Nobsound G2 PRO TPA3255 Hi-Fi 300W Subwoofer Power Amplifier Mono Channel Class D SUB Audio Amp User Manual

Introduction

This manual provides detailed instructions for the proper setup, operation, and maintenance of your Nobsound G2 PRO TPA3255 Hi-Fi 300W Subwoofer Power Amplifier. Please read this manual thoroughly before using the product to ensure optimal performance and safety.

Figure 1: Nobsound G2 PRO TPA3255 Hi-Fi 300W Subwoofer Power Amplifier.

Product Overview

The Nobsound G2 PRO is a versatile mono channel Class D amplifier designed for both full-frequency and subwoofer applications. It features a compact design with powerful output capabilities.

Key Features:

PBTL/SUB Switch: Allows convenient switching between full-frequency amplifier mode and subwoofer amplifier mode. A dedicated SUB output is available for active subwoofers.
High Output Power: Equipped with a TPA3255D2 amplifier chip and a 32V/5A power supply, capable of driving 320W passive speakers or subwoofers.
Gain Adjustment: Features a gain switch for 2-level output level setting (32dB/36dB) to maintain sound quality.
SUB Frequency Adjustment: Adjustable low-pass filter from 40-300Hz for precise subwoofer integration.
Compact Design: Mini-sized, durable solid aluminum chassis suitable for various audio setups.

Controls and Connections:

Nobsound G2 PRO front and rear panel connections

Figure 2: Front and Rear Panel Layout of the G2 PRO Amplifier.

Front Panel:
- Power Light: Indicates power status.
- ON/OFF Switch: Toggles power for the unit.
- PBTL/SUB Switch: Selects between full-frequency (PBTL) and subwoofer (SUB) modes.
  Figure 3: PBTL/SUB Mode Switch.
- SUB FREQ Knob: Adjusts the low-pass filter frequency (40-300Hz) when in SUB mode.
- VOLUME Knob: Controls the overall output volume.
  Figure 4: SUB FREQ and VOLUME Controls.
Rear Panel:
- AUDIO IN (RCA): Stereo RCA inputs for connecting audio sources (e.g., phone, MP3 player, TV/Blu-ray, CD media players, PC/Mac/Computer, Echo Dot, Turntable).
- SUB OUT (RCA): Dedicated RCA output for connecting to an active subwoofer.
- SPEAKER OUT (Binding Posts): Speaker terminals for connecting passive speakers or passive subwoofers.
  Figure 5: Rear Panel Output Terminals.
- DC24V-48V Power Input: Connects to the provided 32V 5A power supply.
Bottom Panel:
- Gain Setting DIP Switches (SW1, SW2): Adjusts the amplifier's gain level.
  Figure 6: Bottom Panel of the G2 PRO, showing gain switches.
  Figure 6a: Close-up of Gain Setting DIP Switches.
  
  Gain Setting Table
  Gain Setting SW1 SW2
  36dB ON ON
  32dB ON OFF

Gain Setting Table
Gain Setting	SW1	SW2
36dB	ON	ON
32dB	ON	OFF

Setup

Follow these steps to set up your Nobsound G2 PRO amplifier.

1. Power Connection:

Ensure the amplifier's ON/OFF switch is in the OFF position.
Connect the provided 32V 5A power supply to the DC24V-48V input on the rear panel of the amplifier.
Plug the power supply into a suitable wall outlet.

2. Audio Input Connection:

Connect your audio source (e.g., smartphone, computer, CD player) to the AUDIO IN RCA ports on the rear panel using appropriate RCA cables.

3. Speaker Output Connection:

The G2 PRO can be configured for different speaker setups:

3.1. 2.0 Channel Setup (Using two G2 PRO units for stereo):

For a stereo setup, two Nobsound G2 PRO units are required. Each unit will drive one channel (left or right) independently, minimizing mutual interference.

Diagram for 2.0 channel setup with two Nobsound G2 PRO amplifiers

Figure 7: 2.0 Channel Stereo Setup Diagram.

Connect the left channel output from your audio source to the AUDIO IN of the first G2 PRO unit.
Connect the right channel output from your audio source to the AUDIO IN of the second G2 PRO unit.
Connect your left passive speaker to the SPEAKER OUT terminals of the first G2 PRO unit.
Connect your right passive speaker to the SPEAKER OUT terminals of the second G2 PRO unit.
Ensure both G2 PRO units are set to PBTL (full-frequency) mode using the front panel switch.

3.2. 2.1 Channel Setup (with active or passive subwoofer):

The G2 PRO can be integrated into a 2.1 channel system. The diagram below illustrates two common methods.

Diagram for 2.1 channel setup with Nobsound G2 PRO amplifier

Figure 8: 2.1 Channel Setup Diagrams (Way 1 & Way 2).

Way 1: Using one G2 PRO for full-frequency speakers and SUB output for active subwoofer.
1. Connect your audio source to the AUDIO IN of the G2 PRO.
2. Connect your passive full-range speakers to the SPEAKER OUT terminals of the G2 PRO.
3. Connect the SUB OUT of the G2 PRO to the input of your active subwoofer.
4. Set the G2 PRO to PBTL (full-frequency) mode. The SUB output will still function.
Way 2: Using multiple G2 PRO units for full-frequency and passive subwoofer.
This setup requires an audio switcher/splitter with multiple outputs or a DIY audio input cable to split the signal.
1. Connect your audio source to an audio switcher/splitter.
2. Connect the split audio signals to the AUDIO IN of two G2 PRO units for left/right full-range speakers (set to PBTL mode).
3. Connect another split audio signal to the AUDIO IN of a third G2 PRO unit for the passive subwoofer (set to SUB mode).
4. Connect the respective passive speakers/subwoofer to the SPEAKER OUT terminals of each G2 PRO unit.

4. Gain Adjustment:

The G2 PRO has gain setting DIP switches on its bottom panel. Adjust these switches (SW1 and SW2) to select between 32dB and 36dB gain settings based on your audio source's output level and desired volume.

Refer to the "Gain Setting Table" in the "Product Overview" section for switch configurations.

Operating Instructions

Once all connections are made, you can begin operating your Nobsound G2 PRO amplifier.

1. Powering On/Off:

Flip the ON/OFF switch on the front panel to the "ON" position to power on the amplifier. The power light will illuminate. Flip it to "OFF" to power down.

Video 1: Demonstration of Nobsound G2 PRO setup and basic operation, including power on/off and volume adjustment.

2. Selecting Operating Mode:

Use the PBTL/SUB switch on the front panel to select the desired operating mode:

PBTL (Full-Frequency) Mode: For driving full-range passive speakers. The amplifier will output the full audio spectrum.
SUB (Subwoofer) Mode: For driving passive subwoofers. The amplifier will apply a low-pass filter, allowing only low frequencies to pass through.

Note: The dedicated SUB OUT RCA port for active subwoofers functions regardless of the PBTL/SUB switch setting, allowing simultaneous output of SUB signal and amplified audio.

3. Volume Control:

Rotate the VOLUME knob clockwise to increase the volume and counter-clockwise to decrease it. Start with a low volume and gradually increase it to a comfortable listening level.

4. Subwoofer Frequency Adjustment (SUB Mode only):

When the amplifier is in SUB mode, use the SUB FREQ knob to adjust the crossover frequency for the subwoofer. This allows you to fine-tune the bass response and seamlessly integrate your subwoofer with your main speakers.

Maintenance

Proper maintenance ensures the longevity and optimal performance of your Nobsound G2 PRO amplifier.

Cleaning: Use a soft, dry cloth to clean the exterior of the amplifier. Do not use liquid cleaners or aerosols, as they may damage the finish or internal components.
Ventilation: Ensure the amplifier is placed in a well-ventilated area to prevent overheating. Do not block any ventilation openings.
Storage: If storing the amplifier for an extended period, disconnect it from power and store it in a cool, dry place away from direct sunlight and extreme temperatures.
Connections: Periodically check all cable connections to ensure they are secure. Loose connections can lead to poor sound quality or intermittent operation.

Troubleshooting

If you encounter issues with your Nobsound G2 PRO amplifier, refer to the following common problems and solutions:

Problem	Possible Cause	Solution
No sound output	Power not connected or unit off. Incorrect input/output connections. Volume too low. Audio source issue. Incorrect mode selected (PBTL/SUB).	Ensure power supply is connected and unit is ON. Verify all audio input and speaker output cables are correctly and securely connected. Increase the VOLUME knob. Check if the audio source is playing and its volume is adequate. Ensure the PBTL/SUB switch is in the correct position for your speakers.
Distorted sound	Volume too high. Incorrect gain setting. Poor quality audio source. Speaker impedance mismatch.	Decrease the VOLUME knob. Adjust the gain setting on the bottom panel (try 32dB if currently at 36dB). Test with a different audio source. Ensure speakers are 4 ohms or higher (as per product specifications).
No bass (in SUB mode)	SUB FREQ knob set too low. Subwoofer not connected or powered.	Increase the SUB FREQ knob. Verify active subwoofer is powered on and connected to SUB OUT, or passive subwoofer is connected to SPEAKER OUT and G2 PRO is in SUB mode.
Unit feels warm	Normal operation. Insufficient ventilation.	A slight warmth is normal for Class D amplifiers. Ensure adequate airflow around the unit. Do not place it in an enclosed space.

Specifications

Detailed technical specifications for the Nobsound G2 PRO amplifier:

Feature	Specification
Brand	Nobsound
Model Number	DZ072_UK
Output Power	Max 300W (into 4 ohms)
Number of Channels	1 (Mono)
Amplifier Chip	TPA3255D2
Minimum Supply Voltage	24 Volts (DC)
Maximum Supply Voltage	35 Volts (Recommended 32V/5A power supply included)
Supply Current	5 Amps (with included power supply)
Subwoofer Frequency Adjustment	40-300Hz
Gain Settings	32dB / 36dB (adjustable via DIP switches)
Package Dimensions	10.08 x 8.46 x 2.6 inches
Item Weight	1.1 pounds

Nobsound G2 PRO with 300W output power label and power supply

Figure 9: Max 300W Output Power Capability.

Nobsound G2 PRO held in hand showing its mini size

Figure 10: Compact Size of the G2 PRO Amplifier (Dimensions: 127*35*118mm).

What's in the Box

The Nobsound G2 PRO package includes the following items:

Packing list for Nobsound G2 PRO showing amplifier and power supply

Figure 11: Package Contents.

1 x Nobsound G2 PRO Amplifier
1 x 32V 5A Power Supply

Warranty and Support

For warranty information and technical support, please refer to the official Nobsound/Douk Audio website or contact their customer service. Contact information may also be found on the product packaging.

Nobsound G2 PRO product box with contact information

Figure 12: Product Packaging with Contact Information.

Official Website: www.doukaudio.com

Email: nobsound@doukaudio.com

For further assistance, you may also visit the Nobsound Store on Amazon.

Nobsound DZ072_UK