TAS2781 Class-D Amplifier Texas Instruments TAS2781 Class-D Amplifier is optimized with real-time integrated speaker protection and audio processing. The TAS2781 delivers 25W of continuous power into a 4Ω load with less than 1% THD+N at a supply voltage of 18V. The device's broad voltage input range and high output power are ideal for battery or line-powered systems.