FIIO K9 AKM Headphone Amplifier Japanese Retailer Product with Serial Asahi Kasei AK4191EQ AK4499EX USB DAC Headphone Amplifier [Official Number]

Equipped with AKM's flagship separate DAC system, the AK4191EQ + AK4499EX. The K9 AKM features AKM's flagship DAC, the AK4191EQ + AK4499EX. This DAC system employs a separate DAC architecture consisting of the AK4191EQ, which handles digital filtering and delta-sigma modulation, and the AK4499EX, which handles the analog DAC. In addition to separating the completely different functions of digital and analog processing at the chip level, this system also combines DWA Routing Technology, which equalizes individual differences in resistor elements, improving the S/N ratio at the chip level. This is a new-generation DAC system that not only achieves numerical improvements over its predecessor flagship model, but also meticulously craftsmanship to deliver the ultimate in audio quality. Equipped with the "THX-AAA 788+" headphone amplifier circuit, developed in collaboration with THX: The K9 AKM features the "THX-AAA 788+" amplifier circuit, which employs high-quality feedforward technology to correct distortion that occurs during signal amplification. This amplifier circuit, jointly developed by FIIO and THX, is based on the "THX-AAA 788" circuit, which was designed to deliver the ultimate in transparency and pure sound. By incorporating two amplifier circuits, one per left and one per channel, the K9 AKM delivers high output power—up to 2000mW at a 32Ω load and 780mW at a 300Ω load—while maintaining low distortion. Fully Balanced Design from DAC to Headphone Amplifier: The K9 AKM's audio circuitry is fully balanced, with differential signal inputs to separate left and right channel circuits, from the DAC to the volume control and headphone amplifier. The audio circuitry is divided into six blocks: DAC, low-pass filter, volume control, buffer amplifier, preamplifier, and headphone amplifier. Each block has been meticulously designed to deliver the powerful sound you expect from a desktop device while retaining the exquisite detail. Furthermore, by separating and optimizing the layout of each major processing section on the board, adverse mutual interference is minimized, enabling high-quality music playback with exceptional signal fidelity. Equipped with XMOS's "XUF208" and two ultra-high-precision crystal oscillators: The K9 AKM uses the XMOS "XUF208" USB decoding chip. This chip enables PCM decoding up to 768kHz/32-bit and DSD decoding up to DSD512. Dual clock management technology constantly selects the optimal clock for the input source, ensuring high-quality D/A conversion with exceptional signal fidelity. Clean Power Supply Design: The Source of High-Quality Sound: The K9 AKM's internal power transformer, combined with four 4700uF high-capacity capacitors, provides a clean power supply to the internal audio circuitry. Separate power supplies for the digital and analog sections suppress power supply noise that can adversely affect sound quality and minimize mutual interference between each block. Furthermore, each circuit block is kept clean by a low-noise LDO, and each block receives the appropriate amount of boosted power. This thorough power supply design delivers a high S/N ratio and rich sound image reproduction. Equipped with ADC volume control for precise volume adjustment: The K9 AKM features an ADC volume control function for volume adjustment. Unlike analog volume controls, which directly manipulate a variable resistor through a music signal, this method controls the volume IC based on the analog-to-digital conversion of the volume knob's rotational change. While providing 120 levels of precise volume adjustment, it successfully eliminates the left-right volume difference and noise that are common problems with analog volume controls. [Equipped with a wide range of input and output terminals to suit any application] The K9 AKM is equipped with a wide range of input and output terminals, so you can not only connect it to a PC, but also to various digital devices to enjoy a high-quality audio experience, or you can easily incorporate it as part of an audio system you already own. Equipped with Qualcomm's QCC5124 Bluetooth SoC, the K9 AKM also functions as a high-performance Bluetooth receiver, supporting high-quality Bluetooth codecs such as LDAC, aptX HD, and aptX Adaptive. The K9 AKM's wireless connection delivers both high data rate and low latency, allowing you to enjoy not only music but also more immersive gaming and video experiences. [UAC1.0/2.0 Connection Mode Switchable] The K9 AKM supports both UAC1.0 and 2.0 connections, ensuring compatibility with a wide range of devices, including home game consoles. You can easily switch connection modes using the FIIO Control app available for smartphones. [More advanced settings possible with the FIIO Control App] By connecting the K9 AKM to the FIIO Control App available for smartphones, you can customize the digital filters, various equalizer functions, channel balance, LED display settings, and more to suit your individual preferences. *The equalizer function is only available when connected via Bluetooth. The K9 AKM is a high-performance model equipped with the flagship audio DAC chip system "AK4191EQ + AK4499EX" manufactured by Asahi Kasei Microdevices (hereinafter referred to as AKM), and its audio circuitry and board layout are designed in common with the top-of-the-line model, the K9 Pro ESS.