TOPPING E2x2 OTG USB Audio Interface User Manual

1. Introduction

The TOPPING E2x2 OTG USB Audio Interface is a high-performance device designed for recording, monitoring, and streaming audio with exceptional clarity. It features ultra-linear preamps, a powerful headphone amplifier, and versatile connectivity options for PC, Mac, iOS, and Android devices. This manual provides detailed instructions to help you set up and operate your E2x2 OTG interface effectively.

Figure 1.1: TOPPING E2x2 OTG USB Audio Interface (Black)

Figure 1.2: Key Features of the E2x2 OTG Interface

Key Features:

• High-Quality USB Audio Interface with Optical Output (192kHz/24bit)
• Ultra-Linear Mic Preamp with Ultra-Low Noise (-130.5dBu EIN)
• Powerful Headphone Amplifier (NFCA-LE module, 580mW x 2 @ 32 Ohm)
• Dual Mobile Streaming Capabilities
• Zero-Latency Monitoring and Independent Mixer Control
• 48V Phantom Power Support
• Versatile Compatibility: Windows, Mac, iOS, Android

Product Overview Video:

2. Package Contents

Please verify that all items listed below are included in your package. If any items are missing or damaged, please contact TOPPING customer support.

Figure 2.1: Package Contents Diagram

• TOPPING E2x2 OTG Audio Interface Unit
• USB-A to USB-C Cable
• USB-C to USB-C Cable
• 6.35mm to 3.5mm Adapter
• Quick Start Guide (PDF version available online)

3. Setup and Connections

Follow these steps to connect your TOPPING E2x2 OTG audio interface to your devices and audio equipment.

3.1 Connecting to a Computer (PC/Mac)

Use the provided USB-C to USB-C cable or USB-A to USB-C cable to connect the E2x2 OTG to your computer. The interface will draw power and transmit audio data via this connection. For optimal performance, ensure your computer's USB port can provide sufficient power. If using a standard USB-A port, an additional USB-C power cable may be required for stable operation.

Figure 3.1: Connecting to a Laptop (White Unit)

Figure 3.2: Connecting to a Laptop (Black Unit)

3.2 Connecting to Mobile Devices (iOS/Android)

The E2x2 OTG supports direct connection to mobile devices for recording and dual streaming. Use the OTG port on the rear panel with an appropriate USB-C cable for your mobile device.

Figure 3.3: Mobile Device and Accessory Connections

Figure 3.4: Dual Mobile Streaming Setup

3.3 Audio Input Connections

• Microphones: Connect XLR microphones to the IN1 L and IN2 R combo jacks. Activate 48V phantom power for condenser microphones using the dedicated 48V buttons.
• Instruments: Connect instruments (e.g., guitar, bass) to the IN1 L and IN2 R combo jacks using 1/4" TS cables. Press the INST button to engage instrument mode for high-impedance inputs.

3.4 Audio Output Connections

• Headphones: Plug your headphones into the 6.35mm headphone jack on the front panel.
• Line Outputs: Connect studio monitors or external amplifiers to the LINE OUT (1L, 2R) 6.35mm TRS jacks on the rear panel.
• Optical Output: Use the OPTICAL OUT port for digital audio connection to compatible devices.
• AUX Output: The AUX OUT (3.5mm TRS) provides an additional stereo output.

4. Operating the E2x2 OTG

4.1 Front Panel Controls

Figure 4.1: Front Panel Controls Overview

• MON (Monitor) Knobs: Adjust the input gain for each channel (IN1 L and IN2 R).
• 48V Buttons: Activate/deactivate 48V phantom power for condenser microphones.
• INST Buttons: Toggle between line-level and instrument-level input for each channel.
• Level Meters: Display input and output signal levels. Aim for levels that are strong but do not clip (red indicators).
• MONITOR Knob: Controls the overall volume of the main monitor outputs.
• INPUT/PLAYBACK Blend Knob: Mixes the direct input signal with the playback signal from your computer/mobile device for zero-latency monitoring.
• GAIN Button: Toggles between different gain settings for the headphone amplifier.
• Headphone Volume Knob: Adjusts the volume of the headphone output.
• POWER/OTG Indicators: Show power status and OTG connection status.

4.2 Rear Panel Connections

Figure 4.2: Rear Panel Connections Overview

• Power Switch: Turns the unit on or off.
• POWER (USB-C) Port: For external power supply if needed (e.g., when using with non-USB-C devices or for stable power).
• USB-C Port (For PC): Main data and power connection to your computer.
• OTG Port (For Smartphone/Tablet): Dedicated port for mobile device connectivity.
• OPTICAL OUT: Digital audio output.
• AUX OUT (3.5mm TRS): Auxiliary stereo output.
• LINE OUT (6.35mm TRS): Balanced line outputs for connecting to studio monitors or other audio equipment.

4.3 Software Control (TOPPING Professional Control Center)

The E2x2 OTG comes with dedicated control software that allows for advanced audio routing and mixing. This software provides features such as:

• Multiple simultaneous mixers
• Virtual playback routing options
• Loopback functionality for streaming and recording computer audio
• Detailed input and output level adjustments

Figure 4.3: TOPPING Professional Control Center Software

4.4 Analog Volume Control

The E2x2 OTG features an analog potentiometer for precise volume control of both the Line Out and the headphone amplifier. This ensures accurate and smooth adjustment of your audio levels.

Figure 4.4: Analog Volume Control

5. Maintenance

To ensure the longevity and optimal performance of your TOPPING E2x2 OTG audio interface, follow these maintenance guidelines:

• Cleaning: Use a soft, dry cloth to wipe the exterior of the unit. Avoid using abrasive cleaners, solvents, or strong chemicals, as they may damage the finish.
• Storage: When not in use for extended periods, store the interface in a cool, dry place away from direct sunlight and extreme temperatures.
• Handling: Handle the unit with care. Avoid dropping it or subjecting it to strong impacts.
• Ventilation: Ensure proper ventilation around the unit to prevent overheating. Do not block any vents.

6. Troubleshooting

If you encounter issues with your TOPPING E2x2 OTG, please refer to the following common troubleshooting steps. For more detailed solutions, consult the full user manual PDF linked in the Warranty & Support section.

Common Issues and Solutions:

• No Sound Output:
  • Check all cable connections (USB, headphones, line outputs).
  • Ensure the E2x2 OTG is selected as the default audio output device in your computer's or mobile device's sound settings.
  • Verify that volume knobs on the interface and your connected devices are turned up.
  • Check the input/playback blend knob for proper monitoring mix.
• Distorted Audio:
  • Reduce input gain to prevent clipping (check level meters).
  • Ensure correct instrument/line input settings (INST button).
  • Check sample rate and buffer size settings in your DAW or system audio settings.
• 48V Phantom Power Not Working:
  • Ensure the 48V button is pressed and illuminated for the correct input channel.
  • Verify that your microphone requires phantom power.
• Connectivity Issues (PC/Mobile):
  • Try a different USB port or cable.
  • Restart your computer or mobile device.
  • Ensure necessary drivers are installed for Windows (Mac/iOS/Android are typically class-compliant).
  • For mobile, ensure the OTG connection is stable and your device supports USB OTG audio.

7. Specifications

8. Warranty and Support

8.1 Product Warranty

The TOPPING E2x2 OTG USB Audio Interface comes with a 2-year warranty from the date of purchase. This warranty covers manufacturing defects and ensures reliable performance under normal use. Please retain your proof of purchase for warranty claims.

8.2 Customer Support

For technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact TOPPING customer support through their official channels. You can also refer to the comprehensive PDF user manual for more detailed information:

Download Official User Manual (PDF)