TLDR;

I just unpaired the devices, then started a YouTube video on my Ubuntu machine and then repeated the steps below (pairing) while the audio was playing. At that point I’ve been able to send audio to my Echo Plus.

Yesterday, I tried to use my Amazon Echo Plus as bluetooth speaker on my media center Running Ubuntu 20.04.

I paired the Echo Plus using Alexa app on my phone following these steps:

  1. Open Alexa app on your phone and go to devices tab, then Echo & Alexa.
  2. Choose your Echo Plus from list and then the gear icon on top left.
  3. Under Wireless tab, choose Bluetooth Devices and then Pair new device.` Now the Echo Plus is in Pairing Mode.
  4. On Ubuntu, discover devices with Bluetooth and then pair Echo-s5u.

Following these steps, paired was successful but I couldn’t send any audio to Echo Plus.

Why? Because the Echo was recognized as microphone instead of a speaker.

The only workaround I found at the moment to avoid this, is to pair the Echo Plus while you’re playing some audio on your Ubuntu machine.

When you pair an Echo Plus to a device, the device and the Echo Plus need to establish a connection using the A2DP (Advanced Audio Distribution Profile) protocol. This protocol is used to transmit high-quality audio over Bluetooth.

When you play audio on the machine before pairing the Echo Plus, it initiates the A2DP connection between the two devices. This allows the Echo Plus to establish a connection with the machine as an audio sink, which enables it to receive and play audio.

It’s possible that the Echo Plus is not able to initiate the A2DP connection on its own, so playing audio on the machine before pairing helps establish the connection. Once the connection is established, the Echo Plus should be able to play audio.

I just unpaired the devices, then started a YouTube video on my Ubuntu machine and then repeated the steps above. A that point I’ve been able to send audio to my Echo Plus.