ST1 Audio Encoder / Decoder - Audio Distribution Examples

Mar 03, 2025

Overview

The Just Add Power Sound Encoder/Decoder - model ST1 - is capable of sending or receiving stereo audio from a Just Add Power system. As a Transceiver, you begin by choosing whether it will act as a Encoder or Decoder - an input or an output - and build the system accordingly.

Audio Capabilities

Stereo audio only
No down-mixing capability
192 kHz
24-bit
Volume adjustment in Decoder Mode

Encoder Mode Options

As a Encoder, the ST1 can:

Provide a stereo audio source to any Decoder in a Just Add Power system
Provide a stereo audio source to an audio-only system made up of multiple ST1s
Provide a stereo audio source that can be mixed with a video signal from another Just Add Power Encoder so that a Just Add Power Decoder is viewing video and audio from two different sources
Provide a pathway for Audio Return Channel - ARC - to get from the Smart TV back to the AVR

Decoder Mode Options

As a Decoder, the ST1 can:

Play stereo audio from any Encoder in a Just Add Power system (Encoder must be outputting stereo audio)
Play stereo audio from an audio-only system made up of multiple ST1s
Provide an audio-only endpoint to pair with a video-only endpoint, for example in a home theater situation where the AVR is at the rack but the display is too far to connect directly to the AVR

2G Mode Settings

The ST1 Audio Encoder / Decoder can work in a 2G Series devices while in 2G Mode, but requires it to be set within the device settings in order to be applied.

Apply 2G Mode

2G Mode is automatically applied to the unit when loading firmware A6.5.9-LTS

Instructions to Set 2G Mode manually can be found here

Enable Audio-Only

Standard 2G series and Ultra series Decoders expect video and audio to be sent together. In their default state, a 2G Series Decoder will not process audio unless there is an accompanying video signal. To set a Decoder to accept audio without a video signal, send this command via the CLI of the Decoder:

astparam s a_force_dual_output y;astparam save;sleep 1;reboot

The unit will reboot and accept audio independent of video. This must be applied to every 2G Series Decoder in a system that wishes to listen to an audio-only signal from a ST1 or an Audio-Extracting Encoder.