FiiO K9 Pro ESS | Desktop Bluetooth DAC and Amp

Introducing the FiiO K9 Pro ESS, a High-Performance Bluetooth DAC and Amp Boasting Pure, Clean Sound

• Dual ES9038PRO DACs ensure high-precision audio decoding with ultra-low distortion
• Designed for home audio setups (Desktop USB audio + active speakers)
  
• Supports MQA decoding and Bluetooth LDAC for studio-quality audio
• Offers fully balanced circuitry for superior sound quality and separation
• Versatile Connectivity: Includes USB, Bluetooth, optical, coaxial, and balanced inputs/outputs

K9 Pro ESS

Inside the K9 Pro ESS are two ES9038PRO DAC chips, specifically designed for maximum performance in desktop-grade equipment. One ES9038PRO chip, with all its 8 parallel outputs, is used for each channel to achieve richly detailed sound with minimal distortion.

Pure, Clean Sound

The THX AAA 788+ chips used in the K9 Pro ESS provide exemplary details and dynamics no matter if you are using low or high-impedance headphones. The K9 Pro ESS can produce 1100mW under a 300-ohm load and 2100mW under a 32-ohm load undistorted, and 50% higher than the original THX AAA 788 amplifier chips.

Precision Design

Fully Differential, Fully Balanced
Fully differential signals go through the DAC, volume adjustment, and amp for a truly balanced design. Such a design ensures minimal interference between different components in order to fully maintain all details and large dynamic swings in music for unmatched sound quality.

Separated Analog and Digital Sections
The PCB of the K9 Pro ESS uses a partitioned layout, where the power supply and signals are not only separated, but the analog signal loop is also put in an independent section guaranteeing the integrity of the audio signal being processed.

Six-Stage Audio Circuit
Every audio signal goes through a mammoth 6-stage circuit to reproduce music as faithfully and as detailed as possible.

Robust Power Supply

Linear Power Supply
Electricity is the mother of sound, so special attention was paid to optimizing the K9 Pro ESS's power supply to ensure excellent sound. The K9 Pro ESS's linear power supply—with its low-frequency transformer and four massive 4700uF capacitors—makes sure that the rest of the system gets abundant clean power.

Isolated Digital and Analog Power Delivery
The digital portions of the K9 Pro ESS physically receive power separately from the analog portions for effective shielding against audio interference between the two circuits. This ensures pure and faithful reproduction of your music.

LDOs for Each Circuit Stage
Besides the special high-performance linear power supply, the power stabilization and filtering within the audio circuit is also a big contributor to the K9 Pro ESS's excellent sound. Specifically, in each stage of the audio circuit, ultra-low-noise LDOs are employed for voltage regulation.

Precision Clock Management

A dual-mode clock management design is utilized for the K9 Pro ESS. Under USB and Bluetooth decoding, dual asynchronous femtosecond clocks are used, while under optical and coaxial decoding, automatic PLL clocks are employed. A more precise clock management system makes it easier to handle any kind of source and maintain the maximum quality possible.

MQA Renderer, Lossless Sound Reproduction

The K9 Pro ESS supports the unfolding of MQA tracks, allowing you to listen to high-resolution audio files that are not only reasonably sized, but also retain master-level sound quality that bring you directly into the recording studio.

Hi-Res Bluetooth

The K9 Pro ESS employs the Qualcomm QCC5124 chip to handle Bluetooth duties, with support for formats such as LDAC, aptX HD, and aptX Adaptive. This chip ensures that Bluetooth connections are both reliable and quick, satisfying both the low latency needs for games/videos and the high bitrate necessary for high-resolution audio.

Volume Control

Adjusting the volume may look like a simple concept, but a good execution of it is crucial to an excellent audio experience. The ADC curve reconstruction method of volume adjustment used in the K9 Pro ESS effectively minimizes any left-right channel volume imbalance and noise. It also results in a smooth change of volume across all levels. This attention paid to the simple process of volume adjustment is just another layer to making sure you truly savor your music with the K9 Pro ESS.

The RGB indicator lights surrounding the volume knob light up differently depending on the currently playing sample rate.

Three Gain Levels

Choose between high, medium, and low with a physical switch to fit your needs when listening to your particular pair of headphones. Thanks to the pure hardware gain circuit, even when listening at low gain with high-sensitivity headphones both dynamic range and musical fidelity remain un-compromised.

Custom Stand

The included custom stand not only reduces the amount of space the K9 Pro ESS takes on your desktop, it also allows for more efficient dissipation of heat through convection, making the stand a true example of both form and function.

Specifications

• Power Supply: AC + built-in Linear Power Supply
• Digital Input Interface: USB, Optical, Coaxial, Bluetooth
• Analog Input Interface: RCA, 4.4mm BAL
• USB Interface: USB-C
• Headphone Output:
  • BAL XLR + 4.4mm
  • SE 6.35mm + 3.5mm
• Line Out:
  • RCA
  • BAL XLR
• Audio Processing Layers: 6 layers
• Clock Design: Dual mode dual crystal oscillator
• USB Chip: XMOS XUF208
• MQA: Renderer
• Bluetooth: QCC5124
• Audio Clock: High precision PLL + dual crystal oscillator
• DAC: (2x) ES9039PRO
• Output Mode: HP/LO/DAC
• Amp Chip: Dual THX AAA 788+
• Output Power (PO)
  • 2100mW(32 Ω),281mW(300 Ω)
  • Balance: 2100mW(32 Ω),1100mW(300 Ω)
• Output Power (BAL)
  • 2100mW (32Ω)
  • 1100mW (300Ω)
• Peak Output Voltage: 52Vpp
• THD+N: ≤ 0.00025%
• SNR: ≥ 129dB
• APP Control: Android/iOS
• Dimensions: 8" x 9" x 3" (excluding feet)
• Weight: 6lbs
• Material: Aluminum alloy