Bose RA-12 American Sound System Stereo Receiver

1. Product Overview

The Bose RA-12 American Sound System Stereo Receiver is a compact audio component designed to deliver high-quality sound reproduction. It integrates FM/AM radio capabilities with amplifier functions, offering versatile audio playback options for your home.

Figure 1: Front view of the Bose RA-12 Stereo Receiver, showing the display, control buttons, volume knob, USB port, and headphone jack.

2. Key Features

• FM/AM Radio with Advanced Memory: Features an Area Fine Memory function that recalls receivable broadcasts in your specified region, displaying station names. It allows storage of up to 30 FM/AM stations and includes scan tuning for automatic frequency adjustment.
• Bose Patented P.A.P. Circuit: Ensures optimal acoustic balance at any volume level, providing a consistent and high-quality listening experience.
• Room Acoustic Compensator (R.A.C.): Equipped with BASS and TREBLE adjustments, this feature corrects only the frequency bands that are most susceptible to the listening room's structure, optimizing sound for your environment.
• Convenient Timer Functions: Includes a one-touch ON/OFF timer via remote control, similar to an alarm clock, for scheduled playback. A sleep timer function automatically switches the unit to standby mode after a user-defined period (10 to 90 minutes in 10-minute increments).

3. Setup Guide

3.1 Unpacking

Carefully remove the Bose RA-12 from its packaging. Retain all packaging materials for future transport or service.

3.2 Placement

Place the unit on a stable, flat surface with adequate ventilation. Avoid placing it near heat sources, direct sunlight, or in areas with high humidity or dust.

3.3 Connections

1. Power Connection: Connect the power cord to the AC100V outlet. Ensure the power switch on the rear panel is in the OFF position before connecting.
2. FM Antenna: Connect the supplied FM antenna to the FM ANT terminal on the rear panel for optimal FM reception.
3. AM Antenna: Use the supplied loop antenna for AM reception. Position it away from the main unit and other electronic devices to minimize interference.
4. Audio Input (AUX IN): Connect external audio devices (e.g., CD player, MD player, auxiliary devices) to the AUX IN jacks on the rear panel using appropriate audio cables.
5. Speaker Connection: Connect your speakers to the speaker terminals on the rear panel. Ensure correct polarity (+ to + and - to -) for each speaker. The unit supports speakers with a load impedance of 6Ω to 16Ω.

Figure 2: This video demonstrates the various input and output options available on a similar CD stereo mini-component, including connections for USB, AUX, and CD playback.

4. Operating Instructions

4.1 Power On/Off

To power on the unit, flip the main power switch on the rear panel to ON, then press the power button on the front panel or remote control. Press the power button again to put the unit into standby mode.

4.2 Source Selection

Use the input selector buttons on the front panel or remote control to choose between FM, AM, CD, MD, or AUX inputs.

4.3 FM/AM Radio Operation

1. Select FM or AM mode.
2. Use the tuning buttons to manually adjust the frequency or activate scan tuning to automatically find stations.
3. To use Area Fine Memory, select the desired region. The unit will display receivable stations with their names.
4. To store a station, tune to the desired frequency, then press and hold a preset button until the display confirms storage. Up to 30 stations can be stored.

4.4 Volume and Sound Adjustment

Adjust the master volume using the large rotary knob on the front panel or the volume buttons on the remote control. Use the BASS and TREBLE controls (part of the R.A.C. system) to fine-tune the sound to your preference and room acoustics.

4.5 Timer Functions

• ON/OFF Timer: Set a specific time for the unit to turn on or off. Refer to the detailed instructions in the full manual for setting specific times.
• Sleep Timer: Press the sleep timer button on the remote control repeatedly to cycle through available sleep times (10, 20, 30, ..., 90 minutes). The unit will automatically enter standby mode after the selected duration.

5. Maintenance

5.1 Cleaning

Wipe the exterior of the unit with a soft, dry cloth. Do not use abrasive cleaners, waxes, or solvents. For stubborn stains, lightly dampen the cloth with water and a mild detergent, then wipe dry.

5.2 Ventilation

Ensure that the ventilation openings on the unit are not blocked. Proper airflow is essential to prevent overheating.

5.3 Fuse Replacement

If the unit does not power on, check the fuse. Fuse replacement should only be performed by qualified service personnel. Refer to the specifications for the correct fuse type.

6. Troubleshooting

7. Specifications

7.1 FM Section

• Frequency Range (STEP): 76.0~90.0MHz (100kHz step)
• Usable Sensitivity: 10dBf (MONO)
• S/N Ratio: 70dB or more (65dBf)
• Frequency Response (Stereo): 30~15,000Hz (-1dB)
• Distortion (Monaural): 0.4% or less (1kHz, 65dBf)
• Stereo Separation: 40dB or more (1kHz)

7.2 AM Section

• Frequency Range (STEP): 522~1,629kHz (9kHz step)
• Usable Sensitivity (Loop Antenna): 45dBμV/m
• Total Harmonic Distortion: 0.7% or less
• S/N Ratio: 40dB or more (999kHz, 50mV input)

7.3 Amplifier Section

• Practical Maximum Output: 35W + 35W (1kHz, 0.1%, 6Ω)
• Total Harmonic Distortion: 0.03% or less (6Ω, 10W)
• Load Impedance: 6Ω~16Ω
• Input Sensitivity/Input Impedance (1kHz):
  • CD, MD, AUX: 200mV/47kΩ
  • PHONO: 2.5mV/47kΩ
• Maximum Allowable Input (1kHz):
  • CD, MD, AUX: 2.0V
• Frequency Response (CD, MD, AUX): 20~90,000Hz (±0.5dB, 1W)
• S/N Ratio:
  • AUX: 90dB or more (IHF-A)
  • PHONO: 75dB or more
• Channel Separation: 65dB

7.4 General

• Power Voltage: AC100V
• Power Frequency: 50/60Hz
• Power Consumption: 75W (IEC 60065)
• Energy Saving Mode: Approx. 1W
• Power Outlet (Non-Interlocked, Max): 100W
• External Dimensions (W×H×D): 230mm × 82mm × 273mm
• Standard Mass (Weight): 3.7kg (main unit only)

8. Warranty and Support

For warranty information and technical support, please refer to the documentation included with your purchase or visit the official Bose website. Keep your proof of purchase for warranty claims.