Nobsound A3 Hi-Fi Vacuum Tube Amplifier Instruction Manual

Introduction

Thank you for purchasing the Nobsound A3 Hi-Fi Vacuum Tube Amplifier. This amplifier is designed to deliver a rich and warm audio experience with versatile connectivity options. This manual provides essential information for the proper setup, operation, and maintenance of your device to ensure optimal performance and longevity.

What's in the Box

Carefully unpack the contents and ensure all items are present:

• 1 x Nobsound A3 Amplifier
• 1 x Power Cord
• 1 x Remote Control

Image: The Nobsound A3 amplifier shown with its power cord and remote control, illustrating the contents of the package.

Product Overview

Front Panel Controls and Indicators

Image: Detailed view of the amplifier's front panel, highlighting the power switch, input select switch, input channel indicators (IR, Coaxial, Optical, Bluetooth, CD, DVD, USB), 6.5mm headphone output, VU meter, USB input, previous/next song buttons, and volume knob.

1. IR Receiver: For remote control signals.
2. Power Switch: Toggles the amplifier on or off.
3. Input Select Switch: Cycles through available audio inputs.
4. Input Channel Indicators: LEDs illuminate to show the currently selected input (COAX, OPT, BT, CD, DVD, USB).
5. 6.5mm Headphone Output: Connect headphones for private listening.
6. VU Meter: Displays audio signal levels.
7. USB Input: Connect a USB drive for direct audio playback.
8. Previous/Next Song Buttons: For controlling playback from USB or Bluetooth sources.
9. Volume Knob: Adjusts the overall output volume.

Rear Panel Connections

Image: Detailed view of the amplifier's rear panel, showing the subwoofer output, speaker outputs (FR, FL), optical input, coaxial input, two sets of RCA inputs (CD, DVD), and the AC power input with voltage selector switch.

1. Subwoofer Output (SW.OUT): Connects to an active subwoofer.
2. Speaker Output (FR/FL): Connects to passive stereo speakers.
3. Optical Input (OPT): Connects to devices with optical digital audio output.
4. Coaxial Input (COAX): Connects to devices with coaxial digital audio output.
5. RCA Inputs (CD/DVD): Two sets of stereo RCA inputs for analog audio sources.
6. AC Power Input: Connects the power cord. Includes a voltage selector switch (110V/220V).

Setup

1. Power Connection

• Before connecting the power cord, ensure the voltage selector switch on the rear panel is set to your local power supply (AC 110V 60Hz or AC 220V 50Hz).
• Connect the provided power cord to the AC Power Input on the rear panel of the amplifier and then to a wall outlet.

2. Speaker Connection

• Connect your passive stereo speakers to the Speaker Output terminals (FR for Front Right, FL for Front Left) on the rear panel. Ensure correct polarity (+ to + and - to -) for each speaker.

3. Subwoofer Connection (Optional)

• If using an active subwoofer, connect it to the Subwoofer Output (SW.OUT) on the rear panel using an RCA cable.

4. Audio Input Connections

Choose one of the following input methods:

• Bluetooth: No physical connection needed. See 'Operating Instructions' for pairing.
• Optical/Coaxial: Connect a digital audio cable from your source device (e.g., TV, CD player) to the OPT or COAX input on the amplifier.
• RCA: Connect analog audio cables from your source device (e.g., CD player, DVD player, turntable with pre-amp) to one of the RCA inputs (CD or DVD) on the amplifier.
• USB: Insert a USB flash drive containing audio files into the USB Input on the front panel.

5. Headphone Connection (Optional)

• Connect your headphones to the 6.5mm Headphone Output jack on the front panel for private listening.

Operating Instructions

1. Power On/Off

• Press the Power Switch on the front panel to turn the amplifier on or off. The vacuum tubes will glow when powered on.

2. Input Selection

• Press the Input Select Switch on the front panel to cycle through the available audio inputs (COAX, OPT, BT, CD, DVD, USB). The corresponding LED indicator will light up.

3. Volume Control

• Rotate the Volume Knob on the front panel clockwise to increase volume and counter-clockwise to decrease volume.
• The VU meter will visually indicate the audio signal level.

Image: A close-up view of the amplifier's VU meter, which provides a visual representation of the audio output level.

4. Bluetooth Pairing

• Select the BT input using the Input Select Switch. The Bluetooth indicator will flash.
• On your mobile device, search for Bluetooth devices and select "Nobsound A3" to pair.
• Once paired, the Bluetooth indicator will remain solid.

5. USB Playback

• Insert a USB flash drive into the USB Input on the front panel.
• Select the USB input. The amplifier will automatically begin playing compatible audio files.
• Use the Previous/Next Song Buttons to navigate tracks.

6. Remote Control Usage

• The included remote control allows for convenient operation of power, input selection, volume adjustment, and USB/Bluetooth playback controls from a distance.
• Ensure the remote is pointed towards the IR receiver on the amplifier's front panel.

Image: The Nobsound A3 amplifier positioned with its remote control, illustrating the convenience of remote operation for various functions.

Maintenance

General Care

• Keep the amplifier in a well-ventilated area to prevent overheating.
• Avoid exposing the unit to direct sunlight, high temperatures, humidity, or dust.
• Clean the exterior with a soft, dry cloth. Do not use liquid cleaners or solvents.
• Ensure the vacuum tubes are free from dust. Handle tubes with care as they can be fragile.

Image: A close-up view of the illuminated vacuum tubes, emphasizing their delicate nature and the need for careful handling during maintenance.

Tube Replacement

• Vacuum tubes have a finite lifespan. If sound quality degrades or a tube fails, replacement may be necessary.
• Always power off and unplug the amplifier before attempting to replace tubes. Allow tubes to cool completely.
• Gently pull the old tube straight up from its socket. Align the pins of the new tube with the socket holes and push it gently but firmly into place.
• Refer to the manufacturer for compatible replacement tube types.

Troubleshooting

If you encounter issues, consult the following table before seeking professional assistance:

Specifications

The following are the general specifications for the Nobsound A3 amplifier:

• Model: A3
• Manufacturer: Nobsound
• Package Dimensions: 12.75 x 9.5 x 8.5 inches
• Item Weight: 7.72 pounds
• First Available: May 25, 2023
• Inputs: Bluetooth 5.0, USB, Coaxial, Optical, 2x RCA (CD, DVD)
• Outputs: Speaker (2-channel), Subwoofer (active), 6.5mm Headphone Jack

Image: A diagram illustrating the physical dimensions (length, width, height) and weight of the Nobsound A3 amplifier, along with its power cord and remote control.

Warranty and Support

For warranty information, technical support, or service inquiries, please contact Nobsound directly or refer to the documentation provided at the time of purchase. Additional protection plans may be available for purchase separately.