Douk Audio P1 Vacuum Tube Preamplifier User Manual

1. Introduction

The Douk Audio P1 is a versatile vacuum tube preamplifier designed to enhance your audio experience. It functions as a Hi-Fi tube preamp, USB DAC, and headphone amplifier, delivering clear, warm, dynamic, and sweet tube sound. This manual provides essential information for the proper setup, operation, and maintenance of your P1 preamplifier.

Figure 1.1: Douk Audio P1 Vacuum Tube Preamplifier.

2. Safety Information

• Do not expose the device to water or excessive moisture.
• Avoid placing the device in direct sunlight or near heat sources.
• Ensure proper ventilation around the unit to prevent overheating.
• Do not attempt to disassemble or repair the unit yourself. Refer to qualified personnel for service.
• Use only the provided power adapter.
• Keep out of reach of children.

3. Package Contents

Please check the package for the following items:

• Douk Audio P1 Preamplifier
• Power Adapter
• USB Cable
• GE5654 Vacuum Tubes (pre-installed or included separately)
• Bluetooth Antenna

Figure 3.1: P1 Preamplifier and typical accessories.

4. Product Overview

4.1 Front Panel

Figure 4.1: Front Panel Layout.

• Power Switch: Turns the unit on/off.
• Bluetooth Indicator: Illuminates when Bluetooth is active.
• Input Mode Switch (SELECT): Toggles between BT (Bluetooth), USB, and RCA inputs.
• TONE Switch: Enables or disables the Bass and Treble tone controls. When OFF, the tone knobs are bypassed.
• LED Light Color Select/Off (LED): Changes the color of the tube illumination (Blue/Orange) or turns it off.
• Bass Knob: Adjusts low-frequency response.
• Main Volume Knob: Controls the overall output volume.
• Treble Knob: Adjusts high-frequency response.
• 3.5mm Headphone Output: Connects to headphones (does not support headphones with microphone TRRS port).

4.2 Rear Panel

Figure 4.2: Rear Panel Layout.

• PC-USB Input: Connects to a computer for USB DAC functionality.
• BT Antenna Port: Connects the included Bluetooth antenna.
• RCA Input (R/L): Connects to audio sources via RCA cables.
• RCA Output (R/L): Connects to power amplifiers or active speakers.
• DC12V Power Input: Connects the power adapter.

5. Setup

5.1 Tube Installation

If the GE5654 vacuum tubes are not pre-installed, carefully insert them into their sockets on the top panel. Ensure the pins align correctly with the socket holes. Apply gentle, even pressure until the tubes are fully seated.

Figure 5.1: GE5654 Vacuum Tubes.

5.2 Connecting Audio Sources and Outputs

1. Connect Output: Connect the RCA Output (R/L) of the P1 to your power amplifier or active speakers using RCA cables.
2. Connect Audio Source:
   • Bluetooth: Screw the Bluetooth antenna into the BT Antenna Port on the rear panel.
   • USB: Connect the PC-USB input to your computer using the provided USB cable.
   • RCA: Connect your audio source (e.g., CD player, TV, MP3 player) to the RCA Input (R/L) using RCA cables.
3. Connect Power: Connect the power adapter to the DC12V Power Input and then plug it into a wall outlet.

Figure 5.2: Example Bluetooth Setup.

6. Operating Instructions

1. Power On: Press the Power Switch on the front panel. The tubes will begin to glow.
2. Select Input: Use the Input Mode Switch (SELECT) to choose your desired audio source: BT (Bluetooth), USB, or RCA.
3. Bluetooth Pairing: If BT is selected, the Bluetooth indicator will flash. On your device (e.g., smartphone), search for "Douk Audio P1" and pair. The indicator will become solid blue once connected.
4. Adjust Volume: Rotate the Main Volume Knob to control the output level. Start with a low volume and gradually increase it.
5. Tone Control: Use the TONE switch to enable (ON) or disable (OFF) the Bass and Treble knobs. Adjust the Bass and Treble knobs to fine-tune the sound to your preference.
6. Headphone Use: Plug your headphones into the 3.5mm Headphone Output. The main RCA output will typically mute when headphones are connected.
7. LED Color: Use the LED switch to cycle between blue, orange, or off for the tube illumination.

7. Maintenance

7.1 Cleaning

Wipe the unit with a soft, dry cloth. Do not use liquid cleaners or abrasive chemicals.

7.2 Tube Replacement

The GE5654 vacuum tubes have a finite lifespan. If you notice a degradation in sound quality or if a tube fails, they can be replaced. Ensure the unit is powered off and unplugged before attempting to replace tubes. Carefully pull the old tubes straight up from their sockets and insert new ones, aligning the pins correctly.

Figure 7.1: Vacuum Tube Detail.

8. Troubleshooting

9. Specifications

10. Warranty and Support

For warranty information and technical support, please refer to the official Douk Audio website or contact their customer service directly. Keep your purchase receipt for warranty claims.

Official Douk Audio Store: Visit Store