Versatile Connectivity: D4 offers a comprehensive range of input options, including HDMI ARC, Bluetooth, USB, U disk, optical fiber, coaxial, and RCA, ensuring compatibility with diverse audio sources and user preferences.

High-Fidelity Audio: Utilizing the ES9023P DAC for most inputs ensures high-resolution audio decoding and playback, delivering a high-fidelity listening experience.

2.1 Channel System Support: D4 seamlessly integrates with a subwoofer, creating a 2.1-channel system. This enhances the overall audio experience with powerful bass reproduction, ideal for movies, music with deep bass lines, and immersive gaming.

Enhanced Mid-Frequency Performance: In TONE mode, D4 offers precise control over BASS, MIDDLE, and TREBLE frequencies. Adjustment range: (-12db) ~ (+12db)Notably, it excels in reproducing mid-range frequencies, resulting in clear and natural vocal reproduction and a more engaging listening experience within the 2.1-channel system. This accurate mid-range reproduction significantly contributes to the overall audio quality and immersion.

HDMI ARC Integration: D4 supports HDMI ARC input, enabling seamless connection to modern TVs. This allows for convenient audio playback from the TV, including streaming services, gaming consoles, and cable/satellite boxes, directly through the amplifier for a more immersive and high-quality audio experience.

Op-Amp Customization: The D4 features an op-amp socket, allowing users to swap out the included OPA1642 with other op-amp chips. This customization enables users to tailor the amplifier’s sound characteristics to their personal preferences, potentially achieving different sound textures, warmth, or detail.

Bluetooth Capabilities: supports Bluetooth 5.0 with AAC and SBC codecs. This allows for wireless audio streaming from compatible devices like smartphones, tablets, and computers.

Sampling Rate: The Bluetooth and USB inputs support sampling rates ranging from 44.1 kHz to 48 kHz, which are common audio sampling rates.

High-Resolution Support: The Optical, Coaxial, and HDMI ARC inputs support a maximum sampling rate of 192 kHz, enabling high-resolution audio playback for those sources.

This refined list highlights the key strengths of the D4 amplifier, emphasizing its versatility, audio quality, 2.1-channel capabilities, exceptional mid-frequency performance, and convenient HDMI ARC integration.