Juson Audio FTA88-N 180W KT88 Valve Tube Amplifier User Manual

1. Introduction

The Juson Audio FTA88-N is a high-fidelity 180W KT88 valve tube amplifier designed to deliver a rich and dynamic audio experience. It features both MOSFET and Single-Ended tube amplification modes, offering versatility in sound characteristics. The amplifier supports a wide range of input sources, including Phono, Coaxial, Optical, CD, DVD, and Bluetooth 5.4 with advanced codecs like aptX-HD and LDAC. This manual provides essential information for safe operation, setup, and maintenance of your amplifier.

2. Safety Instructions

• Power Supply: Ensure the amplifier is connected to a power outlet with the correct voltage (AC 115V or AC 230V) as indicated on the rear panel. Use the provided power cord.
• Ventilation: Do not block ventilation openings. Ensure adequate airflow around the unit to prevent overheating.
• Moisture: Keep the amplifier away from water, moisture, and high humidity environments.
• Heat Sources: Avoid placing the amplifier near radiators, heat registers, stoves, or other heat-producing appliances.
• Tube Handling: Vacuum tubes can become very hot during operation. Avoid touching them directly. Allow sufficient time for tubes to cool before handling or replacing.
• Cleaning: Disconnect the power cord before cleaning. Use a soft, dry cloth. Do not use liquid cleaners or aerosol cleaners.
• Servicing: Do not attempt to service this product yourself. Refer all servicing to qualified service personnel.
• Volume Levels: Prolonged exposure to high volume levels can cause permanent hearing damage. Adjust volume to a comfortable level.

3. Product Overview

3.1 Front Panel

The front panel provides controls for input selection, volume, and visual feedback from the VU meters.

• Input Source Selector: Rotary knob to select between various audio inputs (BT, OPT, COAX, PHONO, AUX, PC-USB).
• Input Sources Indicator: LEDs indicating the currently selected input source.
• VU Meters: Visual indicators displaying the audio output level for each channel.
• IR Receiver: Receives signals from the remote control.
• Power Switch: Turns the amplifier on or off.
• Volume Control: Rotary knob to adjust the overall output volume.

3.2 Rear Panel

The rear panel houses all input and output connections, along with the voltage selector and cooling fan switch.

• PC-USB Input (Type-B): Connects to a computer for digital audio playback.
• Active Subwoofer Output (SW OUT): Connects to an active subwoofer.
• Bluetooth Antenna: For wireless Bluetooth connectivity.
• Ground Terminal (GND): For grounding turntables to reduce hum.
• Cooling Fan ON/OFF Switch: Activates or deactivates the internal cooling fan.
• AC Voltage Selector Switch: Selects between 115V and 230V AC power input.
• Digital Optical Input (OPT): For optical digital audio sources.
• Digital Coaxial Input (COAX): For coaxial digital audio sources.
• AUX RCA Input: For analog audio sources via RCA cables.
• PHONO RCA Input: For turntables with Phono output.
• Passive Speakers Output (FL+/FL-, FR+/FR-): Connects to passive speakers.
• AC Power Input: Connects the amplifier to the main power supply.

4. Setup

Follow these steps to set up your Juson Audio FTA88-N amplifier:

1. Unpacking: Carefully remove the amplifier and all accessories from the packaging. The included components are the FTA88 amplifier, user manual, power cord, and remote control.
2. Placement: Place the amplifier on a stable, flat surface with adequate ventilation. Ensure there is enough space around the unit for heat dissipation.
3. Voltage Selection: Before connecting the power cord, verify that the AC Voltage Selector Switch on the rear panel is set to the correct voltage for your region (115V or 230V).
4. Speaker Connection: Connect your passive speakers to the Passive Speakers Output terminals (FL+/FL-, FR+/FR-) on the rear panel. Ensure correct polarity (+ to + and - to -).
5. Input Source Connection:
   • Bluetooth Antenna: Screw the provided Bluetooth antenna into its designated port on the rear panel.
   • Digital Inputs (Optical/Coaxial): Connect your digital audio sources (e.g., CD player, TV) to the OPT or COAX inputs using appropriate cables.
   • Analog Input (AUX): Connect analog audio sources (e.g., CD player, DVD player) to the AUX RCA inputs.
   • Phono Input: For turntables, connect to the PHONO RCA inputs. If your turntable has a ground wire, connect it to the GND terminal on the amplifier.
   • PC-USB Input: Connect your computer to the PC-USB (Type-B) input using a USB Type-B to Type-A cable.
   • Subwoofer Output: If using an active subwoofer, connect it to the SW OUT port.
6. Power Connection: Once all audio connections are made, connect the power cord to the AC Power Input on the rear panel and then to a wall outlet.

4.1 Connecting to a Turntable

The FTA88-N amplifier features a dedicated PHONO input with a built-in preamplifier, allowing direct connection of turntables. There are two main types of turntables:

• Modern Turntables with Built-in Preamp: These turntables usually have a switch for "PHONO" or "LINE" output.
  1. Set the turntable's output to "PHONO" signal output.
  2. Remove any protective caps from the amplifier's PHONO input.
  3. Connect the turntable's RCA cables to the amplifier's PHONO input.
  4. Connect the turntable's ground wire to the amplifier's GND terminal.
• Vintage Turntables (no built-in preamp): These turntables typically only have a Phono output.
  1. Remove any protective caps from the amplifier's PHONO input.
  2. Connect the turntable's RCA cables to the amplifier's PHONO input.
  3. Connect the turntable's ground wire to the amplifier's GND terminal.

4.2 Connecting USB Devices

The amplifier supports connecting to USB devices via its Type-B port for digital audio playback from a computer or other compatible devices.

1. Connect a USB Type-B to Type-A cable to the PC-USB input on the amplifier's rear panel.
2. Connect the Type-A end of the cable to your computer.
3. For mobile devices (phones, tablets), you may need an OTG (On-The-Go) adapter to convert the USB Type-A connection to your device's port (e.g., USB-C, Lightning).
4. Ensure the USB drive capacity is less than 128GB if connecting directly to the front USB port (if available, not explicitly shown on rear panel image but mentioned in video).

5. Operating Instructions

This section details how to operate your Juson Audio FTA88-N amplifier.

5.1 Power On/Off

Press the Power Switch on the front panel to turn the amplifier on or off. Allow a brief warm-up period for the tubes after powering on.

5.2 Input Selection

Rotate the Input Source Selector knob on the front panel to choose your desired audio source (BT, OPT, COAX, PHONO, AUX, PC-USB). The corresponding LED indicator will illuminate.

5.3 Volume Control

Adjust the Volume Control knob on the front panel to set the desired listening level. The VU meters will visually indicate the output level.

5.4 Bluetooth Operation

1. Select "BT" as the input source using the Input Source Selector.
2. On your Bluetooth-enabled device (smartphone, tablet), search for available Bluetooth devices and select "Juson Audio FTA88-N".
3. Once paired, you can stream audio wirelessly.
4. Note: If the speaker volume is low during Bluetooth input, check your device's Bluetooth settings to ensure the audio output volume is not restricted by the phone speaker's volume.

5.5 Dual Operating Modes (MOSFET / Single-Ended)

The FTA88-N offers two distinct amplification modes:

• MOSFET Mode: Provides a smooth, highly stable, and distortion-free sound output. This mode is generally more powerful.
• Single-Ended Tube Mode: Delivers a warm, vintage sound characteristic, often preferred for vocal-centric music.

Refer to the amplifier's specific controls or internal switches (if applicable, consult the detailed product diagram or internal instructions) for switching between these modes. Ensure the amplifier is powered off before making any internal mode changes.

6. Maintenance

• Cleaning: Regularly wipe the amplifier's exterior with a soft, dry cloth. Avoid abrasive cleaners or solvents.
• Tube Replacement: Vacuum tubes have a finite lifespan. If you notice a degradation in sound quality or tube failure, consult qualified personnel for replacement. Preamp tubes (6H1N/6N1/6N2/ECC85) can be replaced by ECC83/12AX7 for sound customization. Ensure the amplifier is powered off and cooled before attempting any tube changes.
• Cooling Fan: In TF (Single-Ended) mode, if the working temperature is high, you may need to manually turn on the built-in cooling fan using the switch on the rear panel.

7. Troubleshooting

8. Specifications

• Model: FTA88-N
• Brand: Juson Audio
• Output Power: 180 Watts (Total)
• Number of Channels: 2
• Tube Type: KT88 power-amp tubes, 6H1N/6N1/6N2/ECC85 preamp tubes (upgradeable to ECC83/12AX7)
• Operating Modes: MOSFET, Single-Ended Tube
• Inputs: PHONO (RCA), COAX (Digital), OPT (Digital), AUX (RCA), PC-USB (Type-B), Bluetooth 5.4 (aptX-HD, LDAC)
• Outputs: Passive Speaker Terminals, Active Subwoofer Output (SW OUT)
• Dimensions (L x W x H): 14.57 x 14.96 x 8.11 inches
• Weight: 14.8 Kilograms
• Included Components: FTA88 amplifier, user manual, power cord, remote control.

9. Warranty and Support

The Juson Audio FTA88-N amplifier comes with the following warranty:

• Electron Tubes: 1 Year Warranty
• Whole Unit: 2 Years Warranty
• Technical Support: Life-time technical support is provided.

For warranty claims or technical assistance, please contact Juson Audio customer support.