows operating systems (Windows 7, Vista, XP, 2000), a dedicated driver installation is required for USB connection. Please download the driver from the official NFJAPAN website: https://nfjapan/driver/sa9123.zip

6. Operating Instructions

Power On: Press the POWER button on the front panel. The display will light up.
Input Selection: Press the SELECT button repeatedly to cycle through the available digital inputs (USB, Optical, Coaxial). The display will indicate the currently selected input.
Audio Playback: Start playing audio from your selected source device. The DAC-SQ5J+ will automatically detect the sample rate and display it.
Power Off: Press the POWER button again to turn off the unit.

7. Maintenance

Clean the unit with a soft, dry cloth. Do not use liquid cleaners or abrasive materials.
Ensure proper ventilation around the unit to prevent overheating.
Keep the unit free from dust and debris.

8. Troubleshooting

Problem	Possible Cause	Solution
No sound output	Incorrect input selected. Cables not connected properly. Power adapter not connected or faulty. Amplifier/speakers not powered on or set to incorrect input.	Press the SELECT button to choose the correct input. Check all audio and power cable connections. Ensure the power adapter is securely connected and functional. Verify your amplifier/speakers are on and set to the correct input.
USB input not recognized by PC	Driver not installed (for older Windows OS). USB cable issue. PC port issue.	Install the necessary driver for older Windows OS (refer to Section 5.4). Try a different USB cable. Connect to a different USB port on your PC. Restart your PC.
Distorted or noisy audio	Poor quality power supply. Interference from other devices. Faulty cables.	Use a high-quality, stable DC12V power adapter. Move the unit away from potential sources of electromagnetic interference. Try replacing audio cables.

9. Specifications

Brand	FX-AUDIO-
Model Number	DAC-SQ5J+
Color	Black
Digital Inputs	USB Type-B (USB1.1/2.0 compatible), Optical (square), Coaxial
Analog Output	Stereo RCA
Supported Format	PCM 2ch Stereo, Max 24bit 192kHz
S/N Ratio	109dB
Dynamic Range	110dB
Total Harmonic Distortion	<0.004% (20Hz-20kHz)
Channel Separation	>99dB
DAC IC	Texas Instruments Burr-Brown PCM1794A
USB Receiver IC	SAVITECH BRAVO-HD SA9123L
Audio Receiver IC	Cirrus Logic CS8416 (DIR)
I/V Conversion Op-Amp	Texas Instruments LM4562 x2
Single-Ended Conversion Op-Amp	Texas Instruments LM4562
Power Supply	DC12V / 1A or more recommended (AC adapter sold separately)
Power Connector	Outer diameter 5.5mm, Inner diameter 2.1mm (center positive)
Dimensions (W×D×H)	98mm × 148mm × 33mm (excluding protrusions)
Weight	332g
Operating OS (USB)	Windows 11/10/8(8.1)/7/Vista/XP/2000, MacOS X/9.1 or later. USB Audio Class 2.0 compatible for Windows 10 Creators Update (v1703 build 15063 or later) and Mac OS X 10.6.4 or later. Standard OS drivers for Windows 10+ and MacOS. Driver installation required for older Windows OS. Mobile OS devices are not guaranteed to work.

10. Warranty and Support

10.1 Product Warranty

This product comes with a 6-month warranty from the date of purchase. Please retain your proof of purchase for warranty claims.

Important Notes:

The AC power adapter is sold separately and is not covered under the product warranty.
Replacement of operational amplifiers (op-amps) by the user is not covered under warranty.
Damage caused by improper use, unauthorized modification, or failure to follow instructions will void the warranty.

10.2 Customer Support

For technical support or warranty inquiries, please contact your retailer or the official FX-AUDIO- support channel. Refer to the contact information provided at the point of purchase or on the official brand website.

FX-AUDIO- DAC-SQ5J+