Willsenton R-800i Tube Integrated Amplifier User Manual

1. Introduction

The Willsenton R-800i is a high-fidelity, single-ended Class A integrated and power amplifier designed for exceptional audio performance. It features a hand-welded point-to-point main circuit and utilizes high-quality components, including Z11 iron core output transformers and high-efficiency toroidal power transformers. This amplifier incorporates a selection of vacuum tubes to deliver a rich and detailed sound experience.

This manual provides essential information for the safe and optimal operation of your Willsenton R-800i amplifier. Please read it thoroughly before use and retain it for future reference.

2. Safety Information

• Electrical Safety: Always connect the amplifier to a grounded power outlet. Do not expose the unit to rain or moisture. Disconnect the power cord before cleaning or servicing.
• Heat: Vacuum tubes generate significant heat. Ensure adequate ventilation around the amplifier. Do not place objects on top of the unit that could obstruct airflow. Keep children and pets away from the hot tubes.
• Tube Handling: Tubes are fragile. Handle them with care, especially during installation or replacement. Avoid touching hot tubes.
• Servicing: Refer all servicing to qualified personnel. Do not attempt to open the amplifier casing unless specifically instructed for maintenance tasks like fuse or tube replacement.
• Voltage Selection: The amplifier has an internal voltage change-over switch (AC 110V to 240V). Ensure it is set correctly for your region's power supply before connecting to power. Incorrect voltage can cause severe damage.

3. Setup

3.1 Unpacking and Placement

Carefully remove the amplifier from its packaging. Place the unit on a stable, level surface with sufficient space for ventilation. Avoid direct sunlight, heat sources, and areas with high humidity.

3.2 Tube Installation

The Willsenton R-800i uses the following vacuum tubes:

• 1 x 12AX7 (pre-stage)
• 2 x 6SN7 (pre-stage)
• 2 x 300B (driver stage)
• 2 x 845 (power amplification, Class A single-ended)
• 1 x 274B (rectification)

Install the tubes into their corresponding sockets. The amplifier features an easy-to-install plug-in vacuum tube shield for protection. Ensure each tube is firmly seated in its socket. Refer to the markings on the chassis for correct placement.

3.3 Audio Connections

Connect your audio sources to the appropriate input terminals on the rear panel. The R-800i offers five groups of signal inputs: A, B, C (RCA), D (Balanced XLR), and E (PRE-IN).

• RCA Inputs (A, B, C): For standard unbalanced audio sources.
• Balanced XLR Input (D): For balanced audio sources, offering improved noise rejection.
• PRE-IN (E): This input allows the R-800i to function as a pure power amplifier, bypassing its pre-amplifier stage.

Connect your speakers to the speaker output terminals. The amplifier provides output terminals for 4 ohms, 8 ohms, and 16 ohms. Ensure your speakers are connected to the impedance matching terminals for optimal performance and to prevent damage to the amplifier.

3.4 Power Connection

Connect the power cord to the AC INPUT on the rear panel and then to a suitable wall outlet. The amplifier supports AC 110V to 240V, 60Hz/50Hz. Verify the internal voltage switch is set correctly for your region.

4. Operating Instructions

4.1 Power On/Off

Rotate the POWER switch on the front panel clockwise to the 'ON' position. The power indicator light will illuminate. The amplifier features a power-on high-voltage delay and mute delay function (approximately 30 seconds) to protect the tubes and circuitry during startup. During this delay, no sound will be produced.

4.2 Input Selection

Use the 'SELECTOR' knob on the front panel to choose your desired audio input (A, B, C, D, or E). The selected input will be indicated by a light.

4.3 Volume Control

Adjust the 'VOLUME' knob to control the output level. The R-800i uses a Japanese ALPS high-end potentiometer for precise volume adjustment.

4.4 Meter Functions

The front panel features dual meters. These meters can display either the output level (VU Meter) or the bias current for the power tubes (Bias Current Meter). Use the 'BIAS CURRENT / VU METER' switch to toggle between these modes. The 'LIGHT' switch controls the backlight for the meters.

4.5 Bias Adjustment

The R-800i includes a peripheral power tube bias current adjustment function. To adjust the bias, switch the meters to 'BIAS CURRENT' mode and use the 'BIAS ADJ.' knob for the respective tube (V1 or V2) to set the current according to the recommended specifications (refer to the amplifier's technical documentation or contact support if unsure). Proper bias adjustment is crucial for optimal sound and tube longevity.

4.6 Remote Control

The amplifier comes with an infrared remote control for convenient adjustment of volume and mute functions. Point the remote towards the remote control receiver window on the front panel.

5. Maintenance

5.1 Cleaning

Dust the amplifier regularly with a soft, dry cloth. Do not use liquid cleaners or abrasive materials, as they may damage the finish or components.

5.2 Tube Replacement

Vacuum tubes have a finite lifespan and will eventually need replacement. When replacing tubes, ensure the amplifier is powered off and unplugged. Allow tubes to cool completely before handling. Replace tubes with identical types and ensure they are correctly seated. It is recommended to replace tubes in matched pairs for optimal performance.

5.3 Fuse Replacement

The amplifier is equipped with a high-voltage fuse (T5AL250V) located near the power input on the rear panel. If the amplifier fails to power on, check this fuse. Always replace a blown fuse with one of the exact same type and rating to prevent damage or fire hazard.

6. Troubleshooting

• No Power: Check the power cord connection, the wall outlet, and the main fuse on the rear panel. Ensure the power switch is in the 'ON' position.
• No Sound: Verify that the correct input is selected, the volume is turned up, and speakers are properly connected. Check all tube installations. Allow for the 30-second power-on delay.
• Distorted Sound or Hum: Check all cable connections for secure fit. Ensure tubes are correctly seated. Adjust the 'HUM BALANCER' if necessary. Incorrect bias current can also cause distortion; check and adjust bias if needed.
• One Channel Silent: Check speaker connections for that channel. Verify tube integrity for that channel.
• Tubes Not Glowing: Some tubes may not glow visibly, but power tubes (like 300B and 845) should show a visible glow. If a power tube is not glowing, it may be faulty or improperly seated.

If problems persist after checking these points, please contact Willsenton customer support or a qualified service technician.

7. Specifications

8. Product Overview Video

Watch this official product video for a visual guide to the Willsenton R-800i amplifier's features and components.

9. Warranty and Support

For warranty information, technical support, or service inquiries, please refer to the documentation provided with your purchase or contact your authorized Willsenton dealer or the seller directly. Keep your purchase receipt as proof of purchase.