Avantree BTTC-218 Bluetooth Adapter Relay User Manual

: June 14, 2024
: Avantree

Table of Contents

Avantree BTTC-218 Bluetooth Adapter Relay
Product Information
Product Usage Instructions
Box Contents
**Product Introduction
Button Functions
LED Indicators
Charging the Transmitter
Connecting to an Audio Source
Connecting to Your Headphones
Adding a Second Pair of Headphones
Reconnecting Your Headphones
Specifications
FAQ
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

Avantree BTTC-218 Bluetooth Adapter Relay

Product Information

Model No.: BTTC-218

Contents: Relay Transmitter, Dual 3.5mm Male to 3.5mm Female Adapter, USB C Charging Cable (1.5ft / 0.5m), Traveling Pouch
Product Overview: The Relay is a wireless audio transmitter that allows you to connect your Bluetooth headphones to an audio source, such as an in-flight entertainment system or any other device with an AUX 3.5mm audio connector.
Functions: The Relay has three buttons: ON/OFF, Volume adjustment, and Multifunctional button (MFB). The ON/OFF button is used to turn the Relay on or off. The Volume adjustment button is used to adjust the volume by pressing it once and holding it down. The Multifunctional button (MFB) has multiple functions, including initiating reconnection to the last paired device, showing the battery level when double-clicked, and entering pairing mode when held down for 2 seconds.
LED Indicators: The Relay has LED indicators that provide status information. The different LED indicator statuses include pairing mode, connection, reconnecting to the last-used device, standby, clearing pairing history, charging, and battery status.

Product Usage Instructions

Charging the Transmitter:

Double-click the MFB to check the battery level. It’s recommended to initiate charging when the Relay is at 25% battery level or below.
Plug the provided USB C charging cable into the charging port of the Relay transmitter.
Connect the other end of the USB C charging cable to a 5V/500mA-2A rated USB adapter or a PC USB port.
A flashing white light on the transmitter indicates that charging is in progress. The four lights will turn solid white and then off to indicate a full charge.

Connecting to an Audio Source:

Plug the Relay into an in-flight entertainment system or any other audio source with an AUX 3.5mm audio connector. Use the provided adapter if necessary.

Connecting to Your Headphones:

Slide the Relay’s ON/OFF switch to the ON position. For first-time use, the Relay will enter PAIRING mode automatically. For subsequent use, put your Relay into PAIRING mode by pressing and holding the MFB until the LED flashes blue and red alternately.
Put your Bluetooth headphones into PAIRING mode.
Keep the Relay and your device close together and wait for 5-10 seconds until they connect. Once connected, the indicator will turn solid blue.
Note: If your device and the transmitter fail to connect, ensure that your device is properly placed into PAIRING mode. Check your device’s online user manual for more details.

Box Contents

**Product Introduction

**

Product Overview

Button Functions

LED Indicators

No.	Indicator	Status

A

B

| Any of the 4 LED indicators flashing| Charging
All the 4 LED indicators off| Fully charged
Solid white for 1 second (after power on)| Battery status

Charging the Transmitter

Double-click the MFB to check the battery level. It’s best to initiate charging when the Relay is at 25% battery level or below.
Plug the provided USB C charging cable into the charging port, then connect the other end to a 5V/500mA-2A rated USB adapter (your phone charger or similar should work) or PC USB port.
A flashing white light on the transmitter indicates that charging is in progress; the four lights will turn solid white then off to indicate a full charge.

Connecting to an Audio Source

Plug the Relay into an in-flight entertainment system (use the adapter if necessary) or any other audio source with an AUX 3.5mm audio connector.

Connecting to Your Headphones

STEP 1
Slide the Relay’s ONs OFF ch to the “ON” position. For first-time use, the Relay will enter PAIRING mode automatically. For subsequent use, put your Relay into PAIRING mode by pressing & holding the MFB until the LED flashes blue and red alternately.
STEP 2
Put your Bluetooth headphones into PAIRING mode.
STEP 3
Keep the Relay & your device close together and wait for 5-10s until they connect. Once connected, the indicator will turn solid blue.

NOTE : Most cases where your device & the transmitter fail to connect happen because the device is not properly placed into PAIRING mode. Double- check that your device is successfully in PAIRING mode (typically indicated by an LED indicator’s alternate red & blue flashes). For more details, please refer to your device’s online user manual.

Adding a Second Pair of Headphones

You can connect and simultaneously listen through two pairs of headphones if desired.

STEP 1
Once your first device is successfully connected, put your Relay into PAIRING mode once again by pressing & holding the MFB until the LED flashes blue and red alternately.
STEP 2
Put your second pair of Bluetooth headphones into PAIRING mode. Please refer to your headphones’ user manual for more details if necessary.
STEP 3
Keep the Relay & your second device close together and wait for 5-10s until they connect.
Once connected, both indicators will turn solid blue.

NOTE : The dual headphones support function works with most headphones but not all. Certain true wireless earbuds in particular do not work well with Bluetooth transmitters’ dual headphones mode. If you’re not getting audio while dual-linked, try turning the affected headphones off and then on again. In some cases, dual pairing with Airpods may trigger their audio MUTE function. If this happens, put them back in their charging case (with the lid open) for 2 seconds, then take them out again to return them to normal. This may help to solve the problem.

Reconnecting Your Headphones

You typically do NOT need to re-pair your Bluetooth headphones with the Relay every time. Once successfully paired, they should automatically reconnect when both devices are turned on (this may take a few seconds).
If your device does not automatically reconnect after 5-10 seconds, you can manually initiate reconnection by pressing the Relay’s MFB once and waiting for 5-10 seconds. If this still doesn’t work, try initiating reconnection on your audio device as well (typically done by pressing the main Bluetooth PLAY button on your headphones once). If they still don’t connect, you may need to repair your device.

NOTE : If you paired your headphones with a different Bluetooth device, turn Bluetooth OFF on said device(s). Airpods in particular will always prioritize Apple devices for automatic pairing, so you’ll need to turn your iPhone’s Bluetooth OFF when pairing your Airpods with the Relay.

Specifications

Bluetooth version	v5.3
Supported profiles	A2DP; AVRCP
Audio codecs	aptX adaptive; aptX LowLatency, aptX, SBC

Input voltage

/ current

| DC5.0V / 500Ma-2A
Operating range| Up to 33ft / 10m
Product dimensions| 125mmx24mmx12mm
Net weight| 15g

FAQ

Below are some of the most common questions people have during setup.

My Relay’s at max volume; why is the sound still so quiet?
Try adjusting the volume on both the Relay, your headphones, and/or the audio source. You should be able to reach sufficient volume levels by adjusting all three.
Can I use this while it’s charging?
Yes, you can use it while it’s charging.
Does this work on a regular TV?
As long as your TV has an AUX or RCA audio output jack, the Relay will work with it. Please note that you’ll need an AUX 3.5mm to RCA adapter (not included) in order to transmit audio via your TV’s RCA ports.
Why am I getting audio delay?
Both the sender (i.e. the Relay) and the receiver (i.e. your Bluetooth headphones) must support either aptX Low Latency or aptX Adaptive in order to eliminate audio latency. You can check your device’s specs to ensure it supports either of these audio codecs. Please note that most true wireless earbuds do not currently support aptX Low Latency or aptX Adaptive audio codecs.
Why aren’t my headphones connecting?
Why aren’t I getting sound from my headphones?
For answers to questions like these and for a full FAQ list, you can visit avantree.com/support/relay, or you can contact us directly for additional assistance.