Douk Audio VU56 PRO User Manual

1. Introduction

The Douk Audio VU56 PRO is an advanced sound level meter and audio splitter designed for precise audio level monitoring and visual display. It features a 56-bit per channel LED music spectrum display, offering high resolution and real-time visualization of audio signals. This device supports both PPM (peak programme meter) and VU (volume unit) modes, making it suitable for various professional and recreational audio applications. Additionally, it functions as an audio converter/splitter with multiple input and output options, controlled conveniently via an included remote.

2. Safety Information

• Ensure the device is powered by a DC 5V (≥1A) Micro USB power supply. Using an incorrect power supply may damage the unit.
• Do not expose the device to water, moisture, or extreme temperatures.
• Avoid placing the device in direct sunlight or near heat sources.
• Do not attempt to disassemble or modify the device. Refer all servicing to qualified personnel.
• Keep the device away from strong magnetic fields.
• Handle the remote control with care. Ensure the correct battery type (CR2025) is used if replacement is needed.

3. Package Contents

Verify that all items are present in the package:

• 1x Douk Audio VU56 PRO Sound Level Meter
• 1x Remote Control
• 1x USB Cable (for power)
• 1x 3.5mm AUX Cable
• 1x User Manual

4. Product Overview

4.1 Front Panel

The front panel features the primary LED display, showing audio levels for both left and right channels. The display provides a visual representation of the audio signal's dynamics.

Figure 4.1: Front view of the VU56 PRO with active LED display.

4.2 Rear Panel

The rear panel houses all input and output connections, along with the power input and mode selection switch.

Figure 4.2: Rear panel connections and controls.

• RCA / AUX Input (LINE 1 IN): For connecting audio sources via RCA or 3.5mm AUX.
• RCA / AUX Output (LINE 1 OUT): For connecting to amplifiers or active speakers.
• LINE 2 IN / OUT: Additional RCA/AUX input/output, connected in parallel with LINE 1.
• MODE Switch: Toggles between MIC (microphone) and LINE input modes.
• ON/OFF Switch: Power switch.
• Microphone Pick-up Hole: Built-in microphone for ambient sound level detection.
• USB IN: Micro USB port for DC 5V power input.

Note: The inputs and outputs of LINE 1 and LINE 2 are connected in parallel. Only one set of inputs and outputs should be connected at a time to avoid signal conflicts.

5. Setup

1. Power Connection: Connect the provided USB cable to the "USB IN" port on the rear panel of the VU56 PRO. Connect the other end of the USB cable to a DC 5V (≥1A) power adapter (not included) or a compatible USB port.
2. Audio Input Connection:
   • Line Input (RCA/AUX): If using an audio source like a CD player, MP3 player, computer, or phone, connect it to the "LINE 1 IN" or "LINE 2 IN" RCA/3.5mm AUX ports using the appropriate audio cable. Ensure the MODE switch is set to "LINE".
   • Microphone Input: If monitoring ambient sound, ensure the MODE switch is set to "MIC". The built-in microphone will pick up sound from the environment.
3. Audio Output Connection (Optional): If using the VU56 PRO as an audio splitter, connect the "LINE 1 OUT" or "LINE 2 OUT" RCA/3.5mm AUX ports to your amplifier or active speakers.
4. Power On: Flip the ON/OFF switch on the rear panel to the "ON" position. The LED display should illuminate.

6. Operating Instructions

The VU56 PRO is primarily controlled using the included remote control. Ensure the remote has a CR2025 battery installed.

Figure 6.1: VU56 PRO with remote control.

6.1 Display Modes (PPM / VU)

The VU56 PRO supports two main display modes:

• PPM Mode (Peak Programme Meter): 0dB = 1.5Vpp. Recommended for general dynamic display.
• VU Mode (Volume Unit): 0dB = 0.775Vrms. More suitable for professional audio level monitoring.

Switch between modes using the remote control (refer to remote button functions below).

Figure 6.2: VU56 PRO displaying in PPM (top) and VU (bottom) modes.

6.2 Remote Control Functions

The remote control allows adjustment of various display parameters:

• Power Button: Turns the device on/off.
• Brightness Adjustment: Adjusts the LED display brightness (4 levels).
• Display Color Switch: Toggles between green and red display colors for the main bar and peak LED.
• Display Effects: Selects from 8 different display effects.
• Display Length Gain: Adjusts the display sensitivity (-3dB, 0dB, +3dB).
• Peak LED Holding Time: Adjusts how long the peak LED remains illuminated.
• Drop Speed: Controls the speed at which the main bar and peak LED drop.
• Mode Selection: Dedicated buttons for PPM and VU mode selection.

All settings adjusted via the remote control are saved automatically, even after the device is powered off.

Figure 6.3: Examples of 8 different display effects.

7. Specifications

Figure 7.1: Display calibration values for 0dB, -3dB, and +3dB.

8. Maintenance

• Cleaning: Use a soft, dry cloth to clean the exterior of the device. Do not use liquid cleaners or aerosols.
• Storage: Store the device in a cool, dry place away from direct sunlight and extreme temperatures when not in use for extended periods.
• Remote Battery: Replace the CR2025 battery in the remote control when its performance degrades.

9. Troubleshooting

10. Warranty and Support

Douk Audio products are designed for reliability and performance. For warranty information and technical support, please refer to the official Douk Audio website or contact their customer service directly. Keep your purchase receipt as proof of purchase for any warranty claims.

For further assistance, please visit: www.doukaudio.com