FIIO K7 [Official Japanese Product] Fiio Compact Desktop Headphone Amplifier with Built-in USB DAC, Dual Configuration, THX-AAA 788+

Equipped with Asahi Kasei Microdevices' latest DAC chip, the "AK4493SEQ," in a dual configuration: The K7 employs the latest DAC chip, the "AK4493SEQ," a redesign of Asahi Kasei Microdevices' (AKM) predecessor, the "AK4493EQ," using current high-quality sound technology. Designed based on advanced VELVET SOUND technology, the "AK4493SEQ" effectively reduces power consumption through optimized impedance, while delivering rich information, a sense of speed, and realistic spatial expression. Furthermore, a revised noise design has significantly improved the perceived noise level beyond the catalog specifications. Specified S/N ratios are up to 128dB, and THD+N is -115dB, achieving superior analog characteristics. Fully balanced design from DAC to headphone amplifier: The K7's audio circuit is based on the same architecture as the flagship K9 Pro ESS model, a fully balanced circuit consisting of six blocks: DAC, low-pass filter, volume control, buffer amplifier, preamplifier, and headphone amplifier. By thoroughly using differential signal inputs to each block, which is separated into left and right channels, mutual interference that can adversely affect sound quality is minimized, enabling higher-level music reproduction with greater signal fidelity.

Two "THX-AAA 788+" headphone amplifier circuits jointly developed by FiiO and THX: The K7 is equipped with the same "THX-AAA 788+" amplifier circuit as the K9 Pro ESS, FiiO's flagship desktop headphone amplifier. This amplifier circuit was jointly developed by FiiO and THX based on the "THX-AAA 788" circuit to deliver ideal detail and dynamics for all headphone playback, from high to low efficiency. The K7 features a fully balanced configuration, with two amplifiers, one per left and one per channel, delivering a maximum output of 2000mW at 32Ω load and 560mW at 300Ω load.

XMOS XUF208 Supports PCM 384kHz/32-bit and DSD256 Playback: The K7 uses the XMOS XUF208 USB decoding chip. This chip enables decoding of PCM up to 384kHz/32-bit and DSD up to DSD256 (Native) and DSD128 (DoP). Dual clock management technology ensures high-quality D/A conversion by always selecting the optimal clock for the input source.

Clean Independent Power Supply Circuit Design: The K7 uses a power supply circuit design that provides independent power to each circuit block to suppress power supply noise that can adversely affect sound quality. The power supplied from the 12V external switching power supply is kept clean by the low-noise LDOs responsible for each block, and then adjusted to the appropriate amount before being supplied to the components.