1. Introduction
This manual provides essential information for the proper setup, operation, and maintenance of your Bose RA-8 Stereo Receiver. Please read it thoroughly before using the unit to ensure optimal performance and safety. The Bose RA-8 is a compact stereo receiver featuring FM/AM tuner capabilities and an integrated amplifier, designed to deliver high-quality audio performance.
Figure 1: Front view of the Bose RA-8 Stereo Receiver. This image shows the compact design and primary controls of the unit.
2. Safety Information
Always observe the following safety precautions to prevent electric shock, fire, or damage to the unit:
- Power Source: Connect the unit only to an AC 100V, 50/60Hz power supply.
- Ventilation: Ensure adequate ventilation. Do not block ventilation openings.
- Water and Moisture: Do not expose the unit to rain or moisture. Do not place objects filled with liquids, such as vases, on the unit.
- Foreign Objects: Do not insert any metallic objects or flammable materials into the unit.
- Servicing: Do not attempt to service the unit yourself. Refer all servicing to qualified service personnel.
- Placement: Place the unit on a stable, level surface away from direct sunlight, heat sources, and excessive dust or vibrations.
3. Setup
3.1 Unpacking
Carefully remove the unit from its packaging. Retain the packaging materials for future transport or storage.
3.2 Connections
Ensure the unit is powered off before making any connections.
- Speaker Connection: Connect your speakers to the speaker terminals on the rear panel. The unit supports a load impedance of 6Ω to 16Ω. Ensure correct polarity (+ to + and - to -).
- Audio Source Connection: Connect external audio devices (CD player, MD player, tape deck, or other AUX sources) to the corresponding input jacks on the rear panel using appropriate audio cables. The input sensitivity for CD, MD, and TAPE/AUX is 200mV/47kΩ.
- Antenna Connection:
- FM Antenna: Connect the supplied FM antenna or an external FM antenna to the FM antenna terminal. For optimal reception, extend the antenna fully.
- AM Antenna: Connect the supplied AM loop antenna to the AM antenna terminals. Position the loop antenna for best reception.
- Power Connection: After all other connections are made, plug the power cord into an AC 100V wall outlet.
4. Operating Instructions
4.1 Power On/Off
Press the POWER button on the front panel or the remote control to turn the unit on or off.
4.2 Source Selection
Press the CD, MD, or TAPE/AUX buttons on the front panel or remote control to select the desired audio input source.
4.3 Tuner Operation
- Band Selection: Press the FM/AM button to switch between FM and AM bands.
- Manual Tuning: Use the TUNE +/- buttons to manually adjust the frequency.
- Auto Tuning (Scan Tuning): Press and hold the TUNE +/- buttons to automatically scan for the next available station.
- Preset Stations: The unit allows registration of up to 30 FM/AM broadcast stations. Refer to the detailed instructions for saving and recalling preset stations. The Area Fine Memory feature allows recalling stations by specifying a region.
- AM Stereo Reception: The unit supports AM stereo broadcasts.
4.4 Volume Control
Adjust the listening volume using the VOLUME knob on the front panel or the VOL +/- buttons on the remote control.
4.5 Timer Functions
- AI Sleep Timer: This function allows the unit to automatically turn off after a set period, useful for listening to music while falling asleep.
- Advanced Timer: The unit features an advanced timer for scheduled recording or as an alarm function. Consult the full manual for detailed programming instructions.
5. Maintenance
To maintain the performance and appearance of your Bose RA-8, follow these guidelines:
- Cleaning: Wipe the unit with a soft, dry cloth. For stubborn stains, use a cloth lightly dampened with water or a mild detergent, then wipe dry. Do not use abrasive cleaners, alcohol, benzene, or thinners, as these can damage the finish.
- Ventilation: Periodically check that the ventilation openings are free from dust and obstructions.
- Power Cord: Inspect the power cord regularly for any damage. If damaged, discontinue use and contact qualified service personnel.
6. Troubleshooting
If you experience problems with your Bose RA-8, refer to the following common issues and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Power cord not connected; Power outlet faulty | Ensure power cord is securely plugged in; Try a different outlet. |
| No sound | Volume too low; Incorrect input source selected; Speaker cables disconnected | Increase volume; Select correct input source; Check speaker connections. |
| Poor FM/AM reception | Antenna not connected or poorly positioned; Interference | Connect and adjust antenna position; Move unit away from other electronic devices. |
| Remote control not working | Batteries depleted; Obstruction between remote and unit | Replace remote control batteries; Remove any obstructions. |
If the problem persists after trying these solutions, please contact Bose customer support or a qualified service technician.
7. Specifications
| Feature | Specification |
|---|---|
| FM Tuner Section | |
| Frequency Range (STEP) | 76 - 108 MHz (100 kHz step) |
| Practical Sensitivity | 14.2 dBf (MONO) |
| S/N Ratio (65 dBf) | Monaural: 75 dB or more |
| Frequency Characteristics (Stereo) | 30 - 15,000 Hz (+1 dB, -3 dB) |
| Distortion (IHF, 65 dBf, Monaural 1 kHz) | 0.4% or less |
| Stereo Separation (1 kHz) | 40 dB or more |
| AM Tuner Section | |
| Frequency Range (STEP) | 531 - 1,629 kHz (9 kHz step) |
| Practical Sensitivity (Loop Antenna) | 57 dBμV/m |
| Total Harmonic Distortion | 0.9% or less |
| S/N Ratio (80 dB/m) | 40 dB or more |
| Stereo Separation (400 Hz) | 20 dB or more |
| Amplifier Section | |
| Practical Maximum Output (1 kHz, EIAJ) | 25 W + 25 W (6Ω) |
| Total Harmonic Distortion | 0.03% or less |
| Load Impedance | 6Ω - 16Ω |
| Input Sensitivity/Impedance (1 kHz) | CD: 200 mV/47 kΩ MD: 200 mV/47 kΩ TAPE/AUX: 200 mV/47 kΩ |
| Maximum Allowable Input (1 kHz) | CD, MD: 3 V (THD 1.0%) |
| Output Voltage (1 kHz) | MD/TAPE/AUX: 200 mV/47 kΩ |
| Output Impedance (1 kHz) | MD/TAPE/AUX: 2.2 kΩ |
| Frequency Characteristics (1 W) | CD, MD, TAPE/AUX: 10 - 70,000 Hz (+3 dB, -3 dB) |
| S/N Ratio | CD, MD, TAPE/AUX: 80 dB or more |
| General | |
| Power Supply Voltage | AC 100 V |
| Power Supply Frequency | 50/60 Hz |
| Power Consumption | 40 W |
| Power Outlet (Non-interlocked, Max) | 100 W |
| External Dimensions (W x H x D) | 200 x 72.5 x 280 mm |
| Weight (Main Unit Only) | 3.1 kg |
| Connectivity Technology | AUX |
| Control Method | Remote |
8. Warranty and Support
Bose products are designed for reliability and performance. For warranty information, please refer to the warranty card included with your product or visit the official Bose website. For technical support, troubleshooting assistance beyond this manual, or service inquiries, please contact Bose customer support through their official channels. Keep your purchase receipt as proof of purchase for warranty claims.
For more information, you may visit the Bose Store on Amazon.co.jp.
