Sony MDR-RF855RK Wireless Stereo Headphone System
Model: MDR-RF855RK
Introduction
Thank you for purchasing the Sony MDR-RF855RK Wireless Stereo Headphone System. Please read this manual carefully before operating the device and keep it for future reference.
Package Contents
- Transmitter TMR-RF855R (1)
- Headphones MDR-RF855R (1)
- AC Power Adapter (1)
- Rechargeable Nickel-Metal Hydride Battery (BP-HP550-11) (1)
- Connecting Cable (Stereo mini plug to pin plug x 2), 1 m (1)
- User Manual (this manual) (1)
- Warranty Card (1)
Key Features
- Wireless headphone system with long battery life and approximately 100 m (330 ft) operating range.
- Easy charging by placing the headphones on the transmitter.
- 40 mm diameter drivers for deep bass reproduction.
- Auto on/off function for extended battery life.
- Up to 18 hours playback on a rechargeable battery or 28 hours on alkaline batteries.
Safety Precautions
⚠️ WARNING: To reduce the risk of fire or electric shock, do not expose the unit to dripping or splashing. Do not place liquid-filled objects, such as vases, on the unit.
Do not open the casing. Refer servicing to qualified personnel only.
Ensure the AC power adapter is plugged into an easily accessible outlet. Disconnect it immediately if the unit malfunctions.
Do not install the unit in a confined space, such as a bookshelf or built-in furniture.
Do not expose batteries (installed or supplied) to excessive heat, such as prolonged exposure to sunlight or fire.
Excessive sound pressure from headphones or earphones may cause hearing loss.
The CE marking is valid only in countries where it is legally enforced, primarily within the European Economic Area (EEA).
Disposal of Old Electrical and Electronic Equipment: This symbol [recycling symbol] on the product or packaging indicates it should not be treated as household waste. It must be taken to an appropriate collection point for recycling. Proper disposal prevents negative environmental and health impacts.
Disposal of Used Batteries: This symbol [battery disposal symbol] on the battery or packaging indicates it should not be disposed of with household waste. Take used batteries to designated collection points.
Getting Started & Setup
Connecting the Transmitter
Connect your audio source to the transmitter using the provided connecting cable. The transmitter can connect via the headphone jack or audio output jacks (L/R) of your audio/video component.
Diagram Description: Shows connecting a stereo mini plug to the headphone jack of a TV or music player, and connecting RCA plugs to the audio output jacks of a stereo system or Blu-ray/DVD player.
Inserting the Battery
Insert the rechargeable battery (BP-HP550-11) into the left headphone earcup, observing correct polarity. The battery has contacts that align with contacts on the transmitter for charging.
Diagram Description: Shows the rechargeable battery being inserted into the headphone, aligning contacts [contact alignment diagram].
Using the Headphones
Auto On/Off Function
The headphones automatically turn on when worn and turn off when removed. Wear the headphones vertically for proper function. Do not pull the self-adjusting band when not in use to save battery [battery saving tip].
RF Signal Transmission
The transmitter automatically broadcasts RF signals once an audio signal is detected from the connected component. Ensure the transmitter is placed for optimal reception, avoiding metal surfaces which can cause noise or reduce range.
Auto Power Off (Low Signal)
If the signal is weak or absent for approximately 5 minutes, the transmitter will automatically turn off. The POWER/GREEN indicator [green indicator] on the transmitter will blink green for 5 minutes before shutting down. To restart, ensure there is an audio signal and increase the volume of the connected audio component if necessary, while reducing headphone volume.
Charging the Battery
Initial Charge
The supplied rechargeable battery is not charged from the factory. Charge it fully before first use.
Automatic Charging
Place the headphones onto the transmitter. They will automatically turn off, and charging will begin. The CHG/RED indicator [red indicator] will light up red. Charging is complete when the indicator turns off.
Diagram Description: Shows headphones placed on the transmitter for charging.
Charging Time and Battery Life
Full charging takes approximately 7 hours. The rechargeable battery provides up to 18 hours of playback. Alkaline AAA batteries (sold separately) provide up to 28 hours.
Indicator Status: CHG/RED lights red [?] during charging. POWER indicator shows battery status (green [?] for sufficient charge, off/dim/blinking for low charge).
Checking Battery Level
Pull the self-adjusting band and check the POWER indicator. Green [?] means sufficient charge.
Troubleshooting Charging Issues
Ensure headphones are correctly positioned on the transmitter for contact. Clean contacts if dirty. If the CHG/RED indicator does not light up [? not lit], the battery may have reached the end of its service life.
Using with Dry Cell Batteries
Two AAA alkaline batteries (sold separately) can be used. Insert them as shown in the setup step. The charging function is disabled when dry cell batteries are installed.
Connection and Volume Tips
Do not connect to AUDIO IN 1 and AUDIO IN 2 simultaneously. If connecting to a headphone jack, ensure the audio component's volume is set high enough without distortion. Avoid increasing volume during quiet scenes in videos to prevent hearing damage during loud scenes.
Improving Reception
The system uses 800 MHz RF signals. Range can be affected by building materials (steel reinforcement), metal furniture, other electronic devices, and proximity to roads or wireless communication systems.
The optimal range is approximately 100 meters (330 ft). If experiencing noise, reduce the distance or change the transmitter channel using the CHANNEL switch and tune the headphones using the TUNING switch.
Be aware of "dead zones" [dead zone indicator] where RF signals cannot be received; slight repositioning of the transmitter can help.
Replacing Ear Pads
Ear pads can be replaced if dirty or worn. They are not sold separately and must be ordered from a Sony dealer. To replace:
- Gently pull the old ear pad from the groove on the earcup.
- Align the new ear pad with the groove and press it into place, rotating it around the earcup until secure.
Diagram Description: Shows how to remove old ear pads and fit new ones.
Troubleshooting
No Sound / Low Volume
Check connections, ensure audio source is on, adjust volume on both source and headphones. Try changing channels.
Distorted or Intermittent Sound (Noise)
Move headphones closer to transmitter or reposition transmitter. Avoid metal surfaces. Adjust source volume. Change channels. Ensure battery is charged/replaced.
Loud Background Noise
Adjust source volume. Ensure battery is charged/replaced. Avoid metal surfaces. Use headphones closer to the transmitter.
POWER/GREEN Indicator Blinking Green [? blinking]
No or weak signal. Start playback or increase source volume. Transmitter will auto-off after 5 minutes of no signal.
Sound Cuts Out
Transmitter auto-off due to no/weak signal. Increase source volume.
Battery Not Charging / CHG/RED Indicator Issues [? not lit]
Ensure correct headphone placement and contact. Use only the supplied BP-HP550-11 battery. Clean contacts. If indicator remains off, battery may have reached the end of its service life.
Specifications
Radio Frequency Stereo Transmitter (TMR-RF855R)
- Modulation: FM Stereo
- Carrier Frequencies: 863.52 MHz, 864.02 MHz, 864.52 MHz
- Channels: K1, K2, K3
- Transmission Distance: Approx. 100 m (max.)
- Audio Inputs: Pin jacks (L/R), Stereo mini jack
- Power Requirements: DC 12 V (from supplied AC adapter)
- Dimensions: Approx. 180 mm × 94 mm × 126 mm (W/H/D)
- Mass: Approx. 310 g
- Power Consumption: 3.0 W
- Operating Temperature: 5°C to 35°C
Wireless Stereo Headphones (MDR-RF855R)
- Frequency Response: 10 – 22000 Hz
- Power Source: Supplied BP-HP550-11 Ni-MH battery or commercially available AAA dry cell batteries
- Mass: Approx. 280 g (with battery)
- Operating Temperature: 5°C to 35°C
Important Notes
If the system will not be used for an extended period, disconnect the AC adapter and remove the battery to prevent damage from leakage.
Do not expose the unit to direct sunlight, high temperatures, or humidity.
Disconnecting the AC adapter before turning off the headphones may cause noise.
Avoid exposing the unit to extreme temperatures, direct sunlight, moisture, sand, dust, or mechanical shock.
Listening Safely
Do not set the volume too high to prevent hearing damage. If you experience ringing in your ears, reduce the volume or stop listening.
Listen at a moderate volume to be aware of your surroundings and not disturb others.
Service
For questions or issues not covered in this manual, contact your nearest Sony dealer. For repairs, take both the headphones and transmitter to a Sony dealer.
