Techniques for improving the power efficiency of a playback device

A playback device comprising:

• a wireless communication interface;
• a switch-mode power supply (SMPS) configured to produce a supply voltage;
• processor circuitry coupled to the wireless communication interface and to the SMPS, the processor circuitry comprising at least one processor;
• amplifier circuitry coupled to the processor circuitry and the SMPS, the amplifier circuitry comprising an audio amplifier powered by the supply voltage from the SMPS;
• and
• at least one non-transitory computer-readable medium coupled to the at least one processor having stored thereon program instructions that are executable by the at least one processor such that the processor circuitry is configured to:
• after receipt of first audio data representing audio content via the wireless communication interface, produce second audio data based on the first audio data, the second audio data including a digital audio signal,
• forecast a target value of the supply voltage to be provided to the audio amplifier,
• at least in part during production of the second audio data and based on the target value of the supply voltage, produce a control signal associated with the second audio data, the control signal indicating the target value supply voltage for the audio amplifier, and
• communicate the control signal to the SMPS to cause the SMPS to vary the supply voltage for the audio amplifier based on the control signal;
• wherein the amplifier circuitry is configured to receive the second audio data from the processor circuitry and to generate, using the audio amplifier, an analog audio signal to drive a speaker based on the second audio data.

A method comprising:

• receiving, at a playback device, first audio data representing audio content;
• after receiving the first audio data, producing, with the playback device, second audio data based on the first audio data, the second audio data including a digital audio signal;
• forecasting, by the playback device, a target value of a supply voltage to be provided to an audio amplifier of the playback device;
• producing, at least in part during production of the second audio data and based on the target value of the supply voltage, a control signal associated with the second audio data, the control signal indicating the target value supply voltage for the audio amplifier;
• communicating the control signal to a switch mode power supply (SMPS) of the playback device to cause the SMPS to vary the supply voltage for the audio amplifier based on the control signal;
• and
• playing back, via the audio amplifier and at least one speaker coupled to the audio amplifier, audio content based on the second audio data.